merge trunk

49 files changed, 1692 insertions, 1439 deletions

diff --git a/generic/tclBasic.c b/generic/tclBasic.c
index 537750e..db365e3 100644
--- a/generic/tclBasic.c
+++ b/generic/tclBasic.c
@@ -1708,9 +1708,9 @@ Tcl_HideCommand(
      */
 
     if (strstr(hiddenCmdToken, "::") != NULL) {
-	Tcl_AppendResult(interp,
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		"cannot use namespace qualifiers in hidden command"
-		" token (rename)", NULL);
+		" token (rename)", -1));
         Tcl_SetErrorCode(interp, "TCL", "VALUE", "HIDDENTOKEN", NULL);
 	return TCL_ERROR;
     }
@@ -1733,8 +1733,9 @@ Tcl_HideCommand(
      */
 
     if (cmdPtr->nsPtr != iPtr->globalNsPtr) {
-	Tcl_AppendResult(interp, "can only hide global namespace commands"
-		" (use rename then hide)", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "can only hide global namespace commands (use rename then hide)",
+                -1));
         Tcl_SetErrorCode(interp, "TCL", "HIDE", "NON_GLOBAL", NULL);
 	return TCL_ERROR;
     }
@@ -1758,8 +1759,9 @@ Tcl_HideCommand(
 
     hPtr = Tcl_CreateHashEntry(hiddenCmdTablePtr, hiddenCmdToken, &isNew);
     if (!isNew) {
-	Tcl_AppendResult(interp, "hidden command named \"", hiddenCmdToken,
-		"\" already exists", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "hidden command named \"%s\" already exists",
+                hiddenCmdToken));
         Tcl_SetErrorCode(interp, "TCL", "HIDE", "ALREADY_HIDDEN", NULL);
 	return TCL_ERROR;
     }
@@ -1861,8 +1863,9 @@ Tcl_ExposeCommand(
      */
 
     if (strstr(cmdName, "::") != NULL) {
-	Tcl_AppendResult(interp, "cannot expose to a namespace "
-		"(use expose to toplevel, then rename)", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "cannot expose to a namespace (use expose to toplevel, then rename)",
+                -1));
         Tcl_SetErrorCode(interp, "TCL", "EXPOSE", "NON_GLOBAL", NULL);
 	return TCL_ERROR;
     }
@@ -1877,8 +1880,8 @@ Tcl_ExposeCommand(
 	hPtr = Tcl_FindHashEntry(hiddenCmdTablePtr, hiddenCmdToken);
     }
     if (hPtr == NULL) {
-	Tcl_AppendResult(interp, "unknown hidden command \"", hiddenCmdToken,
-		"\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "unknown hidden command \"%s\"", hiddenCmdToken));
         Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "HIDDENTOKEN",
                 hiddenCmdToken, NULL);
 	return TCL_ERROR;
@@ -1897,9 +1900,9 @@ Tcl_ExposeCommand(
 	 * than 'nicely' erroring out ?
 	 */
 
-	Tcl_AppendResult(interp,
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		"trying to expose a non-global command namespace command",
-		NULL);
+		-1));
 	return TCL_ERROR;
     }
 
@@ -1916,8 +1919,8 @@ Tcl_ExposeCommand(
 
     hPtr = Tcl_CreateHashEntry(&nsPtr->cmdTable, cmdName, &isNew);
     if (!isNew) {
-	Tcl_AppendResult(interp, "exposed command \"", cmdName,
-		"\" already exists", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "exposed command \"%s\" already exists", cmdName));
         Tcl_SetErrorCode(interp, "TCL", "EXPOSE", "COMMAND_EXISTS", NULL);
 	return TCL_ERROR;
     }
@@ -2497,9 +2500,10 @@ TclRenameCommand(
     cmd = Tcl_FindCommand(interp, oldName, NULL, /*flags*/ 0);
     cmdPtr = (Command *) cmd;
     if (cmdPtr == NULL) {
-	Tcl_AppendResult(interp, "can't ",
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't %s \"%s\": command doesn't exist",
 		((newName == NULL)||(*newName == '\0'))? "delete":"rename",
-		" \"", oldName, "\": command doesn't exist", NULL);
+		oldName));
         Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COMMAND", oldName, NULL);
 	return TCL_ERROR;
     }
@@ -2529,15 +2533,15 @@ TclRenameCommand(
 	    TCL_CREATE_NS_IF_UNKNOWN, &newNsPtr, &dummy1, &dummy2, &newTail);
 
     if ((newNsPtr == NULL) || (newTail == NULL)) {
-	Tcl_AppendResult(interp, "can't rename to \"", newName,
-		"\": bad command name", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't rename to \"%s\": bad command name", newName));
         Tcl_SetErrorCode(interp, "TCL", "VALUE", "COMMAND", NULL);
 	result = TCL_ERROR;
 	goto done;
     }
     if (Tcl_FindHashEntry(&newNsPtr->cmdTable, newTail) != NULL) {
-	Tcl_AppendResult(interp, "can't rename to \"", newName,
-		 "\": command already exists", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't rename to \"%s\": command already exists", newName));
         Tcl_SetErrorCode(interp, "TCL", "OPERATION", "RENAME",
                 "TARGET_EXISTS", NULL);
 	result = TCL_ERROR;
@@ -3538,9 +3542,9 @@ OldMathFuncProc(
 	     * We have a non-numeric argument.
 	     */
 
-	    Tcl_SetResult(interp,
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "argument to math function didn't have numeric value",
-		    TCL_STATIC);
+		    -1));
 	    TclCheckBadOctal(interp, Tcl_GetString(valuePtr));
 	    ckfree(args);
 	    return TCL_ERROR;
@@ -3827,9 +3831,8 @@ TclInterpReady(
      */
 
     if (iPtr->flags & DELETED) {
-	/* JJM - Superfluous Tcl_ResetResult call removed. */
-	Tcl_AppendResult(interp,
-		"attempt to call eval in deleted interpreter", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to call eval in deleted interpreter", -1));
 	Tcl_SetErrorCode(interp, "TCL", "IDELETE",
 		"attempt to call eval in deleted interpreter", NULL);
 	return TCL_ERROR;
@@ -3857,8 +3860,8 @@ TclInterpReady(
 	return TCL_OK;
     }
 
-    Tcl_AppendResult(interp,
-	    "too many nested evaluations (infinite loop?)", NULL);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+	    "too many nested evaluations (infinite loop?)", -1));
     Tcl_SetErrorCode(interp, "TCL", "LIMIT", "STACK", NULL);
     return TCL_ERROR;
 }
@@ -3992,8 +3995,7 @@ Tcl_Canceled(
             }
         }
 
-        Tcl_ResetResult(interp);
-        Tcl_AppendResult(interp, message, NULL);
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(message, -1));
         Tcl_SetErrorCode(interp, "TCL", "CANCEL", id, message, NULL);
     }
 
@@ -4616,8 +4618,8 @@ TEOV_NotFound(
 
     cmdPtr = TEOV_LookupCmdFromObj(interp, newObjv[0], lookupNsPtr);
     if (cmdPtr == NULL) {
-	Tcl_AppendResult(interp, "invalid command name \"",
-		TclGetString(objv[0]), "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "invalid command name \"%s\"", TclGetString(objv[0])));
         Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COMMAND",
                 TclGetString(objv[0]), NULL);
 
@@ -6285,11 +6287,11 @@ ProcessUnexpectedResult(
 
     Tcl_ResetResult(interp);
     if (returnCode == TCL_BREAK) {
-	Tcl_AppendResult(interp,
-		"invoked \"break\" outside of a loop", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"invoked \"break\" outside of a loop", -1));
     } else if (returnCode == TCL_CONTINUE) {
-	Tcl_AppendResult(interp,
-		"invoked \"continue\" outside of a loop", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"invoked \"continue\" outside of a loop", -1));
     } else {
 	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
 		"command returned bad code: %d", returnCode));
@@ -6624,7 +6626,8 @@ TclObjInvoke(
     }
 
     if ((objc < 1) || (objv == NULL)) {
-	Tcl_AppendResult(interp, "illegal argument vector", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "illegal argument vector", -1));
 	return TCL_ERROR;
     }
 
@@ -6642,8 +6645,8 @@ TclObjInvoke(
 	hPtr = Tcl_FindHashEntry(hTblPtr, cmdName);
     }
     if (hPtr == NULL) {
-	Tcl_AppendResult(interp, "invalid hidden command name \"",
-		cmdName, "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "invalid hidden command name \"%s\"", cmdName));
         Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "HIDDENTOKEN", cmdName,
                 NULL);
 	return TCL_ERROR;
@@ -7269,7 +7272,8 @@ ExprIsqrtFunc(
     return TCL_OK;
 
   negarg:
-    Tcl_SetResult(interp, "square root of negative argument", TCL_STATIC);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+            "square root of negative argument", -1));
     Tcl_SetErrorCode(interp, "ARITH", "DOMAIN",
 	    "domain error: argument not in valid range", NULL);
     return TCL_ERROR;
@@ -8319,9 +8323,8 @@ TclNRTailcallObjCmd(
     }
 
     if (!iPtr->varFramePtr->isProcCallFrame) {	/* or is upleveled */
-        Tcl_SetResult(interp,
-                "tailcall can only be called from a proc or lambda",
-                TCL_STATIC);
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "tailcall can only be called from a proc or lambda", -1));
         Tcl_SetErrorCode(interp, "TCL", "TAILCALL", "ILLEGAL", NULL);
 	return TCL_ERROR;
     }
@@ -8480,8 +8483,8 @@ TclNRYieldObjCmd(
     }
 
     if (!corPtr) {
-	Tcl_SetResult(interp, "yield can only be called in a coroutine",
-		TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "yield can only be called in a coroutine", -1));
 	Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "ILLEGAL_YIELD", NULL);
 	return TCL_ERROR;
     }
@@ -8514,8 +8517,8 @@ TclNRYieldToObjCmd(
     }
 
     if (!corPtr) {
-	Tcl_SetResult(interp, "yieldto can only be called in a coroutine",
-		TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "yieldto can only be called in a coroutine", -1));
 	Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "ILLEGAL_YIELD", NULL);
 	return TCL_ERROR;
     }
@@ -8763,8 +8766,8 @@ NRCoroutineActivateCallback(
          */
 
         if (corPtr->stackLevel != stackLevel) {
-            Tcl_SetResult(interp, "cannot yield: C stack busy",
-                    TCL_STATIC);
+            Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                    "cannot yield: C stack busy", -1));
             Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "CANT_YIELD",
                     NULL);
             return TCL_ERROR;
@@ -8823,8 +8826,8 @@ NRCoroInjectObjCmd(
 
     cmdPtr = (Command *) Tcl_GetCommandFromObj(interp, objv[1]);
     if ((!cmdPtr) || (cmdPtr->nreProc != TclNRInterpCoroutine)) {
-        Tcl_AppendResult(interp, "can only inject a command into a coroutine",
-                NULL);
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "can only inject a command into a coroutine", -1));
         Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COROUTINE",
                 TclGetString(objv[1]), NULL);
         return TCL_ERROR;
@@ -8832,8 +8835,8 @@ NRCoroInjectObjCmd(
 
     corPtr = cmdPtr->objClientData;
     if (!COR_IS_SUSPENDED(corPtr)) {
-        Tcl_AppendResult(interp,
-                "can only inject a command into a suspended coroutine", NULL);
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "can only inject a command into a suspended coroutine", -1));
         Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "ACTIVE", NULL);
         return TCL_ERROR;
     }
@@ -8860,9 +8863,9 @@ TclNRInterpCoroutine(
     CoroutineData *corPtr = clientData;
 
     if (!COR_IS_SUSPENDED(corPtr)) {
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "coroutine \"", Tcl_GetString(objv[0]),
-		"\" is already running", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "coroutine \"%s\" is already running",
+                Tcl_GetString(objv[0])));
 	Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "BUSY", NULL);
 	return TCL_ERROR;
     }
@@ -8943,22 +8946,24 @@ TclNRCoroutineObjCmd(
 	    &nsPtr, &altNsPtr, &cxtNsPtr, &procName);
 
     if (nsPtr == NULL) {
-	Tcl_AppendResult(interp, "can't create procedure \"", fullName,
-		"\": unknown namespace", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't create procedure \"%s\": unknown namespace",
+                fullName));
         Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "NAMESPACE", NULL);
 	return TCL_ERROR;
     }
     if (procName == NULL) {
-	Tcl_AppendResult(interp, "can't create procedure \"", fullName,
-		"\": bad procedure name", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't create procedure \"%s\": bad procedure name",
+                fullName));
         Tcl_SetErrorCode(interp, "TCL", "VALUE", "COMMAND", fullName, NULL);
 	return TCL_ERROR;
     }
     if ((nsPtr != iPtr->globalNsPtr)
 	    && (procName != NULL) && (procName[0] == ':')) {
-	Tcl_AppendResult(interp, "can't create procedure \"", procName,
-		"\" in non-global namespace with name starting with \":\"",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't create procedure \"%s\" in non-global namespace with"
+                " name starting with \":\"", procName));
         Tcl_SetErrorCode(interp, "TCL", "VALUE", "COMMAND", procName, NULL);
 	return TCL_ERROR;
     }
diff --git a/generic/tclBinary.c b/generic/tclBinary.c
index 444e7fa..a1e836e 100644
--- a/generic/tclBinary.c
+++ b/generic/tclBinary.c
@@ -873,9 +873,9 @@ BinaryFormatCmd(
 		if (count == BINARY_ALL) {
 		    count = listc;
 		} else if (count > listc) {
-		    Tcl_AppendResult(interp,
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			    "number of elements in list does not match count",
-			    NULL);
+			    -1));
 		    return TCL_ERROR;
 		}
 	    }
@@ -884,9 +884,8 @@ BinaryFormatCmd(
 
 	case 'x':
 	    if (count == BINARY_ALL) {
-		Tcl_AppendResult(interp,
-			"cannot use \"*\" in format string with \"x\"",
-			NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"cannot use \"*\" in format string with \"x\"", -1));
 		return TCL_ERROR;
 	    } else if (count == BINARY_NOCOUNT) {
 		count = 1;
@@ -1198,8 +1197,9 @@ BinaryFormatCmd(
 
  badValue:
     Tcl_ResetResult(interp);
-    Tcl_AppendResult(interp, "expected ", errorString,
-	" string but got \"", errorValue, "\" instead", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "expected %s string but got \"%s\" instead",
+	    errorString, errorValue));
     return TCL_ERROR;
 
  badCount:
@@ -1217,12 +1217,13 @@ BinaryFormatCmd(
 
 	Tcl_UtfToUniChar(errorString, &ch);
 	buf[Tcl_UniCharToUtf(ch, buf)] = '\0';
-	Tcl_AppendResult(interp, "bad field specifier \"", buf, "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"bad field specifier \"%s\"", buf));
 	return TCL_ERROR;
     }
 
  error:
-    Tcl_AppendResult(interp, errorString, NULL);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(errorString, -1));
     return TCL_ERROR;
 }
 
@@ -1586,12 +1587,13 @@ BinaryScanCmd(
 
 	Tcl_UtfToUniChar(errorString, &ch);
 	buf[Tcl_UniCharToUtf(ch, buf)] = '\0';
-	Tcl_AppendResult(interp, "bad field specifier \"", buf, "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"bad field specifier \"%s\"", buf));
 	return TCL_ERROR;
     }
 
  error:
-    Tcl_AppendResult(interp, errorString, NULL);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(errorString, -1));
     return TCL_ERROR;
 }
 
diff --git a/generic/tclCkalloc.c b/generic/tclCkalloc.c
index 5b5a0d6..6443975 100644
--- a/generic/tclCkalloc.c
+++ b/generic/tclCkalloc.c
@@ -815,15 +815,16 @@ MemoryCmd(
     size_t len;
 
     if (argc < 2) {
-	Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
-		" option [args..]\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "wrong # args: should be \"%s option [args..]\"", argv[0]));
 	return TCL_ERROR;
     }
 
-    if ((strcmp(argv[1],"active") == 0) || (strcmp(argv[1],"display") == 0)) {
+    if (strcmp(argv[1], "active") == 0 || strcmp(argv[1], "display") == 0) {
 	if (argc != 3) {
-	    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
-		    " ", argv[1], " file\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "wrong # args: should be \"%s %s file\"",
+                    argv[0], argv[1]));
 	    return TCL_ERROR;
 	}
 	fileName = Tcl_TranslateFileName(interp, argv[2], &buffer);
@@ -833,7 +834,8 @@ MemoryCmd(
 	result = Tcl_DumpActiveMemory(fileName);
 	Tcl_DStringFree(&buffer);
 	if (result != TCL_OK) {
-	    Tcl_AppendResult(interp, "error accessing ", argv[2], NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf("error accessing %s: %s",
+                    argv[2], Tcl_PosixError(interp)));
 	    return TCL_ERROR;
 	}
 	return TCL_OK;
@@ -857,17 +859,17 @@ MemoryCmd(
 		"maximum bytes allocated", (unsigned long)maximum_bytes_malloced));
 	return TCL_OK;
     }
-    if (strcmp(argv[1],"init") == 0) {
+    if (strcmp(argv[1], "init") == 0) {
 	if (argc != 3) {
 	    goto bad_suboption;
 	}
 	init_malloced_bodies = (strcmp(argv[2],"on") == 0);
 	return TCL_OK;
     }
-    if (strcmp(argv[1],"objs") == 0) {
+    if (strcmp(argv[1], "objs") == 0) {
 	if (argc != 3) {
-	    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
-		    " objs file\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "wrong # args: should be \"%s objs file\"", argv[0]));
 	    return TCL_ERROR;
 	}
 	fileName = Tcl_TranslateFileName(interp, argv[2], &buffer);
@@ -876,7 +878,9 @@ MemoryCmd(
 	}
 	fileP = fopen(fileName, "w");
 	if (fileP == NULL) {
-	    Tcl_AppendResult(interp, "cannot open output file", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "cannot open output file: %s",
+                    Tcl_PosixError(interp)));
 	    return TCL_ERROR;
 	}
 	TclDbDumpActiveObjects(fileP);
@@ -886,8 +890,8 @@ MemoryCmd(
     }
     if (strcmp(argv[1],"onexit") == 0) {
 	if (argc != 3) {
-	    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
-		    " onexit file\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "wrong # args: should be \"%s onexit file\"", argv[0]));
 	    return TCL_ERROR;
 	}
 	fileName = Tcl_TranslateFileName(interp, argv[2], &buffer);
@@ -901,8 +905,8 @@ MemoryCmd(
     }
     if (strcmp(argv[1],"tag") == 0) {
 	if (argc != 3) {
-	    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
-		    " tag string\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "wrong # args: should be \"%s tag string\"", argv[0]));
 	    return TCL_ERROR;
 	}
 	if ((curTagPtr != NULL) && (curTagPtr->refCount == 0)) {
@@ -939,19 +943,20 @@ MemoryCmd(
 	return TCL_OK;
     }
 
-    Tcl_AppendResult(interp, "bad option \"", argv[1],
-	    "\": should be active, break_on_malloc, info, init, objs, onexit, "
-	    "tag, trace, trace_on_at_malloc, or validate", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+            "bad option \"%s\": should be active, break_on_malloc, info, "
+            "init, objs, onexit, tag, trace, trace_on_at_malloc, or validate",
+            argv[1]));
     return TCL_ERROR;
 
   argError:
-    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
-	    " ", argv[1], " count\"", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+            "wrong # args: should be \"%s %s count\"", argv[0], argv[1]));
     return TCL_ERROR;
 
   bad_suboption:
-    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
-	    " ", argv[1], " on|off\"", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+            "wrong # args: should be \"%s %s on|off\"", argv[0], argv[1]));
     return TCL_ERROR;
 }
 
@@ -981,8 +986,8 @@ CheckmemCmd(
     const char *argv[])		/* String values of arguments. */
 {
     if (argc != 2) {
-	Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
-		" fileName\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "wrong # args: should be \"%s fileName\"", argv[0]));
 	return TCL_ERROR;
     }
     tclMemDumpFileName = dumpFile;
diff --git a/generic/tclClock.c b/generic/tclClock.c
index 7fa4017..6d2976d 100644
--- a/generic/tclClock.c
+++ b/generic/tclClock.c
@@ -878,8 +878,8 @@ ConvertLocalToUTCUsingC(
 
     if (localErrno != 0
 	    || (fields->seconds == -1 && timeVal.tm_yday == -1)) {
-	Tcl_SetResult(interp, "time value too large/small to represent",
-		TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"time value too large/small to represent", -1));
 	return TCL_ERROR;
     }
     return TCL_OK;
@@ -1018,17 +1018,17 @@ ConvertUTCToLocalUsingC(
 
     tock = (time_t) fields->seconds;
     if ((Tcl_WideInt) tock != fields->seconds) {
-	Tcl_AppendResult(interp,
-		"number too large to represent as a Posix time", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"number too large to represent as a Posix time", -1));
 	Tcl_SetErrorCode(interp, "CLOCK", "argTooLarge", NULL);
 	return TCL_ERROR;
     }
     TzsetIfNecessary();
     timeVal = ThreadSafeLocalTime(&tock);
     if (timeVal == NULL) {
-	Tcl_AppendResult(interp,
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		"localtime failed (clock value may be too "
-		"large/small to represent)", NULL);
+		"large/small to represent)", -1));
 	Tcl_SetErrorCode(interp, "CLOCK", "localtimeFailed", NULL);
 	return TCL_ERROR;
     }
diff --git a/generic/tclCmdAH.c b/generic/tclCmdAH.c
index f09ee70..5ca5cf8 100644
--- a/generic/tclCmdAH.c
+++ b/generic/tclCmdAH.c
@@ -194,7 +194,8 @@ Tcl_CaseObjCmd(
 
 	if (i == caseObjc-1) {
 	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "extra case pattern with no body", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "extra case pattern with no body", -1));
 	    return TCL_ERROR;
 	}
 
@@ -409,8 +410,9 @@ Tcl_CdObjCmd(
     } else {
 	result = Tcl_FSChdir(dir);
 	if (result != TCL_OK) {
-	    Tcl_AppendResult(interp, "couldn't change working directory to \"",
-		    TclGetString(dir), "\": ", Tcl_PosixError(interp), NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "couldn't change working directory to \"%s\": %s",
+		    TclGetString(dir), Tcl_PosixError(interp)));
 	    result = TCL_ERROR;
 	}
     }
@@ -642,8 +644,9 @@ EncodingDirsObjCmd(
 
     dirListObj = objv[2];
     if (Tcl_SetEncodingSearchPath(dirListObj) == TCL_ERROR) {
-	Tcl_AppendResult(interp, "expected directory list but got \"",
-		TclGetString(dirListObj), "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"expected directory list but got \"%s\"",
+		TclGetString(dirListObj)));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "ENCODING", "BADPATH",
 		NULL);
 	return TCL_ERROR;
@@ -1165,9 +1168,9 @@ FileAttrAccessTimeCmd(
 	tval.modtime = buf.st_mtime;
 
 	if (Tcl_FSUtime(objv[1], &tval) != 0) {
-	    Tcl_AppendResult(interp, "could not set access time for file \"",
-		    TclGetString(objv[1]), "\": ", Tcl_PosixError(interp),
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "could not set access time for file \"%s\": %s",
+		    TclGetString(objv[1]), Tcl_PosixError(interp)));
 	    return TCL_ERROR;
 	}
 
@@ -1237,9 +1240,9 @@ FileAttrModifyTimeCmd(
 	tval.modtime = newTime;
 
 	if (Tcl_FSUtime(objv[1], &tval) != 0) {
-	    Tcl_AppendResult(interp, "could not set modification time for "
-		    "file \"", TclGetString(objv[1]), "\": ",
-		    Tcl_PosixError(interp), NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "could not set modification time for file \"%s\": %s",
+		    TclGetString(objv[1]), Tcl_PosixError(interp)));
 	    return TCL_ERROR;
 	}
 
@@ -1842,7 +1845,7 @@ PathFilesystemCmd(
     }
     fsInfo = Tcl_FSFileSystemInfo(objv[1]);
     if (fsInfo == NULL) {
-	Tcl_SetResult(interp, "unrecognised path", TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj("unrecognised path", -1));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "FILESYSTEM",
 		Tcl_GetString(objv[1]), NULL);
 	return TCL_ERROR;
@@ -1990,8 +1993,9 @@ PathSplitCmd(
     }
     res = Tcl_FSSplitPath(objv[1], NULL);
     if (res == NULL) {
-	Tcl_AppendResult(interp, "could not read \"", TclGetString(objv[1]),
-		"\": no such file or directory", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"could not read \"%s\": no such file or directory",
+		TclGetString(objv[1])));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "PATHSPLIT", "NONESUCH",
 		NULL);
 	return TCL_ERROR;
@@ -2092,7 +2096,8 @@ FilesystemSeparatorCmd(
 	Tcl_Obj *separatorObj = Tcl_FSPathSeparator(objv[1]);
 
 	if (separatorObj == NULL) {
-	    Tcl_SetResult(interp, "unrecognised path", TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "unrecognised path", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "FILESYSTEM",
 		    Tcl_GetString(objv[1]), NULL);
 	    return TCL_ERROR;
@@ -2211,9 +2216,9 @@ GetStatBuf(
 
     if (status < 0) {
 	if (interp != NULL) {
-	    Tcl_AppendResult(interp, "could not read \"",
-		    TclGetString(pathPtr), "\": ",
-		    Tcl_PosixError(interp), NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "could not read \"%s\": %s",
+		    TclGetString(pathPtr), Tcl_PosixError(interp)));
 	}
 	return TCL_ERROR;
     }
@@ -2648,7 +2653,8 @@ TclNRForeachCmd(
 	TclListObjGetElements(NULL, statePtr->vCopyList[i],
 		&statePtr->varcList[i], &statePtr->varvList[i]);
 	if (statePtr->varcList[i] < 1) {
-	    Tcl_AppendResult(interp, "foreach varlist is empty", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "foreach varlist is empty", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "FOREACH",
 		    "NEEDVARS", NULL);
 	    result = TCL_ERROR;
diff --git a/generic/tclCmdIL.c b/generic/tclCmdIL.c
index b312026..14e0092 100644
--- a/generic/tclCmdIL.c
+++ b/generic/tclCmdIL.c
@@ -27,15 +27,15 @@
  */
 
 typedef struct SortElement {
-    union {                     /* The value that we sorting by. */
+    union {			/* The value that we sorting by. */
 	const char *strValuePtr;
 	long intValue;
 	double doubleValue;
 	Tcl_Obj *objValuePtr;
     } collationKey;
-    union {             	/* Object being sorted, or its index. */
-        Tcl_Obj *objPtr;
-        int index;
+    union {			/* Object being sorted, or its index. */
+	Tcl_Obj *objPtr;
+	int index;
     } payload;
     struct SortElement *nextPtr;/* Next element in the list, or NULL for end
 				 * of list. */
@@ -229,8 +229,9 @@ TclNRIfObjCmd(
     Tcl_Obj *boolObj;
 
     if (objc <= 1) {
-	Tcl_AppendResult(interp, "wrong # args: no expression after \"",
-		TclGetString(objv[0]), "\" argument", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"wrong # args: no expression after \"%s\" argument",
+		TclGetString(objv[0])));
 	Tcl_SetErrorCode(interp, "TCL", "WRONGARGS", NULL);
 	return TCL_ERROR;
     }
@@ -319,8 +320,9 @@ IfConditionCallback(
 	 */
 
 	if (i >= objc) {
-	    Tcl_AppendResult(interp, "wrong # args: ",
-		    "no expression after \"", clause, "\" argument", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "wrong # args: no expression after \"%s\" argument",
+		    clause));
 	    Tcl_SetErrorCode(interp, "TCL", "WRONGARGS", NULL);
 	    return TCL_ERROR;
 	}
@@ -345,8 +347,9 @@ IfConditionCallback(
 	}
     }
     if (i < objc - 1) {
-	Tcl_AppendResult(interp, "wrong # args: ",
-		"extra words after \"else\" clause in \"if\" command", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"wrong # args: extra words after \"else\" clause in \"if\" command",
+		-1));
 	Tcl_SetErrorCode(interp, "TCL", "WRONGARGS", NULL);
 	return TCL_ERROR;
     }
@@ -361,9 +364,9 @@ IfConditionCallback(
     return TclNREvalObjEx(interp, objv[i], 0, iPtr->cmdFramePtr, i);
 
   missingScript:
-    clause = TclGetString(objv[i-1]);
-    Tcl_AppendResult(interp, "wrong # args: no script following \"", clause,
-	    "\" argument", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "wrong # args: no script following \"%s\" argument",
+	    TclGetString(objv[i-1])));
     Tcl_SetErrorCode(interp, "TCL", "WRONGARGS", NULL);
     return TCL_ERROR;
 }
@@ -491,7 +494,8 @@ InfoArgsCmd(
     name = TclGetString(objv[1]);
     procPtr = TclFindProc(iPtr, name);
     if (procPtr == NULL) {
-	Tcl_AppendResult(interp, "\"", name, "\" isn't a procedure", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"\"%s\" isn't a procedure", name));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "PROCEDURE", name, NULL);
 	return TCL_ERROR;
     }
@@ -552,7 +556,8 @@ InfoBodyCmd(
     name = TclGetString(objv[1]);
     procPtr = TclFindProc(iPtr, name);
     if (procPtr == NULL) {
-	Tcl_AppendResult(interp, "\"", name, "\" isn't a procedure", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"\"%s\" isn't a procedure", name));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "PROCEDURE", name, NULL);
 	return TCL_ERROR;
     }
@@ -981,7 +986,8 @@ InfoDefaultCmd(
 
     procPtr = TclFindProc(iPtr, procName);
     if (procPtr == NULL) {
-	Tcl_AppendResult(interp, "\"", procName, "\" isn't a procedure",NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"\"%s\" isn't a procedure", procName));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "PROCEDURE", procName,
 		NULL);
 	return TCL_ERROR;
@@ -1012,8 +1018,9 @@ InfoDefaultCmd(
 	}
     }
 
-    Tcl_AppendResult(interp, "procedure \"", procName,
-	    "\" doesn't have an argument \"", argName, "\"", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "procedure \"%s\" doesn't have an argument \"%s\"",
+	    procName, argName));
     Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ARGUMENT", argName, NULL);
     return TCL_ERROR;
 }
@@ -1055,10 +1062,10 @@ InfoErrorStackCmd(
 
     target = interp;
     if (objc == 2) {
-        target = Tcl_GetSlave(interp, Tcl_GetString(objv[1]));
-        if (target == NULL) {
-            return TCL_ERROR;
-        }
+	target = Tcl_GetSlave(interp, Tcl_GetString(objv[1]));
+	if (target == NULL) {
+	    return TCL_ERROR;
+	}
     }
 
     iPtr = (Interp *) target;
@@ -1158,12 +1165,13 @@ InfoFrameCmd(
 	 * A coroutine: must fix the level computations AND the cmdFrame chain,
 	 * which is interrupted at the base.
 	 */
+
 	CmdFrame *lastPtr = NULL;
 
-        runPtr = iPtr->cmdFramePtr;
+	runPtr = iPtr->cmdFramePtr;
 
 	/* TODO - deal with overflow */
-        topLevel += corPtr->caller.cmdFramePtr->level;
+	topLevel += corPtr->caller.cmdFramePtr->level;
 	while (runPtr) {
 	    runPtr->level += corPtr->caller.cmdFramePtr->level;
 	    lastPtr = runPtr;
@@ -1196,8 +1204,8 @@ InfoFrameCmd(
 
     if ((level > topLevel) || (level <= - topLevel)) {
     levelError:
-	Tcl_AppendResult(interp, "bad level \"", TclGetString(objv[1]), "\"",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"bad level \"%s\"", TclGetString(objv[1])));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "STACK_FRAME",
 		TclGetString(objv[1]), NULL);
 	code = TCL_ERROR;
@@ -1401,15 +1409,15 @@ TclInfoFrame(
 	Tcl_HashEntry *namePtr = procPtr->cmdPtr->hPtr;
 
 	if (namePtr) {
-            Tcl_Obj *procNameObj;
+	    Tcl_Obj *procNameObj;
 
 	    /*
 	     * This is a regular command.
 	     */
 
-            TclNewObj(procNameObj);
-            Tcl_GetCommandFullName(interp, (Tcl_Command) procPtr->cmdPtr,
-                    procNameObj);
+	    TclNewObj(procNameObj);
+	    Tcl_GetCommandFullName(interp, (Tcl_Command) procPtr->cmdPtr,
+		    procNameObj);
 	    ADD_PAIR("proc", procNameObj);
 	} else if (procPtr->cmdPtr->clientData) {
 	    ExtraFrameInfo *efiPtr = procPtr->cmdPtr->clientData;
@@ -1538,7 +1546,9 @@ InfoHostnameCmd(
 	Tcl_SetObjResult(interp, Tcl_NewStringObj(name, -1));
 	return TCL_OK;
     }
-    Tcl_SetResult(interp, "unable to determine name of host", TCL_STATIC);
+
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+	    "unable to determine name of host", -1));
     Tcl_SetErrorCode(interp, "TCL", "OPERATION", "HOSTNAME", "UNKNOWN", NULL);
     return TCL_ERROR;
 }
@@ -1609,8 +1619,8 @@ InfoLevelCmd(
     return TCL_ERROR;
 
   levelError:
-    Tcl_AppendResult(interp, "bad level \"", TclGetString(objv[1]), "\"",
-	    NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "bad level \"%s\"", TclGetString(objv[1])));
     Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "STACK_LEVEL",
 	    TclGetString(objv[1]), NULL);
     return TCL_ERROR;
@@ -1656,7 +1666,9 @@ InfoLibraryCmd(
 	Tcl_SetObjResult(interp, Tcl_NewStringObj(libDirName, -1));
 	return TCL_OK;
     }
-    Tcl_SetResult(interp, "no library has been specified for Tcl",TCL_STATIC);
+
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+	    "no library has been specified for Tcl", -1));
     Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "VARIABLE", "tcl_library",NULL);
     return TCL_ERROR;
 }
@@ -2590,9 +2602,10 @@ Tcl_LrepeatObjCmd(
 	return TCL_ERROR;
     }
     if (elementCount < 0) {
-	Tcl_SetObjResult(interp, Tcl_Format(NULL,
-		"bad count \"%d\": must be integer >= 0", 1, objv+1));
-        Tcl_SetErrorCode(interp, "TCL","OPERATION","LREPEAT","NEGARG", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"bad count \"%d\": must be integer >= 0", elementCount));
+	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LREPEAT", "NEGARG",
+		NULL);
 	return TCL_ERROR;
     }
 
@@ -2608,7 +2621,7 @@ Tcl_LrepeatObjCmd(
     if (elementCount && objc > LIST_MAX/elementCount) {
 	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
 		"max length of a Tcl list (%d elements) exceeded", LIST_MAX));
-        Tcl_SetErrorCode(interp, "TCL", "MEMORY", NULL);
+	Tcl_SetErrorCode(interp, "TCL", "MEMORY", NULL);
 	return TCL_ERROR;
     }
     totalElems = objc * elementCount;
@@ -2723,9 +2736,10 @@ Tcl_LreplaceObjCmd(
      */
 
     if ((first >= listLen) && (listLen > 0)) {
-	Tcl_AppendResult(interp, "list doesn't contain element ",
-		TclGetString(objv[2]), NULL);
-        Tcl_SetErrorCode(interp, "TCL","OPERATION","LREPLACE","BADIDX", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"list doesn't contain element %s", TclGetString(objv[2])));
+	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LREPLACE", "BADIDX",
+		NULL);
 	return TCL_ERROR;
     }
     if (last >= listLen) {
@@ -2996,8 +3010,9 @@ Tcl_LsearchObjCmd(
 		Tcl_DecrRefCount(startPtr);
 	    }
 	    if (i > objc-4) {
-		Tcl_AppendResult(interp, "missing starting index", NULL);
-                Tcl_SetErrorCode(interp, "TCL", "ARGUMENT", "MISSING", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"missing starting index", -1));
+		Tcl_SetErrorCode(interp, "TCL", "ARGUMENT", "MISSING", NULL);
 		result = TCL_ERROR;
 		goto done;
 	    }
@@ -3027,10 +3042,10 @@ Tcl_LsearchObjCmd(
 		if (startPtr != NULL) {
 		    Tcl_DecrRefCount(startPtr);
 		}
-		Tcl_AppendResult(interp,
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			"\"-index\" option must be followed by list index",
-			NULL);
-                Tcl_SetErrorCode(interp, "TCL", "ARGUMENT", "MISSING", NULL);
+			-1));
+		Tcl_SetErrorCode(interp, "TCL", "ARGUMENT", "MISSING", NULL);
 		return TCL_ERROR;
 	    }
 
@@ -3088,18 +3103,18 @@ Tcl_LsearchObjCmd(
 	if (startPtr != NULL) {
 	    Tcl_DecrRefCount(startPtr);
 	}
-	Tcl_AppendResult(interp,
-		"-subindices cannot be used without -index option", NULL);
-        Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LSEARCH",
-                "BAD_OPTION_MIX", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"-subindices cannot be used without -index option", -1));
+	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LSEARCH",
+		"BAD_OPTION_MIX", NULL);
 	return TCL_ERROR;
     }
 
     if (bisect && (allMatches || negatedMatch)) {
-	Tcl_AppendResult(interp,
-		"-bisect is not compatible with -all or -not", NULL);
-        Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LSEARCH",
-                "BAD_OPTION_MIX", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"-bisect is not compatible with -all or -not", -1));
+	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LSEARCH",
+		"BAD_OPTION_MIX", NULL);
 	return TCL_ERROR;
     }
 
@@ -3531,7 +3546,7 @@ Tcl_LsetObjCmd(
 
     if (objc < 3) {
 	Tcl_WrongNumArgs(interp, 1, objv,
-                "listVar ?index? ?index ...? value");
+		"listVar ?index? ?index ...? value");
 	return TCL_ERROR;
     }
 
@@ -3664,10 +3679,10 @@ Tcl_LsortObjCmd(
 	    break;
 	case LSORT_COMMAND:
 	    if (i == objc-2) {
-		Tcl_AppendResult(interp,
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			"\"-command\" option must be followed "
-			"by comparison command", NULL);
-                Tcl_SetErrorCode(interp, "TCL", "ARGUMENT", "MISSING", NULL);
+			"by comparison command", -1));
+		Tcl_SetErrorCode(interp, "TCL", "ARGUMENT", "MISSING", NULL);
 		sortInfo.resultCode = TCL_ERROR;
 		goto done2;
 	    }
@@ -3685,29 +3700,30 @@ Tcl_LsortObjCmd(
 	    sortInfo.isIncreasing = 1;
 	    break;
 	case LSORT_INDEX: {
-            int indexc, dummy;
+	    int indexc, dummy;
 	    Tcl_Obj **indexv;
 
 	    if (i == objc-2) {
-		Tcl_AppendResult(interp, "\"-index\" option must be "
-			"followed by list index", NULL);
-                Tcl_SetErrorCode(interp, "TCL", "ARGUMENT", "MISSING", NULL);
-                sortInfo.resultCode = TCL_ERROR;
-                goto done2;
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"\"-index\" option must be followed by list index",
+			-1));
+		Tcl_SetErrorCode(interp, "TCL", "ARGUMENT", "MISSING", NULL);
+		sortInfo.resultCode = TCL_ERROR;
+		goto done2;
 	    }
 	    if (TclListObjGetElements(interp, objv[i+1], &indexc,
 		    &indexv) != TCL_OK) {
-                sortInfo.resultCode = TCL_ERROR;
-                goto done2;
+		sortInfo.resultCode = TCL_ERROR;
+		goto done2;
 	    }
 
-            /*
-             * Check each of the indices for syntactic correctness. Note that
-             * we do not store the converted values here because we do not
-             * know if this is the only -index option yet and so we can't
-             * allocate any space; that happens after the scan through all the
-             * options is done.
-             */
+	    /*
+	     * Check each of the indices for syntactic correctness. Note that
+	     * we do not store the converted values here because we do not
+	     * know if this is the only -index option yet and so we can't
+	     * allocate any space; that happens after the scan through all the
+	     * options is done.
+	     */
 
 	    for (j=0 ; j<indexc ; j++) {
 		if (TclGetIntForIndexM(interp, indexv[j], SORTIDX_END,
@@ -3719,7 +3735,7 @@ Tcl_LsortObjCmd(
 		}
 	    }
 	    indexPtr = objv[i+1];
-            i++;
+	    i++;
 	    break;
 	}
 	case LSORT_INTEGER:
@@ -3739,9 +3755,10 @@ Tcl_LsortObjCmd(
 	    break;
 	case LSORT_STRIDE:
 	    if (i == objc-2) {
-		Tcl_AppendResult(interp, "\"-stride\" option must be ",
-			"followed by stride length", NULL);
-                Tcl_SetErrorCode(interp, "TCL", "ARGUMENT", "MISSING", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"\"-stride\" option must be "
+			"followed by stride length", -1));
+		Tcl_SetErrorCode(interp, "TCL", "ARGUMENT", "MISSING", NULL);
 		sortInfo.resultCode = TCL_ERROR;
 		goto done2;
 	    }
@@ -3750,10 +3767,10 @@ Tcl_LsortObjCmd(
 		goto done2;
 	    }
 	    if (groupSize < 2) {
-		Tcl_AppendResult(interp, "stride length must be at least 2",
-			NULL);
-                Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LSORT",
-                        "BADSTRIDE", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"stride length must be at least 2", -1));
+		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LSORT",
+			"BADSTRIDE", NULL);
 		sortInfo.resultCode = TCL_ERROR;
 		goto done2;
 	    }
@@ -3773,26 +3790,26 @@ Tcl_LsortObjCmd(
      */
 
     if (indexPtr) {
-        Tcl_Obj **indexv;
-
-        TclListObjGetElements(interp, indexPtr, &sortInfo.indexc, &indexv);
-        switch (sortInfo.indexc) {
-        case 0:
-            sortInfo.indexv = NULL;
-            break;
-        case 1:
-            sortInfo.indexv = &sortInfo.singleIndex;
-            break;
-        default:
-            sortInfo.indexv =
+	Tcl_Obj **indexv;
+
+	TclListObjGetElements(interp, indexPtr, &sortInfo.indexc, &indexv);
+	switch (sortInfo.indexc) {
+	case 0:
+	    sortInfo.indexv = NULL;
+	    break;
+	case 1:
+	    sortInfo.indexv = &sortInfo.singleIndex;
+	    break;
+	default:
+	    sortInfo.indexv =
 		    TclStackAlloc(interp, sizeof(int) * sortInfo.indexc);
-            allocatedIndexVector = 1;	/* Cannot use indexc field, as it
-                                         * might be decreased by 1 later. */
-        }
-        for (j=0 ; j<sortInfo.indexc ; j++) {
-            TclGetIntForIndexM(interp, indexv[j], SORTIDX_END,
+	    allocatedIndexVector = 1;	/* Cannot use indexc field, as it
+					 * might be decreased by 1 later. */
+	}
+	for (j=0 ; j<sortInfo.indexc ; j++) {
+	    TclGetIntForIndexM(interp, indexv[j], SORTIDX_END,
 		    &sortInfo.indexv[j]);
-        }
+	}
     }
 
     listObj = objv[objc-1];
@@ -3847,11 +3864,11 @@ Tcl_LsortObjCmd(
 
     if (group) {
 	if (length % groupSize) {
-	    Tcl_AppendResult(interp,
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "list size must be a multiple of the stride length",
+		    -1));
+	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LSORT", "BADSTRIDE",
 		    NULL);
-            Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LSORT", "BADSTRIDE",
-                    NULL);
 	    sortInfo.resultCode = TCL_ERROR;
 	    goto done;
 	}
@@ -3867,11 +3884,11 @@ Tcl_LsortObjCmd(
 		groupOffset = (groupOffset - SORTIDX_END) + groupSize - 1;
 	    }
 	    if (groupOffset < 0 || groupOffset >= groupSize) {
-		Tcl_AppendResult(interp, "when used with \"-stride\", the "
-			"leading \"-index\" value must be within the group",
-			NULL);
-                Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LSORT",
-                        "BADINDEX", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"when used with \"-stride\", the leading \"-index\""
+			" value must be within the group", -1));
+		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LSORT",
+			"BADINDEX", NULL);
 		sortInfo.resultCode = TCL_ERROR;
 		goto done;
 	    }
@@ -4255,11 +4272,10 @@ SortCompare(
 
 	if (TclGetIntFromObj(infoPtr->interp,
 		Tcl_GetObjResult(infoPtr->interp), &order) != TCL_OK) {
-	    Tcl_ResetResult(infoPtr->interp);
-	    Tcl_AppendResult(infoPtr->interp,
-		    "-compare command returned non-integer result", NULL);
-            Tcl_SetErrorCode(infoPtr->interp, "TCL", "OPERATION", "LSORT",
-                    "COMPARISONFAILED", NULL);
+	    Tcl_SetObjResult(infoPtr->interp, Tcl_NewStringObj(
+		    "-compare command returned non-integer result", -1));
+	    Tcl_SetErrorCode(infoPtr->interp, "TCL", "OPERATION", "LSORT",
+		    "COMPARISONFAILED", NULL);
 	    infoPtr->resultCode = TCL_ERROR;
 	    return 0;
 	}
@@ -4470,11 +4486,11 @@ SelectObjFromSublist(
 	    return NULL;
 	}
 	if (currentObj == NULL) {
-            Tcl_SetObjResult(infoPtr->interp, Tcl_ObjPrintf(
-                    "element %d missing from sublist \"%s\"",
-                    index, TclGetString(objPtr)));
-            Tcl_SetErrorCode(infoPtr->interp, "TCL", "OPERATION", "LSORT",
-                    "INDEXFAILED", NULL);
+	    Tcl_SetObjResult(infoPtr->interp, Tcl_ObjPrintf(
+		    "element %d missing from sublist \"%s\"",
+		    index, TclGetString(objPtr)));
+	    Tcl_SetErrorCode(infoPtr->interp, "TCL", "OPERATION", "LSORT",
+		    "INDEXFAILED", NULL);
 	    infoPtr->resultCode = TCL_ERROR;
 	    return NULL;
 	}
@@ -4489,6 +4505,5 @@ SelectObjFromSublist(
  * c-basic-offset: 4
  * fill-column: 78
  * tab-width: 8
- * indent-tabs-mode: nil
  * End:
  */
diff --git a/generic/tclCmdMZ.c b/generic/tclCmdMZ.c
index 7e94d9f..9e720ea 100644
--- a/generic/tclCmdMZ.c
+++ b/generic/tclCmdMZ.c
@@ -204,8 +204,8 @@ Tcl_RegexpObjCmd(
      */
 
     if (doinline && ((objc - 2) != 0)) {
-	Tcl_AppendResult(interp, "regexp match variables not allowed"
-		" when using -inline", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"regexp match variables not allowed when using -inline", -1));
 	goto optionError;
     }
 
@@ -1839,8 +1839,8 @@ StringMapCmd(
 		strncmp(string, "-nocase", (size_t) length2) == 0) {
 	    nocase = 1;
 	} else {
-	    Tcl_AppendResult(interp, "bad option \"", string,
-		    "\": must be -nocase", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "bad option \"%s\": must be -nocase", string));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "INDEX", "option",
 		    string, NULL);
 	    return TCL_ERROR;
@@ -2106,8 +2106,8 @@ StringMatchCmd(
 	    strncmp(string, "-nocase", (size_t) length) == 0) {
 	    nocase = TCL_MATCH_NOCASE;
 	} else {
-	    Tcl_AppendResult(interp, "bad option \"", string,
-		    "\": must be -nocase", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "bad option \"%s\": must be -nocase", string));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "INDEX", "option",
 		    string, NULL);
 	    return TCL_ERROR;
@@ -2567,8 +2567,9 @@ StringEqualCmd(
 		return TCL_ERROR;
 	    }
 	} else {
-	    Tcl_AppendResult(interp, "bad option \"", string2,
-		    "\": must be -nocase or -length", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "bad option \"%s\": must be -nocase or -length",
+		    string2));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "INDEX", "option",
 		    string2, NULL);
 	    return TCL_ERROR;
@@ -2716,8 +2717,9 @@ StringCmpCmd(
 		return TCL_ERROR;
 	    }
 	} else {
-	    Tcl_AppendResult(interp, "bad option \"", string2,
-		    "\": must be -nocase or -length", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "bad option \"%s\": must be -nocase or -length",
+		    string2));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "INDEX", "option",
 		    string2, NULL);
 	    return TCL_ERROR;
@@ -3515,9 +3517,9 @@ TclNRSwitchObjCmd(
 		 * Mode already set via -exact, -glob, or -regexp.
 		 */
 
-		Tcl_AppendResult(interp, "bad option \"",
-			TclGetString(objv[i]), "\": ", options[mode],
-			" option already found", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"bad option \"%s\": %s option already found",
+			TclGetString(objv[i]), options[mode]));
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "SWITCH",
 			"DOUBLEOPT", NULL);
 		return TCL_ERROR;
@@ -3534,8 +3536,9 @@ TclNRSwitchObjCmd(
 	case OPT_INDEXV:
 	    i++;
 	    if (i >= objc-2) {
-		Tcl_AppendResult(interp, "missing variable name argument to ",
-			"-indexvar", " option", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"missing variable name argument to %s option",
+			"-indexvar"));
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "SWITCH",
 			"NOVAR", NULL);
 		return TCL_ERROR;
@@ -3546,8 +3549,9 @@ TclNRSwitchObjCmd(
 	case OPT_MATCHV:
 	    i++;
 	    if (i >= objc-2) {
-		Tcl_AppendResult(interp, "missing variable name argument to ",
-			"-matchvar", " option", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"missing variable name argument to %s option",
+			"-matchvar"));
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "SWITCH",
 			"NOVAR", NULL);
 		return TCL_ERROR;
@@ -3565,15 +3569,15 @@ TclNRSwitchObjCmd(
 	return TCL_ERROR;
     }
     if (indexVarObj != NULL && mode != OPT_REGEXP) {
-	Tcl_AppendResult(interp,
-		"-indexvar option requires -regexp option", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"%s option requires -regexp option", "-indexvar"));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "SWITCH",
 		"MODERESTRICTION", NULL);
 	return TCL_ERROR;
     }
     if (matchVarObj != NULL && mode != OPT_REGEXP) {
-	Tcl_AppendResult(interp,
-		"-matchvar option requires -regexp option", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"%s option requires -regexp option", "-matchvar"));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "SWITCH",
 		"MODERESTRICTION", NULL);
 	return TCL_ERROR;
@@ -3622,7 +3626,8 @@ TclNRSwitchObjCmd(
 
     if (objc % 2) {
 	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "extra switch pattern with no body", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"extra switch pattern with no body", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "SWITCH", "BADARM",
 		NULL);
 
@@ -3637,10 +3642,10 @@ TclNRSwitchObjCmd(
 	if (splitObjs) {
 	    for (i=0 ; i<objc ; i+=2) {
 		if (TclGetString(objv[i])[0] == '#') {
-		    Tcl_AppendResult(interp, ", this may be due to a "
-			    "comment incorrectly placed outside of a "
-			    "switch body - see the \"switch\" "
-			    "documentation", NULL);
+		    Tcl_AppendToObj(Tcl_GetObjResult(interp),
+			    ", this may be due to a comment incorrectly"
+			    " placed outside of a switch body - see the"
+			    " \"switch\" documentation", -1);
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "SWITCH",
 			    "BADARM", "COMMENT?", NULL);
 		    break;
@@ -3657,9 +3662,9 @@ TclNRSwitchObjCmd(
      */
 
     if (strcmp(TclGetString(objv[objc-1]), "-") == 0) {
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "no body specified for pattern \"",
-		TclGetString(objv[objc-2]), "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"no body specified for pattern \"%s\"",
+		TclGetString(objv[objc-2])));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "SWITCH", "BADARM",
 		"FALLTHROUGH", NULL);
 	return TCL_ERROR;
@@ -3985,7 +3990,8 @@ Tcl_ThrowObjCmd(
     if (Tcl_ListObjLength(interp, objv[1], &len) != TCL_OK) {
 	return TCL_ERROR;
     } else if (len < 1) {
-	Tcl_AppendResult(interp, "type must be non-empty list", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"type must be non-empty list", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "THROW", "BADEXCEPTION",
 		NULL);
 	return TCL_ERROR;
@@ -4169,15 +4175,16 @@ TclNRTryObjCmd(
 	switch ((enum Handlers) type) {
 	case TryFinally:	/* finally script */
 	    if (i < objc-2) {
-		Tcl_AppendResult(interp, "finally clause must be last", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"finally clause must be last", -1));
 		Tcl_DecrRefCount(handlersObj);
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "TRY", "FINALLY",
 			"NONTERMINAL", NULL);
 		return TCL_ERROR;
 	    } else if (i == objc-1) {
-		Tcl_AppendResult(interp, "wrong # args to finally clause: ",
-			"must be \"", TclGetString(objv[0]),
-			" ... finally script\"", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"wrong # args to finally clause: must be"
+			" \"... finally script\"", -1));
 		Tcl_DecrRefCount(handlersObj);
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "TRY", "FINALLY",
 			"ARGUMENT", NULL);
@@ -4188,15 +4195,16 @@ TclNRTryObjCmd(
 
 	case TryOn:		/* on code variableList script */
 	    if (i > objc-4) {
-		Tcl_AppendResult(interp, "wrong # args to on clause: ",
-			"must be \"", TclGetString(objv[0]),
-			" ... on code variableList script\"", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"wrong # args to on clause: must be \"... on code"
+			" variableList script\"", -1));
 		Tcl_DecrRefCount(handlersObj);
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "TRY", "ON",
 			"ARGUMENT", NULL);
 		return TCL_ERROR;
 	    }
-	    if (TCL_ERROR == TclGetCompletionCodeFromObj(interp, objv[i+1], &code)) {
+	    if (TclGetCompletionCodeFromObj(interp, objv[i+1],
+		    &code) != TCL_OK) {
 		Tcl_DecrRefCount(handlersObj);
 		return TCL_ERROR;
 	    }
@@ -4205,9 +4213,10 @@ TclNRTryObjCmd(
 
 	case TryTrap:		/* trap pattern variableList script */
 	    if (i > objc-4) {
-		Tcl_AppendResult(interp, "wrong # args to trap clause: ",
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"wrong # args to trap clause: "
 			"must be \"... trap pattern variableList script\"",
-			NULL);
+			-1));
 		Tcl_DecrRefCount(handlersObj);
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "TRY", "TRAP",
 			"ARGUMENT", NULL);
@@ -4248,9 +4257,8 @@ TclNRTryObjCmd(
 	}
     }
     if (bodyShared) {
-	Tcl_AppendResult(interp,
-		"last non-finally clause must not have a body of \"-\"",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"last non-finally clause must not have a body of \"-\"", -1));
 	Tcl_DecrRefCount(handlersObj);
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "TRY", "BADFALLTHROUGH",
 		NULL);
diff --git a/generic/tclConfig.c b/generic/tclConfig.c
index dea487a..a4ba71a 100644
--- a/generic/tclConfig.c
+++ b/generic/tclConfig.c
@@ -236,7 +236,7 @@ QueryConfigObjCmd(
 	 * present.
 	 */
 
-	Tcl_SetResult(interp, "package not known", TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj("package not known", -1));
 	Tcl_SetErrorCode(interp, "TCL", "FATAL", "PKGCFG_BASE",
 		Tcl_GetString(pkgName), NULL);
 	return TCL_ERROR;
@@ -251,7 +251,7 @@ QueryConfigObjCmd(
 
 	if (Tcl_DictObjGet(interp, pkgDict, objv[2], &val) != TCL_OK
 		|| val == NULL) {
-	    Tcl_SetResult(interp, "key not known", TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj("key not known", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "CONFIG",
 		    Tcl_GetString(objv[2]), NULL);
 	    return TCL_ERROR;
@@ -270,8 +270,8 @@ QueryConfigObjCmd(
 	listPtr = Tcl_NewListObj(n, NULL);
 
 	if (!listPtr) {
-	    Tcl_SetResult(interp, "insufficient memory to create list",
-		    TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "insufficient memory to create list", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "MEMORY", NULL);
 	    return TCL_ERROR;
 	}
diff --git a/generic/tclDictObj.c b/generic/tclDictObj.c
index ac2cb62..691fab9 100644
--- a/generic/tclDictObj.c
+++ b/generic/tclDictObj.c
@@ -700,7 +700,8 @@ SetDictFromAny(
 
   missingValue:
     if (interp != NULL) {
-	Tcl_SetResult(interp, "missing value to go with key", TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"missing value to go with key", -1));
 	Tcl_SetErrorCode(interp, "TCL", "VALUE", "DICTIONARY", NULL);
     }
     result = TCL_ERROR;
@@ -779,9 +780,9 @@ TclTraceDictPath(
 	    }
 	    if ((flags & DICT_PATH_CREATE) != DICT_PATH_CREATE) {
 		if (interp != NULL) {
-		    Tcl_ResetResult(interp);
-		    Tcl_AppendResult(interp, "key \"", TclGetString(keyv[i]),
-			    "\" not known in dictionary", NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			    "key \"%s\" not known in dictionary",
+			    TclGetString(keyv[i])));
 		    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "DICT",
 			    TclGetString(keyv[i]), NULL);
 		}
@@ -1571,9 +1572,9 @@ DictGetCmd(
 	return result;
     }
     if (valuePtr == NULL) {
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "key \"", TclGetString(objv[objc-1]),
-		"\" not known in dictionary", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"key \"%s\" not known in dictionary",
+		TclGetString(objv[objc-1])));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "DICT",
 		TclGetString(objv[objc-1]), NULL);
 	return TCL_ERROR;
@@ -2027,6 +2028,7 @@ DictInfoCmd(
 {
     Tcl_Obj *dictPtr;
     Dict *dict;
+    char *statsStr;
 
     if (objc != 2) {
 	Tcl_WrongNumArgs(interp, 1, objv, "dictionary");
@@ -2042,7 +2044,9 @@ DictInfoCmd(
     }
     dict = dictPtr->internalRep.otherValuePtr;
 
-    Tcl_SetResult(interp, Tcl_HashStats(&dict->table), TCL_DYNAMIC);
+    statsStr = Tcl_HashStats(&dict->table);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(statsStr, -1));
+    ckfree(statsStr);
     return TCL_OK;
 }
 
@@ -2371,8 +2375,8 @@ DictForNRCmd(
 	return TCL_ERROR;
     }
     if (varc != 2) {
-	Tcl_SetResult(interp, "must have exactly two variable names",
-		TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"must have exactly two variable names", -1));
 	return TCL_ERROR;
     }
     searchPtr = TclStackAlloc(interp, sizeof(Tcl_DictSearch));
@@ -2787,8 +2791,8 @@ DictFilterCmd(
 	    return TCL_ERROR;
 	}
 	if (varc != 2) {
-	    Tcl_SetResult(interp, "must have exactly two variable names",
-		    TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "must have exactly two variable names", -1));
 	    return TCL_ERROR;
 	}
 	keyVarObj = varv[0];
@@ -2828,16 +2832,19 @@ DictFilterCmd(
 	    if (Tcl_ObjSetVar2(interp, keyVarObj, NULL, keyObj,
 		    TCL_LEAVE_ERR_MSG) == NULL) {
 		Tcl_ResetResult(interp);
-		Tcl_AppendResult(interp, "couldn't set key variable: \"",
-			TclGetString(keyVarObj), "\"", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"couldn't set key variable: \"%s\"",
+			TclGetString(keyVarObj)));
 		result = TCL_ERROR;
 		goto abnormalResult;
 	    }
 	    if (Tcl_ObjSetVar2(interp, valueVarObj, NULL, valueObj,
 		    TCL_LEAVE_ERR_MSG) == NULL) {
 		Tcl_ResetResult(interp);
-		Tcl_AppendResult(interp, "couldn't set value variable: \"",
-			TclGetString(valueVarObj), "\"", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"couldn't set value variable: \"%s\"",
+			TclGetString(valueVarObj)));
+		result = TCL_ERROR;
 		goto abnormalResult;
 	    }
 
diff --git a/generic/tclEncoding.c b/generic/tclEncoding.c
index 0fa6661..7a55724 100644
--- a/generic/tclEncoding.c
+++ b/generic/tclEncoding.c
@@ -1542,7 +1542,8 @@ OpenEncodingFileChannel(
     }
 
     if ((NULL == chan) && (interp != NULL)) {
-	Tcl_AppendResult(interp, "unknown encoding \"", name, "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"unknown encoding \"%s\"", name));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ENCODING", name, NULL);
     }
     Tcl_DecrRefCount(fileNameObj);
@@ -1616,7 +1617,8 @@ LoadEncodingFile(
 	break;
     }
     if ((encoding == NULL) && (interp != NULL)) {
-	Tcl_AppendResult(interp, "invalid encoding file \"", name, "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"invalid encoding file \"%s\"", name));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ENCODING", name, NULL);
     }
     Tcl_Close(NULL, chan);
diff --git a/generic/tclEnsemble.c b/generic/tclEnsemble.c
index 754e480..b76c603 100644
--- a/generic/tclEnsemble.c
+++ b/generic/tclEnsemble.c
@@ -17,6 +17,7 @@
  * Declarations for functions local to this file:
  */
 
+static inline Tcl_Obj *	NewNsObj(Tcl_Namespace *namespacePtr);
 static inline int	EnsembleUnknownCallback(Tcl_Interp *interp,
 			    EnsembleConfig *ensemblePtr, int objc,
 			    Tcl_Obj *const objv[], Tcl_Obj **prefixObjPtr);
@@ -78,6 +79,19 @@ const Tcl_ObjType tclEnsembleCmdType = {
     NULL			/* setFromAnyProc */
 };
 
+static inline Tcl_Obj *
+NewNsObj(
+    Tcl_Namespace *namespacePtr)
+{
+    register Namespace *nsPtr = (Namespace *) namespacePtr;
+
+    if (namespacePtr == TclGetGlobalNamespace(nsPtr->interp)) {
+	return Tcl_NewStringObj("::", 2);
+    } else {
+	return Tcl_NewStringObj(nsPtr->fullName, -1);
+    }
+}
+
 /*
  *----------------------------------------------------------------------
  *
@@ -116,9 +130,10 @@ TclNamespaceEnsembleCmd(
 
     if (nsPtr == NULL || nsPtr->flags & NS_DYING) {
 	if (!Tcl_InterpDeleted(interp)) {
-	    Tcl_AppendResult(interp,
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "tried to manipulate ensemble of deleted namespace",
-		    NULL);
+		    -1));
+	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "DEAD", NULL);
 	}
 	return TCL_ERROR;
     }
@@ -235,9 +250,11 @@ TclNamespaceEnsembleCmd(
 			return TCL_ERROR;
 		    }
 		    if (len < 1) {
-			Tcl_SetResult(interp,
+			Tcl_SetObjResult(interp, Tcl_NewStringObj(
 				"ensemble subcommand implementations "
-				"must be non-empty lists", TCL_STATIC);
+				"must be non-empty lists", -1));
+			Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE",
+				"EMPTY_TARGET", NULL);
 			Tcl_DictObjDone(&search);
 			if (patchedDict) {
 			    Tcl_DecrRefCount(patchedDict);
@@ -250,7 +267,7 @@ TclNamespaceEnsembleCmd(
 		    cmd = TclGetString(listv[0]);
 		    if (!(cmd[0] == ':' && cmd[1] == ':')) {
 			Tcl_Obj *newList = Tcl_NewListObj(len, listv);
-			Tcl_Obj *newCmd = Tcl_NewStringObj(nsPtr->fullName,-1);
+			Tcl_Obj *newCmd = NewNsObj((Tcl_Namespace *) nsPtr);
 
 			if (nsPtr->parentPtr) {
 			    Tcl_AppendStringsToObj(newCmd, "::", NULL);
@@ -370,8 +387,7 @@ TclNamespaceEnsembleCmd(
 	    case CONF_NAMESPACE:
 		namespacePtr = NULL;		/* silence gcc 4 warning */
 		Tcl_GetEnsembleNamespace(NULL, token, &namespacePtr);
-		Tcl_SetResult(interp, ((Namespace *) namespacePtr)->fullName,
-			TCL_VOLATILE);
+		Tcl_SetObjResult(interp, NewNsObj(namespacePtr));
 		break;
 	    case CONF_PREFIX: {
 		int flags = 0;			/* silence gcc 4 warning */
@@ -411,9 +427,7 @@ TclNamespaceEnsembleCmd(
 			    -1));
 	    namespacePtr = NULL;		/* silence gcc 4 warning */
 	    Tcl_GetEnsembleNamespace(NULL, token, &namespacePtr);
-	    Tcl_ListObjAppendElement(NULL, resultObj,
-		    Tcl_NewStringObj(((Namespace *) namespacePtr)->fullName,
-			    -1));
+	    Tcl_ListObjAppendElement(NULL, resultObj, NewNsObj(namespacePtr));
 
 	    /* -parameters option */
 	    Tcl_ListObjAppendElement(NULL, resultObj,
@@ -515,9 +529,11 @@ TclNamespaceEnsembleCmd(
 			    goto freeMapAndError;
 			}
 			if (len < 1) {
-			    Tcl_SetResult(interp,
+			    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 				    "ensemble subcommand implementations "
-				    "must be non-empty lists", TCL_STATIC);
+				    "must be non-empty lists", -1));
+			    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE",
+				    "EMPTY_TARGET", NULL);
 			    Tcl_DictObjDone(&search);
 			    if (patchedDict) {
 				Tcl_DecrRefCount(patchedDict);
@@ -527,8 +543,7 @@ TclNamespaceEnsembleCmd(
 			cmd = TclGetString(listv[0]);
 			if (!(cmd[0] == ':' && cmd[1] == ':')) {
 			    Tcl_Obj *newList = Tcl_DuplicateObj(listObj);
-			    Tcl_Obj *newCmd =
-				    Tcl_NewStringObj(nsPtr->fullName, -1);
+			    Tcl_Obj *newCmd = NewNsObj((Tcl_Namespace*)nsPtr);
 
 			    if (nsPtr->parentPtr) {
 				Tcl_AppendStringsToObj(newCmd, "::", NULL);
@@ -554,7 +569,9 @@ TclNamespaceEnsembleCmd(
 		    continue;
 		}
 		case CONF_NAMESPACE:
-		    Tcl_AppendResult(interp, "option -namespace is read-only",
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "option -namespace is read-only", -1));
+		    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "READ_ONLY",
 			    NULL);
 		    goto freeMapAndError;
 		case CONF_PREFIX:
@@ -629,7 +646,7 @@ Tcl_CreateEnsemble(
      */
 
     if (!(name[0] == ':' && name[1] == ':')) {
-	nameObj = Tcl_NewStringObj(nsPtr->fullName, -1);
+	nameObj = NewNsObj((Tcl_Namespace *) nsPtr);
 	if (nsPtr->parentPtr == NULL) {
 	    Tcl_AppendStringsToObj(nameObj, name, NULL);
 	} else {
@@ -702,7 +719,9 @@ Tcl_SetEnsembleSubcommandList(
     Tcl_Obj *oldList;
 
     if (cmdPtr->objProc != NsEnsembleImplementationCmd) {
-	Tcl_AppendResult(interp, "command is not an ensemble", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"command is not an ensemble", -1));
+	Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "NOT_ENSEMBLE", NULL);
 	return TCL_ERROR;
     }
     if (subcmdList != NULL) {
@@ -776,7 +795,9 @@ Tcl_SetEnsembleParameterList(
     int length;
 
     if (cmdPtr->objProc != NsEnsembleImplementationCmd) {
-	Tcl_AppendResult(interp, "command is not an ensemble", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"command is not an ensemble", -1));
+	Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "NOT_ENSEMBLE", NULL);
 	return TCL_ERROR;
     }
     if (paramList == NULL) {
@@ -850,7 +871,9 @@ Tcl_SetEnsembleMappingDict(
     Tcl_Obj *oldDict;
 
     if (cmdPtr->objProc != NsEnsembleImplementationCmd) {
-	Tcl_AppendResult(interp, "command is not an ensemble", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"command is not an ensemble", -1));
+	Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "NOT_ENSEMBLE", NULL);
 	return TCL_ERROR;
     }
     if (mapDict != NULL) {
@@ -873,9 +896,11 @@ Tcl_SetEnsembleMappingDict(
 	    }
 	    bytes = TclGetString(cmdObjPtr);
 	    if (bytes[0] != ':' || bytes[1] != ':') {
-		Tcl_AppendResult(interp,
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			"ensemble target is not a fully-qualified command",
-			NULL);
+			-1));
+		Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE",
+			"UNQUALIFIED_TARGET", NULL);
 		Tcl_DictObjDone(&search);
 		return TCL_ERROR;
 	    }
@@ -945,7 +970,9 @@ Tcl_SetEnsembleUnknownHandler(
     Tcl_Obj *oldList;
 
     if (cmdPtr->objProc != NsEnsembleImplementationCmd) {
-	Tcl_AppendResult(interp, "command is not an ensemble", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"command is not an ensemble", -1));
+	Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "NOT_ENSEMBLE", NULL);
 	return TCL_ERROR;
     }
     if (unknownList != NULL) {
@@ -1009,7 +1036,9 @@ Tcl_SetEnsembleFlags(
     int wasCompiled;
 
     if (cmdPtr->objProc != NsEnsembleImplementationCmd) {
-	Tcl_AppendResult(interp, "command is not an ensemble", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"command is not an ensemble", -1));
+	Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "NOT_ENSEMBLE", NULL);
 	return TCL_ERROR;
     }
 
@@ -1084,7 +1113,9 @@ Tcl_GetEnsembleSubcommandList(
 
     if (cmdPtr->objProc != NsEnsembleImplementationCmd) {
 	if (interp != NULL) {
-	    Tcl_AppendResult(interp, "command is not an ensemble", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "command is not an ensemble", -1));
+	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "NOT_ENSEMBLE", NULL);
 	}
 	return TCL_ERROR;
     }
@@ -1124,7 +1155,9 @@ Tcl_GetEnsembleParameterList(
 
     if (cmdPtr->objProc != NsEnsembleImplementationCmd) {
 	if (interp != NULL) {
-	    Tcl_AppendResult(interp, "command is not an ensemble", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "command is not an ensemble", -1));
+	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "NOT_ENSEMBLE", NULL);
 	}
 	return TCL_ERROR;
     }
@@ -1164,7 +1197,9 @@ Tcl_GetEnsembleMappingDict(
 
     if (cmdPtr->objProc != NsEnsembleImplementationCmd) {
 	if (interp != NULL) {
-	    Tcl_AppendResult(interp, "command is not an ensemble", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "command is not an ensemble", -1));
+	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "NOT_ENSEMBLE", NULL);
 	}
 	return TCL_ERROR;
     }
@@ -1203,7 +1238,9 @@ Tcl_GetEnsembleUnknownHandler(
 
     if (cmdPtr->objProc != NsEnsembleImplementationCmd) {
 	if (interp != NULL) {
-	    Tcl_AppendResult(interp, "command is not an ensemble", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "command is not an ensemble", -1));
+	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "NOT_ENSEMBLE", NULL);
 	}
 	return TCL_ERROR;
     }
@@ -1242,7 +1279,9 @@ Tcl_GetEnsembleFlags(
 
     if (cmdPtr->objProc != NsEnsembleImplementationCmd) {
 	if (interp != NULL) {
-	    Tcl_AppendResult(interp, "command is not an ensemble", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "command is not an ensemble", -1));
+	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "NOT_ENSEMBLE", NULL);
 	}
 	return TCL_ERROR;
     }
@@ -1281,7 +1320,9 @@ Tcl_GetEnsembleNamespace(
 
     if (cmdPtr->objProc != NsEnsembleImplementationCmd) {
 	if (interp != NULL) {
-	    Tcl_AppendResult(interp, "command is not an ensemble", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "command is not an ensemble", -1));
+	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "NOT_ENSEMBLE", NULL);
 	}
 	return TCL_ERROR;
     }
@@ -1337,8 +1378,9 @@ Tcl_FindEnsemble(
 
 	if (cmdPtr == NULL || cmdPtr->objProc != NsEnsembleImplementationCmd){
 	    if (flags & TCL_LEAVE_ERR_MSG) {
-		Tcl_AppendResult(interp, "\"", TclGetString(cmdNameObj),
-			"\" is not an ensemble command", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"\"%s\" is not an ensemble command",
+			TclGetString(cmdNameObj)));
 		Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ENSEMBLE",
 			TclGetString(cmdNameObj), NULL);
 	    }
@@ -1591,6 +1633,7 @@ NsEnsembleImplementationCmdNR(
 				 * specified but not yet cached command
 				 * names. */
     int reparseCount = 0;	/* Number of reparses. */
+    Tcl_Obj *errorObj;		/* Used for building error messages. */
 
     /*
      * Must recheck objc, since numParameters might have changed. Cf. test
@@ -1631,8 +1674,9 @@ NsEnsembleImplementationCmdNR(
 	 */
 
 	if (!Tcl_InterpDeleted(interp)) {
-	    Tcl_AppendResult(interp,
-		    "ensemble activated for deleted namespace", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "ensemble activated for deleted namespace", -1));
+	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "DEAD", NULL);
 	}
 	return TCL_ERROR;
     }
@@ -1880,35 +1924,34 @@ NsEnsembleImplementationCmdNR(
      */
 
     Tcl_ResetResult(interp);
-    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ENSEMBLE",
+    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "SUBCOMMAND",
 	    TclGetString(objv[1+ensemblePtr->numParameters]), NULL);
     if (ensemblePtr->subcommandTable.numEntries == 0) {
-	Tcl_AppendResult(interp, "unknown subcommand \"",
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"unknown subcommand \"%s\": namespace %s does not"
+		" export any commands",
 		TclGetString(objv[1+ensemblePtr->numParameters]),
-		"\": namespace ", ensemblePtr->nsPtr->fullName,
-		" does not export any commands", NULL);
+		ensemblePtr->nsPtr->fullName));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "SUBCOMMAND",
 		TclGetString(objv[1+ensemblePtr->numParameters]), NULL);
 	return TCL_ERROR;
     }
-    Tcl_AppendResult(interp, "unknown ",
-	    (ensemblePtr->flags & TCL_ENSEMBLE_PREFIX ? "or ambiguous " : ""),
-	    "subcommand \"", TclGetString(objv[1+ensemblePtr->numParameters]),
-	    "\": must be ", NULL);
+    errorObj = Tcl_ObjPrintf("unknown%s subcommand \"%s\": must be ",
+	    (ensemblePtr->flags & TCL_ENSEMBLE_PREFIX ? " or ambiguous" : ""),
+	    TclGetString(objv[1+ensemblePtr->numParameters]));
     if (ensemblePtr->subcommandTable.numEntries == 1) {
-	Tcl_AppendResult(interp, ensemblePtr->subcommandArrayPtr[0], NULL);
+	Tcl_AppendToObj(errorObj, ensemblePtr->subcommandArrayPtr[0], -1);
     } else {
 	int i;
 
 	for (i=0 ; i<ensemblePtr->subcommandTable.numEntries-1 ; i++) {
-	    Tcl_AppendResult(interp,
-		    ensemblePtr->subcommandArrayPtr[i], ", ", NULL);
+	    Tcl_AppendToObj(errorObj, ensemblePtr->subcommandArrayPtr[i], -1);
+	    Tcl_AppendToObj(errorObj, ", ", 2);
 	}
-	Tcl_AppendResult(interp, "or ",
-		ensemblePtr->subcommandArrayPtr[i], NULL);
+	Tcl_AppendPrintfToObj(errorObj, "or %s",
+		ensemblePtr->subcommandArrayPtr[i]);
     }
-    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "SUBCOMMAND",
-	    TclGetString(objv[1+ensemblePtr->numParameters]), NULL);
+    Tcl_SetObjResult(interp, errorObj);
     return TCL_ERROR;
 }
 
@@ -2034,7 +2077,6 @@ EnsembleUnknownCallback(
 {
     int paramc, i, result, prefixObjc;
     Tcl_Obj **paramv, *unknownCmd, *ensObj;
-    char buf[TCL_INTEGER_SPACE];
 
     /*
      * Create the unknown command callback to determine what to do.
@@ -2061,9 +2103,12 @@ EnsembleUnknownCallback(
     ((Interp *) interp)->evalFlags |= TCL_EVAL_REDIRECT;
     result = Tcl_EvalObjv(interp, paramc, paramv, 0);
     if ((result == TCL_OK) && (ensemblePtr->flags & ENSEMBLE_DEAD)) {
-	Tcl_SetResult(interp,
-		"unknown subcommand handler deleted its ensemble",
-		TCL_STATIC);
+	if (!Tcl_InterpDeleted(interp)) {
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "unknown subcommand handler deleted its ensemble", -1));
+	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "UNKNOWN_DELETED",
+		    NULL);
+	}
 	result = TCL_ERROR;
     }
     Tcl_Release(ensemblePtr);
@@ -2112,26 +2157,26 @@ EnsembleUnknownCallback(
     if (!Tcl_InterpDeleted(interp)) {
 	if (result != TCL_ERROR) {
 	    Tcl_ResetResult(interp);
-	    Tcl_SetResult(interp,
-		    "unknown subcommand handler returned bad code: ",
-		    TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "unknown subcommand handler returned bad code: ", -1));
 	    switch (result) {
 	    case TCL_RETURN:
-		Tcl_AppendResult(interp, "return", NULL);
+		Tcl_AppendToObj(Tcl_GetObjResult(interp), "return", -1);
 		break;
 	    case TCL_BREAK:
-		Tcl_AppendResult(interp, "break", NULL);
+		Tcl_AppendToObj(Tcl_GetObjResult(interp), "break", -1);
 		break;
 	    case TCL_CONTINUE:
-		Tcl_AppendResult(interp, "continue", NULL);
+		Tcl_AppendToObj(Tcl_GetObjResult(interp), "continue", -1);
 		break;
 	    default:
-		sprintf(buf, "%d", result);
-		Tcl_AppendResult(interp, buf, NULL);
+		Tcl_AppendPrintfToObj(Tcl_GetObjResult(interp), "%d", result);
 	    }
 	    Tcl_AddErrorInfo(interp, "\n    result of "
 		    "ensemble unknown subcommand handler: ");
 	    Tcl_AddErrorInfo(interp, TclGetString(unknownCmd));
+	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "UNKNOWN_RESULT",
+		    NULL);
 	} else {
 	    Tcl_AddErrorInfo(interp,
 		    "\n    (ensemble unknown subcommand handler)");
@@ -2392,7 +2437,7 @@ BuildEnsembleConfig(
 	     * the programmer's responsibility (or [::unknown] of course).
 	     */
 
-	    cmdObj = Tcl_NewStringObj(ensemblePtr->nsPtr->fullName, -1);
+	    cmdObj = NewNsObj((Tcl_Namespace *) ensemblePtr->nsPtr);
 	    if (ensemblePtr->nsPtr->parentPtr != NULL) {
 		Tcl_AppendStringsToObj(cmdObj, "::", name, NULL);
 	    } else {
diff --git a/generic/tclEvent.c b/generic/tclEvent.c
index e65862c..0b585b6 100644
--- a/generic/tclEvent.c
+++ b/generic/tclEvent.c
@@ -1416,7 +1416,7 @@ Tcl_VwaitObjCmd(
 	}
 	if (Tcl_LimitExceeded(interp)) {
 	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "limit exceeded", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj("limit exceeded", -1));
 	    break;
 	}
     }
@@ -1426,8 +1426,9 @@ Tcl_VwaitObjCmd(
 
     if (!foundEvent) {
 	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "can't wait for variable \"", nameString,
-		"\": would wait forever", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"can't wait for variable \"%s\": would wait forever",
+		nameString));
 	Tcl_SetErrorCode(interp, "TCL", "EVENT", "NO_SOURCES", NULL);
 	return TCL_ERROR;
     }
@@ -1519,7 +1520,7 @@ Tcl_UpdateObjCmd(
 	}
 	if (Tcl_LimitExceeded(interp)) {
 	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "limit exceeded", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj("limit exceeded", -1));
 	    return TCL_ERROR;
 	}
     }
diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index e402634..3c0b472 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.c
@@ -4896,8 +4896,8 @@ TEBCresume(
 
 	    case INST_RSHIFT:
 		if (l2 < 0) {
-		    Tcl_SetResult(interp, "negative shift argument",
-			    TCL_STATIC);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "negative shift argument", -1));
 #if 0
 		    DECACHE_STACK_INFO();
 		    Tcl_SetErrorCode(interp, "ARITH", "DOMAIN",
@@ -4944,8 +4944,8 @@ TEBCresume(
 
 	    case INST_LSHIFT:
 		if (l2 < 0) {
-		    Tcl_SetResult(interp, "negative shift argument",
-			    TCL_STATIC);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "negative shift argument", -1));
 #if 0
 		    DECACHE_STACK_INFO();
 		    Tcl_SetErrorCode(interp, "ARITH", "DOMAIN",
@@ -4967,9 +4967,8 @@ TEBCresume(
 		     * good place to draw the line.
 		     */
 
-		    Tcl_SetResult(interp,
-			    "integer value too large to represent",
-			    TCL_STATIC);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "integer value too large to represent", -1));
 #if 0
 		    DECACHE_STACK_INFO();
 		    Tcl_SetErrorCode(interp, "ARITH", "IOVERFLOW",
@@ -5671,9 +5670,9 @@ TEBCresume(
 		NEXT_INST_V(5, opnd+1, 1);
 	    }
 	    DECACHE_STACK_INFO();
-	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "key \"", TclGetString(OBJ_AT_TOS),
-		    "\" not known in dictionary", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "key \"%s\" not known in dictionary",
+		    TclGetString(OBJ_AT_TOS)));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "DICT",
 		    TclGetString(OBJ_AT_TOS), NULL);
 	    CACHE_STACK_INFO();
@@ -6304,7 +6303,7 @@ TEBCresume(
 
     divideByZero:
 	DECACHE_STACK_INFO();
-	Tcl_SetResult(interp, "divide by zero", TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj("divide by zero", -1));
 	Tcl_SetErrorCode(interp, "ARITH", "DIVZERO", "divide by zero", NULL);
 	CACHE_STACK_INFO();
 	goto gotError;
@@ -6316,8 +6315,8 @@ TEBCresume(
 
     exponOfZero:
 	DECACHE_STACK_INFO();
-	Tcl_SetResult(interp, "exponentiation of zero by negative power",
-		TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"exponentiation of zero by negative power", -1));
 	Tcl_SetErrorCode(interp, "ARITH", "DOMAIN",
 		"exponentiation of zero by negative power", NULL);
 	CACHE_STACK_INFO();
@@ -6693,7 +6692,8 @@ ExecuteExtendedBinaryMathOp(
 	    invalid = 0;
 	}
 	if (invalid) {
-	    Tcl_SetResult(interp, "negative shift argument", TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "negative shift argument", -1));
 	    return GENERAL_ARITHMETIC_ERROR;
 	}
 
@@ -6723,8 +6723,8 @@ ExecuteExtendedBinaryMathOp(
 		 * place to draw the line.
 		 */
 
-		Tcl_SetResult(interp, "integer value too large to represent",
-			TCL_STATIC);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"integer value too large to represent", -1));
 		return GENERAL_ARITHMETIC_ERROR;
 	    }
 	    shift = (int)(*((const long *)ptr2));
@@ -7125,7 +7125,8 @@ ExecuteExtendedBinaryMathOp(
 	 */
 
 	if (type2 != TCL_NUMBER_LONG) {
-	    Tcl_SetResult(interp, "exponent too large", TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "exponent too large", -1));
 	    return GENERAL_ARITHMETIC_ERROR;
 	}
 
@@ -7363,7 +7364,8 @@ ExecuteExtendedBinaryMathOp(
 	Tcl_TakeBignumFromObj(NULL, value2Ptr, &big2);
 	if (big2.used > 1) {
 	    mp_clear(&big2);
-	    Tcl_SetResult(interp, "exponent too large", TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "exponent too large", -1));
 	    return GENERAL_ARITHMETIC_ERROR;
 	}
 	Tcl_TakeBignumFromObj(NULL, valuePtr, &big1);
diff --git a/generic/tclFCmd.c b/generic/tclFCmd.c
index a868fe3..6611480 100644
--- a/generic/tclFCmd.c
+++ b/generic/tclFCmd.c
@@ -11,7 +11,7 @@
  */
 
 #ifndef _WIN64
-/* See [Bug 2935503]: file mtime sets wrong time */
+/* See [Bug 3354324]: file mtime sets wrong time */
 #   define _USE_32BIT_TIME_T
 #endif
 
@@ -152,9 +152,9 @@ FileCopyRename(
 	if ((objc - i) > 2) {
 	    errno = ENOTDIR;
 	    Tcl_PosixError(interp);
-	    Tcl_AppendResult(interp, "error ",
-		    (copyFlag ? "copying" : "renaming"), ": target \"",
-		    TclGetString(target), "\" is not a directory", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "error %s: target \"%s\" is not a directory",
+		    (copyFlag?"copying":"renaming"), TclGetString(target)));
 	    result = TCL_ERROR;
 	} else {
 	    /*
@@ -304,8 +304,9 @@ TclFileMakeDirsCmd(
 
   done:
     if (errfile != NULL) {
-	Tcl_AppendResult(interp, "can't create directory \"",
-		TclGetString(errfile), "\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"can't create directory \"%s\": %s",
+		TclGetString(errfile), Tcl_PosixError(interp)));
 	result = TCL_ERROR;
     }
     if (split != NULL) {
@@ -384,9 +385,9 @@ TclFileDeleteCmd(
 	    result = Tcl_FSRemoveDirectory(objv[i], force, &errorBuffer);
 	    if (result != TCL_OK) {
 		if ((force == 0) && (errno == EEXIST)) {
-		    Tcl_AppendResult(interp, "error deleting \"",
-			    TclGetString(objv[i]), "\": directory not empty",
-			    NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			    "error deleting \"%s\": directory not empty",
+			    TclGetString(objv[i])));
 		    Tcl_PosixError(interp);
 		    goto done;
 		}
@@ -426,12 +427,13 @@ TclFileDeleteCmd(
 	     * We try to accomodate poor error results from our Tcl_FS calls.
 	     */
 
-	    Tcl_AppendResult(interp, "error deleting unknown file: ",
-		    Tcl_PosixError(interp), NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "error deleting unknown file: %s",
+		    Tcl_PosixError(interp)));
 	} else {
-	    Tcl_AppendResult(interp, "error deleting \"",
-		    TclGetString(errfile), "\": ", Tcl_PosixError(interp),
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "error deleting \"%s\": %s",
+		    TclGetString(errfile), Tcl_PosixError(interp)));
 	}
     }
 
@@ -540,17 +542,17 @@ CopyRenameOneFile(
 	if (S_ISDIR(sourceStatBuf.st_mode)
 		&& !S_ISDIR(targetStatBuf.st_mode)) {
 	    errno = EISDIR;
-	    Tcl_AppendResult(interp, "can't overwrite file \"",
-		    TclGetString(target), "\" with directory \"",
-		    TclGetString(source), "\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "can't overwrite file \"%s\" with directory \"%s\"",
+		    TclGetString(target), TclGetString(source)));
 	    goto done;
 	}
 	if (!S_ISDIR(sourceStatBuf.st_mode)
 		&& S_ISDIR(targetStatBuf.st_mode)) {
 	    errno = EISDIR;
-	    Tcl_AppendResult(interp, "can't overwrite directory \"",
-		    TclGetString(target), "\" with file \"",
-		    TclGetString(source), "\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "can't overwrite directory \"%s\" with file \"%s\"",
+		    TclGetString(target), TclGetString(source)));
 	    goto done;
 	}
 
@@ -581,10 +583,10 @@ CopyRenameOneFile(
 	}
 
 	if (errno == EINVAL) {
-	    Tcl_AppendResult(interp, "error renaming \"",
-		    TclGetString(source), "\" to \"", TclGetString(target),
-		    "\": trying to rename a volume or "
-		    "move a directory into itself", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "error renaming \"%s\" to \"%s\": trying to rename a"
+		    " volume or move a directory into itself",
+		    TclGetString(source), TclGetString(target)));
 	    goto done;
 	} else if (errno != EXDEV) {
 	    errfile = target;
@@ -628,8 +630,9 @@ CopyRenameOneFile(
 	     * Actual file doesn't exist.
 	     */
 
-	    Tcl_AppendResult(interp, "error copying \"", TclGetString(source),
-		    "\": the target of this link doesn't exist", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "error copying \"%s\": the target of this link doesn't"
+		    " exist", TclGetString(source)));
 	    goto done;
 	} else {
 	    int counter = 0;
@@ -764,23 +767,27 @@ CopyRenameOneFile(
 	    }
 	}
 	if (result != TCL_OK) {
-	    Tcl_AppendResult(interp, "can't unlink \"", TclGetString(errfile),
-		    "\": ", Tcl_PosixError(interp), NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf("can't unlink \"%s\": %s",
+		    TclGetString(errfile), Tcl_PosixError(interp)));
 	    errfile = NULL;
 	}
     }
 
   done:
     if (errfile != NULL) {
-	Tcl_AppendResult(interp, "error ", (copyFlag ? "copying" : "renaming"),
-		 " \"", TclGetString(source), NULL);
+	Tcl_Obj *errorMsg = Tcl_ObjPrintf("error %s \"%s\"",
+		(copyFlag ? "copying" : "renaming"), TclGetString(source));
+
 	if (errfile != source) {
-	    Tcl_AppendResult(interp, "\" to \"", TclGetString(target), NULL);
+	    Tcl_AppendPrintfToObj(errorMsg, " to \"%s\"",
+		    TclGetString(target));
 	    if (errfile != target) {
-		Tcl_AppendResult(interp, "\": \"", TclGetString(errfile),NULL);
+		Tcl_AppendPrintfToObj(errorMsg, ": \"%s\"",
+			TclGetString(errfile));
 	    }
 	}
-	Tcl_AppendResult(interp, "\": ", Tcl_PosixError(interp), NULL);
+	Tcl_AppendPrintfToObj(errorMsg, ": %s", Tcl_PosixError(interp));
+	Tcl_SetObjResult(interp, errorMsg);
     }
     if (errorBuffer != NULL) {
 	Tcl_DecrRefCount(errorBuffer);
@@ -983,9 +990,10 @@ TclFileAttrsCmd(
 		 * There was an error, probably that the filePtr is not
 		 * accepted by any filesystem
 		 */
-		Tcl_AppendResult(interp, "could not read \"",
-			TclGetString(filePtr), "\": ", Tcl_PosixError(interp),
-			NULL);
+
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"could not read \"%s\": %s",
+			TclGetString(filePtr), Tcl_PosixError(interp)));
 	    }
 	    return TCL_ERROR;
 	}
@@ -1071,9 +1079,9 @@ TclFileAttrsCmd(
 	Tcl_Obj *objPtr = NULL;
 
 	if (numObjStrings == 0) {
-	    Tcl_AppendResult(interp, "bad option \"", TclGetString(objv[0]),
-		    "\", there are no file attributes in this filesystem.",
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "bad option \"%s\", there are no file attributes in this"
+		    " filesystem", TclGetString(objv[0])));
 	    Tcl_SetErrorCode(interp, "TCL","OPERATION","FATTR","NONE", NULL);
 	    goto end;
 	}
@@ -1098,9 +1106,9 @@ TclFileAttrsCmd(
 	int i, index;
 
 	if (numObjStrings == 0) {
-	    Tcl_AppendResult(interp, "bad option \"", TclGetString(objv[0]),
-		    "\", there are no file attributes in this filesystem.",
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "bad option \"%s\", there are no file attributes in this"
+		    " filesystem", TclGetString(objv[0])));
 	    Tcl_SetErrorCode(interp, "TCL","OPERATION","FATTR","NONE", NULL);
 	    goto end;
 	}
@@ -1114,8 +1122,8 @@ TclFileAttrsCmd(
 		TclFreeIntRep(objv[i]);
 	    }
 	    if (i + 1 == objc) {
-		Tcl_AppendResult(interp, "value for \"",
-			TclGetString(objv[i]), "\" missing", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"value for \"%s\" missing", TclGetString(objv[i])));
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "FATTR",
 			"NOVALUE", NULL);
 		goto end;
@@ -1224,9 +1232,9 @@ TclFileLinkCmd(
 	     */
 
 	    if (errno == EEXIST) {
-		Tcl_AppendResult(interp, "could not create new link \"",
-			TclGetString(objv[index]),
-			"\": that path already exists", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"could not create new link \"%s\": that path already"
+			" exists", TclGetString(objv[index])));
 		Tcl_PosixError(interp);
 	    } else if (errno == ENOENT) {
 		/*
@@ -1244,23 +1252,23 @@ TclFileLinkCmd(
 		access = Tcl_FSAccess(dirPtr, F_OK);
 		Tcl_DecrRefCount(dirPtr);
 		if (access != 0) {
-		    Tcl_AppendResult(interp, "could not create new link \"",
-			    TclGetString(objv[index]),
-			    "\": no such file or directory", NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			    "could not create new link \"%s\": no such file"
+			    " or directory", TclGetString(objv[index])));
 		    Tcl_PosixError(interp);
 		} else {
-		    Tcl_AppendResult(interp, "could not create new link \"",
-			    TclGetString(objv[index]), "\": target \"",
-			    TclGetString(objv[index+1]), "\" doesn't exist",
-			    NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			    "could not create new link \"%s\": target \"%s\" "
+			    "doesn't exist", TclGetString(objv[index]),
+			    TclGetString(objv[index+1])));
 		    errno = ENOENT;
 		    Tcl_PosixError(interp);
 		}
 	    } else {
-		Tcl_AppendResult(interp, "could not create new link \"",
-			TclGetString(objv[index]), "\" pointing to \"",
-			TclGetString(objv[index+1]), "\": ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"could not create new link \"%s\" pointing to \"%s\": %s",
+			TclGetString(objv[index]),
+			TclGetString(objv[index+1]), Tcl_PosixError(interp)));
 	    }
 	    return TCL_ERROR;
 	}
@@ -1275,9 +1283,9 @@ TclFileLinkCmd(
 
 	contents = Tcl_FSLink(objv[index], NULL, 0);
 	if (contents == NULL) {
-	    Tcl_AppendResult(interp, "could not read link \"",
-		    TclGetString(objv[index]), "\": ", Tcl_PosixError(interp),
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "could not read link \"%s\": %s",
+		    TclGetString(objv[index]), Tcl_PosixError(interp)));
 	    return TCL_ERROR;
 	}
     }
@@ -1332,8 +1340,9 @@ TclFileReadLinkCmd(
     contents = Tcl_FSLink(objv[1], NULL, 0);
 
     if (contents == NULL) {
-	Tcl_AppendResult(interp, "could not readlink \"",
-		TclGetString(objv[1]), "\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"could not read link \"%s\": %s",
+		TclGetString(objv[1]), Tcl_PosixError(interp)));
 	return TCL_ERROR;
     }
     Tcl_SetObjResult(interp, contents);
@@ -1487,8 +1496,8 @@ TclFileTemporaryCmd(
 	if (nameVarObj) {
 	    TclDecrRefCount(nameObj);
 	}
-	Tcl_AppendResult(interp, "can't create temporary file: ",
-		Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"can't create temporary file: %s", Tcl_PosixError(interp)));
 	return TCL_ERROR;
     }
     Tcl_RegisterChannel(interp, chan);
@@ -1499,7 +1508,7 @@ TclFileTemporaryCmd(
 	    return TCL_ERROR;
 	}
     }
-    Tcl_AppendResult(interp, Tcl_GetChannelName(chan), NULL);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(Tcl_GetChannelName(chan), -1));
     return TCL_OK;
 }
 
diff --git a/generic/tclFileName.c b/generic/tclFileName.c
index edb6581..5d90351 100644
--- a/generic/tclFileName.c
+++ b/generic/tclFileName.c
@@ -1174,9 +1174,10 @@ DoTildeSubst(
 	dir = TclGetEnv("HOME", &dirString);
 	if (dir == NULL) {
 	    if (interp) {
-		Tcl_ResetResult(interp);
-		Tcl_AppendResult(interp, "couldn't find HOME environment "
-			"variable to expand path", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"couldn't find HOME environment "
+			"variable to expand path", -1));
+		Tcl_SetErrorCode(interp, "TCL", "FILENAME", "NO_HOME", NULL);
 	    }
 	    return NULL;
 	}
@@ -1185,8 +1186,9 @@ DoTildeSubst(
     } else if (TclpGetUserHome(user, resultPtr) == NULL) {
 	if (interp) {
 	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "user \"", user, "\" doesn't exist",
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "user \"%s\" doesn't exist", user));
+	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "USER", user, NULL);
 	}
 	return NULL;
     }
@@ -1329,9 +1331,9 @@ Tcl_GlobObjCmd(
 
   endOfForLoop:
     if ((globFlags & TCL_GLOBMODE_TAILS) && (pathOrDir == NULL)) {
-	Tcl_AppendResult(interp,
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		"\"-tails\" must be used with either "
-		"\"-directory\" or \"-path\"", NULL);
+		"\"-directory\" or \"-path\"", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "GLOB",
 		"BADOPTIONCOMBINATION", NULL);
 	return TCL_ERROR;
@@ -1625,20 +1627,23 @@ Tcl_GlobObjCmd(
 	}
 
 	if (length == 0) {
-	    Tcl_AppendResult(interp, "no files matched glob pattern",
-		    (join || (objc == 1)) ? " \"" : "s \"", NULL);
+	    Tcl_Obj *errorMsg =
+		    Tcl_ObjPrintf("no files matched glob pattern%s \"",
+			    (join || (objc == 1)) ? "" : "s");
+
 	    if (join) {
-		Tcl_AppendResult(interp, Tcl_DStringValue(&prefix), NULL);
+		Tcl_AppendToObj(errorMsg, Tcl_DStringValue(&prefix), -1);
 	    } else {
 		const char *sep = "";
 
 		for (i = 0; i < objc; i++) {
-		    string = Tcl_GetString(objv[i]);
-		    Tcl_AppendResult(interp, sep, string, NULL);
+		    Tcl_AppendPrintfToObj(errorMsg, "%s%s",
+			    sep, Tcl_GetString(objv[i]));
 		    sep = " ";
 		}
 	    }
-	    Tcl_AppendResult(interp, "\"", NULL);
+	    Tcl_AppendToObj(errorMsg, "\"", -1);
+	    Tcl_SetObjResult(interp, errorMsg);
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "GLOB", "NOMATCH",
 		    NULL);
 	    result = TCL_ERROR;
@@ -2206,15 +2211,15 @@ DoGlob(
 		closeBrace = p;
 		break;
 	    }
-	    Tcl_SetResult(interp, "unmatched open-brace in file name",
-		    TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "unmatched open-brace in file name", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "GLOB", "BALANCE",
 		    NULL);
 	    return TCL_ERROR;
 
 	} else if (*p == '}') {
-	    Tcl_SetResult(interp, "unmatched close-brace in file name",
-		    TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "unmatched close-brace in file name", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "GLOB", "BALANCE",
 		    NULL);
 	    return TCL_ERROR;
diff --git a/generic/tclIO.c b/generic/tclIO.c
index 2de8b53..4e24533 100644
--- a/generic/tclIO.c
+++ b/generic/tclIO.c
@@ -1027,8 +1027,9 @@ Tcl_UnregisterChannel(
 
     if (GotFlag(statePtr, CHANNEL_INCLOSE)) {
 	if (interp != NULL) {
-	    Tcl_AppendResult(interp, "Illegal recursive call to close "
-		    "through close-handler of channel", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                    "illegal recursive call to close through close-handler"
+                    " of channel", -1));
 	}
 	return TCL_ERROR;
     }
@@ -1263,8 +1264,8 @@ Tcl_GetChannel(
     hTblPtr = GetChannelTable(interp);
     hPtr = Tcl_FindHashEntry(hTblPtr, name);
     if (hPtr == NULL) {
-	Tcl_AppendResult(interp, "can not find channel named \"", chanName,
-		"\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can not find channel named \"%s\"", chanName));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "CHANNEL", chanName, NULL);
 	return NULL;
     }
@@ -1584,8 +1585,9 @@ Tcl_StackChannel(
 
     if (statePtr == NULL) {
 	if (interp) {
-	    Tcl_AppendResult(interp, "couldn't find state for channel \"",
-		    Tcl_GetChannelName(prevChan), "\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "couldn't find state for channel \"%s\"",
+		    Tcl_GetChannelName(prevChan)));
 	}
 	return NULL;
     }
@@ -1605,9 +1607,9 @@ Tcl_StackChannel(
 
     if ((mask & (statePtr->flags & (TCL_READABLE | TCL_WRITABLE))) == 0) {
 	if (interp) {
-	    Tcl_AppendResult(interp,
-		    "reading and writing both disallowed for channel \"",
-		    Tcl_GetChannelName(prevChan), "\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "reading and writing both disallowed for channel \"%s\"",
+		    Tcl_GetChannelName(prevChan)));
 	}
 	return NULL;
     }
@@ -1630,8 +1632,9 @@ Tcl_StackChannel(
 	    statePtr->csPtrR = csPtrR;
 	    statePtr->csPtrW = csPtrW;
 	    if (interp) {
-		Tcl_AppendResult(interp, "could not flush channel \"",
-			Tcl_GetChannelName(prevChan), "\"", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                        "could not flush channel \"%s\"",
+			Tcl_GetChannelName(prevChan)));
 	    }
 	    return NULL;
 	}
@@ -1784,9 +1787,9 @@ Tcl_UnstackChannel(
 		 */
 
 		if (!TclChanCaughtErrorBypass(interp, chan) && interp) {
-		    Tcl_AppendResult(interp, "could not flush channel \"",
-			    Tcl_GetChannelName((Tcl_Channel) chanPtr), "\"",
-			    NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                            "could not flush channel \"%s\"",
+			    Tcl_GetChannelName((Tcl_Channel) chanPtr)));
 		}
 		return TCL_ERROR;
 	    }
@@ -2318,8 +2321,8 @@ CheckForDeadChannel(
 
     Tcl_SetErrno(EINVAL);
     if (interp) {
-	Tcl_AppendResult(interp, "unable to access channel: invalid channel",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "unable to access channel: invalid channel", -1));
     }
     return 1;
 }
@@ -3051,8 +3054,9 @@ Tcl_Close(
 
     if (GotFlag(statePtr, CHANNEL_INCLOSE)) {
 	if (interp) {
-	    Tcl_AppendResult(interp, "Illegal recursive call to close "
-		    "through close-handler of channel", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                    "illegal recursive call to close through close-handler"
+                    " of channel", -1));
 	}
 	return TCL_ERROR;
     }
@@ -3210,8 +3214,9 @@ Tcl_CloseEx(
      */
 
     if (!chanPtr->typePtr->close2Proc) {
-	Tcl_AppendResult(interp, "Half-close of channels not supported by ",
-		chanPtr->typePtr->typeName, "s", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "half-close of channels not supported by %ss",
+		chanPtr->typePtr->typeName));
 	return TCL_ERROR;
     }
 
@@ -3220,9 +3225,8 @@ Tcl_CloseEx(
      */
 
     if (chanPtr != statePtr->topChanPtr) {
-	Tcl_AppendResult(interp,
-		"Half-close not applicable to stack of transformations",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"half-close not applicable to stack of transformations", -1));
 	return TCL_ERROR;
     }
 
@@ -3240,9 +3244,9 @@ Tcl_CloseEx(
 	} else {
 	    msg = "write";
 	}
-	Tcl_AppendResult(interp, "Half-close of ", msg,
-		"-side not possible, side not opened or already closed",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "Half-close of %s-side not possible, side not opened or"
+                " already closed", msg));
 	return TCL_ERROR;
     }
 
@@ -3253,8 +3257,9 @@ Tcl_CloseEx(
 
     if (statePtr->flags & CHANNEL_INCLOSE) {
 	if (interp) {
-	    Tcl_AppendResult(interp, "Illegal recursive call to close "
-		    "through close-handler of channel", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                    "illegal recursive call to close through close-handler"
+                    " of channel", -1));
 	}
 	return TCL_ERROR;
     }
@@ -7547,6 +7552,7 @@ Tcl_BadChannelOption(
 	const char **argv;
 	int argc, i;
 	Tcl_DString ds;
+        Tcl_Obj *errObj;
 
 	Tcl_DStringInit(&ds);
 	Tcl_DStringAppend(&ds, genericopt, -1);
@@ -7559,13 +7565,14 @@ Tcl_BadChannelOption(
 	    Tcl_Panic("malformed option list in channel driver");
 	}
 	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "bad option \"", optionName,
-		"\": should be one of ", NULL);
+	errObj = Tcl_ObjPrintf("bad option \"%s\": should be one of ",
+                optionName);
 	argc--;
 	for (i = 0; i < argc; i++) {
-	    Tcl_AppendResult(interp, "-", argv[i], ", ", NULL);
+	    Tcl_AppendPrintfToObj(errObj, "-%s, ", argv[i]);
 	}
-	Tcl_AppendResult(interp, "or -", argv[i], NULL);
+	Tcl_AppendPrintfToObj(errObj, "or -%s", argv[i]);
+        Tcl_SetObjResult(interp, errObj);
 	Tcl_DStringFree(&ds);
 	ckfree(argv);
     }
@@ -7843,8 +7850,9 @@ Tcl_SetChannelOption(
 
     if (statePtr->csPtrR || statePtr->csPtrW) {
 	if (interp) {
-	    Tcl_AppendResult(interp, "unable to set channel options: "
-		    "background copy in progress", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                    "unable to set channel options: background copy in"
+                    " progress", -1));
 	}
 	return TCL_ERROR;
     }
@@ -7893,8 +7901,9 @@ Tcl_SetChannelOption(
 	    ResetFlag(statePtr, CHANNEL_LINEBUFFERED);
 	    SetFlag(statePtr, CHANNEL_UNBUFFERED);
 	} else if (interp) {
-            Tcl_AppendResult(interp, "bad value for -buffering: "
-		    "must be one of full, line, or none", NULL);
+            Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                    "bad value for -buffering: must be one of"
+                    " full, line, or none", -1));
             return TCL_ERROR;
 	}
 	return TCL_OK;
@@ -7949,8 +7958,9 @@ Tcl_SetChannelOption(
 
 	    if (inValue & 0x80 || outValue & 0x80) {
 		if (interp) {
-		    Tcl_AppendResult(interp, "bad value for -eofchar: ",
-			    "must be non-NUL ASCII character", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                            "bad value for -eofchar: must be non-NUL ASCII"
+                            " character", -1));
 		}
 		ckfree(argv);
 		return TCL_ERROR;
@@ -7963,9 +7973,9 @@ Tcl_SetChannelOption(
 	    }
 	} else {
 	    if (interp) {
-		Tcl_AppendResult(interp,
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			"bad value for -eofchar: should be a list of zero,"
-			" one, or two elements", NULL);
+			" one, or two elements", -1));
 	    }
 	    ckfree(argv);
 	    return TCL_ERROR;
@@ -7997,9 +8007,9 @@ Tcl_SetChannelOption(
 	    writeMode = GotFlag(statePtr, TCL_WRITABLE) ? argv[1] : NULL;
 	} else {
 	    if (interp) {
-		Tcl_AppendResult(interp,
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			"bad value for -translation: must be a one or two"
-			" element list", NULL);
+			" element list", -1));
 	    }
 	    ckfree(argv);
 	    return TCL_ERROR;
@@ -8027,10 +8037,9 @@ Tcl_SetChannelOption(
 		translation = TCL_PLATFORM_TRANSLATION;
 	    } else {
 		if (interp) {
-		    Tcl_AppendResult(interp,
-			    "bad value for -translation: "
-			    "must be one of auto, binary, cr, lf, crlf,"
-			    " or platform", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "bad value for -translation: must be one of "
+                            "auto, binary, cr, lf, crlf, or platform", -1));
 		}
 		ckfree(argv);
 		return TCL_ERROR;
@@ -8078,10 +8087,9 @@ Tcl_SetChannelOption(
 		statePtr->outputTranslation = TCL_PLATFORM_TRANSLATION;
 	    } else {
 		if (interp) {
-		    Tcl_AppendResult(interp,
-			    "bad value for -translation: "
-			    "must be one of auto, binary, cr, lf, crlf,"
-			    " or platform", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "bad value for -translation: must be one of "
+                            "auto, binary, cr, lf, crlf, or platform", -1));
 		}
 		ckfree(argv);
 		return TCL_ERROR;
@@ -8901,8 +8909,8 @@ Tcl_FileEventObjCmd(
     chanPtr = (Channel *) chan;
     statePtr = chanPtr->state;
     if ((statePtr->flags & mask) == 0) {
-	Tcl_AppendResult(interp, "channel is not ",
-		(mask == TCL_READABLE) ? "readable" : "writable", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf("channel is not %s",
+		(mask == TCL_READABLE) ? "readable" : "writable"));
 	return TCL_ERROR;
     }
 
@@ -9023,15 +9031,15 @@ TclCopyChannel(
 
     if (BUSY_STATE(inStatePtr, TCL_READABLE)) {
 	if (interp) {
-	    Tcl_AppendResult(interp, "channel \"",
-		    Tcl_GetChannelName(inChan), "\" is busy", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "channel \"%s\" is busy", Tcl_GetChannelName(inChan)));
 	}
 	return TCL_ERROR;
     }
     if (BUSY_STATE(outStatePtr, TCL_WRITABLE)) {
 	if (interp) {
-	    Tcl_AppendResult(interp, "channel \"",
-		    Tcl_GetChannelName(outChan), "\" is busy", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "channel \"%s\" is busy", Tcl_GetChannelName(outChan)));
 	}
 	return TCL_ERROR;
     }
@@ -10157,8 +10165,9 @@ SetBlockMode(
 	     */
 
 	    if (!TclChanCaughtErrorBypass(interp, (Tcl_Channel) chanPtr)) {
-		Tcl_AppendResult(interp, "error setting blocking mode: ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                        "error setting blocking mode: %s",
+			Tcl_PosixError(interp)));
 	    }
 	} else {
 	    /*
diff --git a/generic/tclIOCmd.c b/generic/tclIOCmd.c
index 59856d0..005713d 100644
--- a/generic/tclIOCmd.c
+++ b/generic/tclIOCmd.c
@@ -174,9 +174,10 @@ Tcl_PutsObjCmd(
     if (TclGetChannelFromObj(interp, chanObjPtr, &chan, &mode, 0) != TCL_OK) {
 	return TCL_ERROR;
     }
-    if ((mode & TCL_WRITABLE) == 0) {
-	Tcl_AppendResult(interp, "channel \"", TclGetString(chanObjPtr),
-		"\" wasn't opened for writing", NULL);
+    if (!(mode & TCL_WRITABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for writing",
+		TclGetString(chanObjPtr)));
 	return TCL_ERROR;
     }
 
@@ -201,8 +202,8 @@ Tcl_PutsObjCmd(
 
   error:
     if (!TclChanCaughtErrorBypass(interp, chan)) {
-	Tcl_AppendResult(interp, "error writing \"", TclGetString(chanObjPtr),
-		"\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf("error writing \"%s\": %s",
+		TclGetString(chanObjPtr), Tcl_PosixError(interp)));
     }
     return TCL_ERROR;
 }
@@ -244,9 +245,10 @@ Tcl_FlushObjCmd(
     if (TclGetChannelFromObj(interp, chanObjPtr, &chan, &mode, 0) != TCL_OK) {
 	return TCL_ERROR;
     }
-    if ((mode & TCL_WRITABLE) == 0) {
-	Tcl_AppendResult(interp, "channel \"", TclGetString(chanObjPtr),
-		"\" wasn't opened for writing", NULL);
+    if (!(mode & TCL_WRITABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for writing",
+		TclGetString(chanObjPtr)));
 	return TCL_ERROR;
     }
 
@@ -259,9 +261,9 @@ Tcl_FlushObjCmd(
 	 */
 
 	if (!TclChanCaughtErrorBypass(interp, chan)) {
-	    Tcl_AppendResult(interp, "error flushing \"",
-		    TclGetString(chanObjPtr), "\": ", Tcl_PosixError(interp),
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "error flushing \"%s\": %s",
+		    TclGetString(chanObjPtr), Tcl_PosixError(interp)));
 	}
 	return TCL_ERROR;
     }
@@ -306,9 +308,10 @@ Tcl_GetsObjCmd(
     if (TclGetChannelFromObj(interp, chanObjPtr, &chan, &mode, 0) != TCL_OK) {
 	return TCL_ERROR;
     }
-    if ((mode & TCL_READABLE) == 0) {
-	Tcl_AppendResult(interp, "channel \"", TclGetString(chanObjPtr),
-		"\" wasn't opened for reading", NULL);
+    if (!(mode & TCL_READABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for reading",
+		TclGetString(chanObjPtr)));
 	return TCL_ERROR;
     }
 
@@ -326,10 +329,9 @@ Tcl_GetsObjCmd(
 	     */
 
 	    if (!TclChanCaughtErrorBypass(interp, chan)) {
-		Tcl_ResetResult(interp);
-		Tcl_AppendResult(interp, "error reading \"",
-			TclGetString(chanObjPtr), "\": ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"error reading \"%s\": %s",
+			TclGetString(chanObjPtr), Tcl_PosixError(interp)));
 	    }
 	    return TCL_ERROR;
 	}
@@ -411,9 +413,10 @@ Tcl_ReadObjCmd(
     if (TclGetChannelFromObj(interp, chanObjPtr, &chan, &mode, 0) != TCL_OK) {
 	return TCL_ERROR;
     }
-    if ((mode & TCL_READABLE) == 0) {
-	Tcl_AppendResult(interp, "channel \"", TclGetString(chanObjPtr),
-		"\" wasn't opened for reading", NULL);
+    if (!(mode & TCL_READABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for reading",
+		TclGetString(chanObjPtr)));
 	return TCL_ERROR;
     }
     i++;			/* Consumed channel name. */
@@ -436,11 +439,11 @@ Tcl_ReadObjCmd(
 
 	    if (strcmp(TclGetString(objv[i]), "nonewline") != 0) {
 #endif
-	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "expected non-negative integer but got \"",
-		    TclGetString(objv[i]), "\"", NULL);
-	    Tcl_SetErrorCode(interp, "TCL", "VALUE", "NUMBER", NULL);
-	    return TCL_ERROR;
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"expected non-negative integer but got \"%s\"",
+			TclGetString(objv[i])));
+		Tcl_SetErrorCode(interp, "TCL", "VALUE", "NUMBER", NULL);
+		return TCL_ERROR;
 #if TCL_MAJOR_VERSION < 9
 	    }
 	    newline = 1;
@@ -460,10 +463,9 @@ Tcl_ReadObjCmd(
 	 */
 
 	if (!TclChanCaughtErrorBypass(interp, chan)) {
-	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "error reading \"",
-		    TclGetString(chanObjPtr), "\": ", Tcl_PosixError(interp),
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "error reading \"%s\": %s",
+		    TclGetString(chanObjPtr), Tcl_PosixError(interp)));
 	}
 	Tcl_DecrRefCount(resultPtr);
 	return TCL_ERROR;
@@ -552,9 +554,9 @@ Tcl_SeekObjCmd(
 	 */
 
 	if (!TclChanCaughtErrorBypass(interp, chan)) {
-	    Tcl_AppendResult(interp, "error during seek on \"",
-		    TclGetString(objv[1]), "\": ", Tcl_PosixError(interp),
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "error during seek on \"%s\": %s",
+		    TclGetString(objv[1]), Tcl_PosixError(interp)));
 	}
 	return TCL_ERROR;
     }
@@ -679,9 +681,9 @@ Tcl_CloseObjCmd(
 	 */
 
 	if (!(dir & Tcl_GetChannelMode(chan))) {
-	    Tcl_AppendResult(interp, "Half-close of ", dirOptions[index],
-		    "-side not possible, side not opened or already closed",
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "Half-close of %s-side not possible, side not opened"
+		    " or already closed", dirOptions[index]));
 	    return TCL_ERROR;
 	}
 
@@ -977,9 +979,9 @@ Tcl_ExecObjCmd(
 	     */
 
 	    if (!TclChanCaughtErrorBypass(interp, chan)) {
-		Tcl_ResetResult(interp);
-		Tcl_AppendResult(interp, "error reading output from command: ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"error reading output from command: %s",
+			Tcl_PosixError(interp)));
 		Tcl_DecrRefCount(resultPtr);
 	    }
 	    return TCL_ERROR;
@@ -1048,9 +1050,10 @@ Tcl_FblockedObjCmd(
     if (TclGetChannelFromObj(interp, objv[1], &chan, &mode, 0) != TCL_OK) {
 	return TCL_ERROR;
     }
-    if ((mode & TCL_READABLE) == 0) {
-	Tcl_AppendResult(interp, "channel \"", TclGetString(objv[1]),
-		"\" wasn't opened for reading", NULL);
+    if (!(mode & TCL_READABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for reading",
+		TclGetString(objv[1])));
 	return TCL_ERROR;
     }
 
@@ -1174,7 +1177,7 @@ Tcl_OpenObjCmd(
 	return TCL_ERROR;
     }
     Tcl_RegisterChannel(interp, chan);
-    Tcl_AppendResult(interp, Tcl_GetChannelName(chan), NULL);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(Tcl_GetChannelName(chan), -1));
     return TCL_OK;
 }
 
@@ -1479,8 +1482,8 @@ Tcl_SocketObjCmd(
 	switch ((enum socketOptions) optionIndex) {
 	case SKT_ASYNC:
 	    if (server == 1) {
-		Tcl_AppendResult(interp,
-			"cannot set -async option for server sockets", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"cannot set -async option for server sockets", -1));
 		return TCL_ERROR;
 	    }
 	    async = 1;
@@ -1488,8 +1491,8 @@ Tcl_SocketObjCmd(
 	case SKT_MYADDR:
 	    a++;
 	    if (a >= objc) {
-		Tcl_AppendResult(interp,
-			"no argument given for -myaddr option", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"no argument given for -myaddr option", -1));
 		return TCL_ERROR;
 	    }
 	    myaddr = TclGetString(objv[a]);
@@ -1499,8 +1502,8 @@ Tcl_SocketObjCmd(
 
 	    a++;
 	    if (a >= objc) {
-		Tcl_AppendResult(interp,
-			"no argument given for -myport option", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"no argument given for -myport option", -1));
 		return TCL_ERROR;
 	    }
 	    myPortName = TclGetString(objv[a]);
@@ -1511,15 +1514,15 @@ Tcl_SocketObjCmd(
 	}
 	case SKT_SERVER:
 	    if (async == 1) {
-		Tcl_AppendResult(interp,
-			"cannot set -async option for server sockets", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"cannot set -async option for server sockets", -1));
 		return TCL_ERROR;
 	    }
 	    server = 1;
 	    a++;
 	    if (a >= objc) {
-		Tcl_AppendResult(interp,
-			"no argument given for -server option", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"no argument given for -server option", -1));
 		return TCL_ERROR;
 	    }
 	    script = TclGetString(objv[a]);
@@ -1531,8 +1534,8 @@ Tcl_SocketObjCmd(
     if (server) {
 	host = myaddr;		/* NULL implies INADDR_ANY */
 	if (myport != 0) {
-	    Tcl_AppendResult(interp, "option -myport is not valid for servers",
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "option -myport is not valid for servers", -1));
 	    return TCL_ERROR;
 	}
     } else if (a < objc) {
@@ -1599,9 +1602,9 @@ Tcl_SocketObjCmd(
 	    return TCL_ERROR;
 	}
     }
-    Tcl_RegisterChannel(interp, chan);
-    Tcl_AppendResult(interp, Tcl_GetChannelName(chan), NULL);
 
+    Tcl_RegisterChannel(interp, chan);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(Tcl_GetChannelName(chan), -1));
     return TCL_OK;
 }
 
@@ -1651,17 +1654,19 @@ Tcl_FcopyObjCmd(
     if (TclGetChannelFromObj(interp, objv[1], &inChan, &mode, 0) != TCL_OK) {
 	return TCL_ERROR;
     }
-    if ((mode & TCL_READABLE) == 0) {
-	Tcl_AppendResult(interp, "channel \"", TclGetString(objv[1]),
-		"\" wasn't opened for reading", NULL);
+    if (!(mode & TCL_READABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for reading",
+		TclGetString(objv[1])));
 	return TCL_ERROR;
     }
     if (TclGetChannelFromObj(interp, objv[2], &outChan, &mode, 0) != TCL_OK) {
 	return TCL_ERROR;
     }
-    if ((mode & TCL_WRITABLE) == 0) {
-	Tcl_AppendResult(interp, "channel \"", TclGetString(objv[2]),
-		"\" wasn't opened for writing", NULL);
+    if (!(mode & TCL_WRITABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for writing",
+		TclGetString(objv[2])));
 	return TCL_ERROR;
     }
 
@@ -1745,14 +1750,14 @@ ChanPendingObjCmd(
 
     switch ((enum options) index) {
     case PENDING_INPUT:
-	if ((mode & TCL_READABLE) == 0) {
+	if (!(mode & TCL_READABLE)) {
 	    Tcl_SetObjResult(interp, Tcl_NewIntObj(-1));
 	} else {
 	    Tcl_SetObjResult(interp, Tcl_NewIntObj(Tcl_InputBuffered(chan)));
 	}
 	break;
     case PENDING_OUTPUT:
-	if ((mode & TCL_WRITABLE) == 0) {
+	if (!(mode & TCL_WRITABLE)) {
 	    Tcl_SetObjResult(interp, Tcl_NewIntObj(-1));
 	} else {
 	    Tcl_SetObjResult(interp, Tcl_NewIntObj(Tcl_OutputBuffered(chan)));
@@ -1806,8 +1811,8 @@ ChanTruncateObjCmd(
 	    return TCL_ERROR;
 	}
 	if (length < 0) {
-	    Tcl_AppendResult(interp,
-		    "cannot truncate to negative length of file", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "cannot truncate to negative length of file", -1));
 	    return TCL_ERROR;
 	}
     } else {
@@ -1817,18 +1822,17 @@ ChanTruncateObjCmd(
 
 	length = Tcl_Tell(chan);
 	if (length == Tcl_WideAsLong(-1)) {
-	    Tcl_AppendResult(interp,
-		    "could not determine current location in \"",
-		    TclGetString(objv[1]), "\": ",
-		    Tcl_PosixError(interp), NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "could not determine current location in \"%s\": %s",
+		    TclGetString(objv[1]), Tcl_PosixError(interp)));
 	    return TCL_ERROR;
 	}
     }
 
     if (Tcl_TruncateChannel(chan, length) != TCL_OK) {
-	Tcl_AppendResult(interp, "error during truncate on \"",
-		TclGetString(objv[1]), "\": ",
-		Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"error during truncate on \"%s\": %s",
+		TclGetString(objv[1]), Tcl_PosixError(interp)));
 	return TCL_ERROR;
     }
 
diff --git a/generic/tclIOGT.c b/generic/tclIOGT.c
index 6f80c25..bfe6a10 100644
--- a/generic/tclIOGT.c
+++ b/generic/tclIOGT.c
@@ -284,8 +284,8 @@ TclChannelTransform(
     dataPtr->self = Tcl_StackChannel(interp, &transformChannelType, dataPtr,
 	    mode, chan);
     if (dataPtr->self == NULL) {
-	Tcl_AppendResult(interp, "\nfailed to stack channel \"",
-		Tcl_GetChannelName(chan), "\"", NULL);
+	Tcl_AppendPrintfToObj(Tcl_GetObjResult(interp),
+		"\nfailed to stack channel \"%s\"", Tcl_GetChannelName(chan));
 	Tcl_DecrRefCount(dataPtr->command);
 	ResultClear(&dataPtr->result);
 	ckfree(dataPtr);
diff --git a/generic/tclIORChan.c b/generic/tclIORChan.c
index 6fec40a..a354d60 100644
--- a/generic/tclIORChan.c
+++ b/generic/tclIORChan.c
@@ -404,25 +404,25 @@ static int		ForwardProc(Tcl_Event *evPtr, int mask);
 static void		SrcExitProc(ClientData clientData);
 
 #define FreeReceivedError(p) \
-	if ((p)->base.mustFree) { \
-	    ckfree((p)->base.msgStr); \
+	if ((p)->base.mustFree) {                               \
+	    ckfree((p)->base.msgStr);                           \
 	}
 #define PassReceivedErrorInterp(i,p) \
-	if ((i) != NULL) { \
-	    Tcl_SetChannelErrorInterp((i), \
-		    Tcl_NewStringObj((p)->base.msgStr, -1)); \
-	} \
+	if ((i) != NULL) {                                      \
+	    Tcl_SetChannelErrorInterp((i),                      \
+		    Tcl_NewStringObj((p)->base.msgStr, -1));    \
+	}                                                       \
 	FreeReceivedError(p)
 #define PassReceivedError(c,p) \
 	Tcl_SetChannelError((c), Tcl_NewStringObj((p)->base.msgStr, -1)); \
 	FreeReceivedError(p)
 #define ForwardSetStaticError(p,emsg) \
-	(p)->base.code = TCL_ERROR; \
-	(p)->base.mustFree = 0; \
+	(p)->base.code = TCL_ERROR;                             \
+	(p)->base.mustFree = 0;                                 \
 	(p)->base.msgStr = (char *) (emsg)
 #define ForwardSetDynamicError(p,emsg) \
-	(p)->base.code = TCL_ERROR; \
-	(p)->base.mustFree = 1; \
+	(p)->base.code = TCL_ERROR;                             \
+	(p)->base.mustFree = 1;                                 \
 	(p)->base.msgStr = (char *) (emsg)
 
 static void		ForwardSetObjError(ForwardParam *p, Tcl_Obj *objPtr);
@@ -739,7 +739,8 @@ TclChanCreateObjCmd(
      * Return handle as result of command.
      */
 
-    Tcl_SetResult(interp, (char *)chanPtr->state->channelName, TCL_VOLATILE);
+    Tcl_SetObjResult(interp,
+            Tcl_NewStringObj(chanPtr->state->channelName, -1));
     return TCL_OK;
 
   error:
@@ -774,13 +775,15 @@ TclChanCreateObjCmd(
  */
 
 typedef struct ReflectEvent {
-    Tcl_Event         header;
-    ReflectedChannel* rcPtr;
-    int               events;
+    Tcl_Event header;
+    ReflectedChannel *rcPtr;
+    int events;
 } ReflectEvent;
 
 static int
-ReflectEventRun (Tcl_Event* ev, int flags)
+ReflectEventRun(
+    Tcl_Event *ev,
+    int flags)
 {
     /* OWNER thread
      *
@@ -789,14 +792,16 @@ ReflectEventRun (Tcl_Event* ev, int flags)
      * accomplishing that.
      */
 
-    ReflectEvent* e = (ReflectEvent*) ev;
+    ReflectEvent *e = (ReflectEvent *) ev;
 
-    Tcl_NotifyChannel (e->rcPtr->chan, e->events);
+    Tcl_NotifyChannel(e->rcPtr->chan, e->events);
     return 1;
 }
 
 static int
-ReflectEventDelete (Tcl_Event* ev, ClientData cd)
+ReflectEventDelete(
+    Tcl_Event *ev,
+    ClientData cd)
 {
     /* OWNER thread
      *
@@ -805,11 +810,9 @@ ReflectEventDelete (Tcl_Event* ev, ClientData cd)
      * invalid channel.
      */
 
-    ReflectEvent* e = (ReflectEvent*) ev;
+    ReflectEvent *e = (ReflectEvent *) ev;
 
-    if ((ev->proc != ReflectEventRun) ||
-        ((cd != NULL) &&
-         (cd != e->rcPtr))) {
+    if ((ev->proc != ReflectEventRun) || ((cd != NULL) && (cd != e->rcPtr))) {
         return 0;
     }
     return 1;
@@ -867,8 +870,8 @@ TclChanPostEventObjCmd(
     hPtr = Tcl_FindHashEntry(&rcmPtr->map, chanId);
 
     if (hPtr == NULL) {
-	Tcl_AppendResult(interp, "can not find reflected channel named \"",
-		chanId, "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can not find reflected channel named \"%s\"", chanId));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "CHANNEL", chanId, NULL);
 	return TCL_ERROR;
     }
@@ -925,8 +928,9 @@ TclChanPostEventObjCmd(
      */
 
     if (events & ~rcPtr->interest) {
-	Tcl_AppendResult(interp, "tried to post events channel \"", chanId,
-		"\" is not interested in", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "tried to post events channel \"%s\" is not interested in",
+                chanId));
 	return TCL_ERROR;
     }
 
@@ -937,10 +941,11 @@ TclChanPostEventObjCmd(
 #ifdef TCL_THREADS
     if (rcPtr->owner == rcPtr->thread) {
 #endif
-        Tcl_NotifyChannel (chan, events);
+        Tcl_NotifyChannel(chan, events);
 #ifdef TCL_THREADS
     } else {
-        ReflectEvent* ev = ckalloc (sizeof (ReflectEvent));
+        ReflectEvent *ev = ckalloc(sizeof(ReflectEvent));
+
         ev->header.proc = ReflectEventRun;
         ev->events = events;
         ev->rcPtr = rcPtr;
@@ -957,7 +962,8 @@ TclChanPostEventObjCmd(
          * The teardown of unprocessed events is currently coupled to the
          * thread reflected channel map
          */
-        (void) GetThreadReflectedChannelMap ();
+
+        (void) GetThreadReflectedChannelMap();
 
         /* XXX Race condition !!
          * XXX The destination thread may not exist anymore already.
@@ -965,8 +971,9 @@ TclChanPostEventObjCmd(
          * XXX Can we detect this ? (check the validity of the owner threadid ?)
          * XXX Actually, in that case the channel should be dead also !
          */
-        Tcl_ThreadQueueEvent (rcPtr->owner, (Tcl_Event*) ev, TCL_QUEUE_TAIL);
-        Tcl_ThreadAlert (rcPtr->owner);
+
+        Tcl_ThreadQueueEvent(rcPtr->owner, (Tcl_Event *) ev, TCL_QUEUE_TAIL);
+        Tcl_ThreadAlert(rcPtr->owner);
     }
 #endif
 
@@ -1156,8 +1163,11 @@ ReflectClose(
 	    ForwardOpToHandlerThread(rcPtr, ForwardedClose, &p);
 	    result = p.base.code;
 
-            /* Now squash the pending reflection events for this channel. */
-            Tcl_DeleteEvents (ReflectEventDelete, rcPtr);
+            /*
+             * Now squash the pending reflection events for this channel.
+             */
+
+            Tcl_DeleteEvents(ReflectEventDelete, rcPtr);
 
 	    if (result != TCL_OK) {
 		FreeReceivedError(&p);
@@ -1165,7 +1175,7 @@ ReflectClose(
 	}
 #endif
 
-        Tcl_EventuallyFree (rcPtr, (Tcl_FreeProc *) FreeReflectedChannel);
+        Tcl_EventuallyFree(rcPtr, (Tcl_FreeProc *) FreeReflectedChannel);
 	return EOK;
     }
 
@@ -1177,7 +1187,7 @@ ReflectClose(
      */
 
     if (rcPtr->methods == 0) {
-        Tcl_EventuallyFree (rcPtr, (Tcl_FreeProc *) FreeReflectedChannel);
+        Tcl_EventuallyFree(rcPtr, (Tcl_FreeProc *) FreeReflectedChannel);
 	return EOK;
     }
 
@@ -1192,10 +1202,13 @@ ReflectClose(
 	ForwardOpToHandlerThread(rcPtr, ForwardedClose, &p);
 	result = p.base.code;
 
-        /* Now squash the pending reflection events for this channel. */
-        Tcl_DeleteEvents (ReflectEventDelete, rcPtr);
+        /*
+         * Now squash the pending reflection events for this channel.
+         */
 
-        Tcl_EventuallyFree (rcPtr, (Tcl_FreeProc *) FreeReflectedChannel);
+        Tcl_DeleteEvents(ReflectEventDelete, rcPtr);
+
+        Tcl_EventuallyFree(rcPtr, (Tcl_FreeProc *) FreeReflectedChannel);
 
 	if (result != TCL_OK) {
 	    PassReceivedErrorInterp(interp, &p);
@@ -1240,7 +1253,7 @@ ReflectClose(
 	}
 #endif
 
-        Tcl_EventuallyFree (rcPtr, (Tcl_FreeProc *) FreeReflectedChannel);
+        Tcl_EventuallyFree(rcPtr, (Tcl_FreeProc *) FreeReflectedChannel);
 #ifdef TCL_THREADS
     }
 #endif
@@ -1348,7 +1361,7 @@ ReflectInput(
     *errorCodePtr = EOK;
 
     if (bytec > 0) {
-	memcpy(buf, bytev, (size_t)bytec);
+	memcpy(buf, bytev, (size_t) bytec);
     }
 
  stop:
@@ -1549,12 +1562,13 @@ ReflectSeekWide(
     Tcl_Preserve(rcPtr);
 
     offObj  = Tcl_NewWideIntObj(offset);
-    baseObj = Tcl_NewStringObj((seekMode == SEEK_SET) ? "start" :
-                               ((seekMode == SEEK_CUR) ? "current" : "end"), -1);
+    baseObj = Tcl_NewStringObj(
+            (seekMode == SEEK_SET) ? "start" :
+            (seekMode == SEEK_CUR) ? "current" : "end", -1);
     Tcl_IncrRefCount(offObj);
     Tcl_IncrRefCount(baseObj);
 
-    if (InvokeTclMethod(rcPtr, "seek", offObj, baseObj, &resObj)!=TCL_OK) {
+    if (InvokeTclMethod(rcPtr, "seek", offObj, baseObj, &resObj) != TCL_OK) {
 	Tcl_SetChannelError(rcPtr->chan, resObj);
         goto invalid;
     }
@@ -1772,7 +1786,7 @@ ReflectThread(ClientData clientData, int action)
         rcPtr->owner = NULL;
         break;
     default:
-        Tcl_Panic ("Unknown thread action code.");
+        Tcl_Panic("Unknown thread action code.");
         break;
     }
 }
@@ -2046,7 +2060,8 @@ EncodeEventMask(
     }
 
     if (listc < 1) {
-	Tcl_AppendResult(interp, "bad ", objName, " list: is empty", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "bad %s list: is empty", objName));
 	return TCL_ERROR;
     }
 
@@ -2807,7 +2822,7 @@ DeleteThreadReflectedChannelMap(
      * actually.
      */
 
-    Tcl_DeleteEvents (ReflectEventDelete, NULL);
+    Tcl_DeleteEvents(ReflectEventDelete, NULL);
 
     /*
      * Get the map of all channels handled by the current thread. This is a
@@ -2978,9 +2993,8 @@ ForwardProc(
     Tcl_Interp *interp = rcPtr->interp;
     ForwardParam *paramPtr = evPtr->param;
     Tcl_Obj *resObj = NULL;	/* Interp result of InvokeTclMethod */
-    ReflectedChannelMap *rcmPtr;
-    /* Map of reflected channels with handlers in
-     * this interp. */
+    ReflectedChannelMap *rcmPtr;/* Map of reflected channels with handlers in
+                                 * this interp. */
     Tcl_HashEntry *hPtr;	/* Entry in the above map */
 
     /*
@@ -3023,12 +3037,12 @@ ForwardProc(
 
 	rcmPtr = GetReflectedChannelMap(interp);
 	hPtr = Tcl_FindHashEntry(&rcmPtr->map,
-                                 Tcl_GetChannelName(rcPtr->chan));
+                Tcl_GetChannelName(rcPtr->chan));
 	Tcl_DeleteHashEntry(hPtr);
 
 	rcmPtr = GetThreadReflectedChannelMap();
 	hPtr = Tcl_FindHashEntry(&rcmPtr->map,
-                                 Tcl_GetChannelName(rcPtr->chan));
+                Tcl_GetChannelName(rcPtr->chan));
 	Tcl_DeleteHashEntry(hPtr);
 
 	FreeReflectedChannelArgs(rcPtr);
@@ -3063,7 +3077,7 @@ ForwardProc(
 		paramPtr->input.toRead = -1;
 	    } else {
 		if (bytec > 0) {
-		    memcpy(paramPtr->input.buf, bytev, (size_t)bytec);
+		    memcpy(paramPtr->input.buf, bytev, (size_t) bytec);
 		}
 		paramPtr->input.toRead = bytec;
 	    }
@@ -3075,7 +3089,7 @@ ForwardProc(
 
     case ForwardedOutput: {
 	Tcl_Obj *bufObj = Tcl_NewByteArrayObj((unsigned char *)
-                                              paramPtr->output.buf, paramPtr->output.toWrite);
+                paramPtr->output.buf, paramPtr->output.toWrite);
         Tcl_IncrRefCount(bufObj);
 
         Tcl_Preserve(rcPtr);
@@ -3115,8 +3129,8 @@ ForwardProc(
     case ForwardedSeek: {
 	Tcl_Obj *offObj = Tcl_NewWideIntObj(paramPtr->seek.offset);
 	Tcl_Obj *baseObj = Tcl_NewStringObj(
-                                            (paramPtr->seek.seekMode==SEEK_SET) ? "start" :
-                                            (paramPtr->seek.seekMode==SEEK_CUR) ? "current" : "end", -1);
+                (paramPtr->seek.seekMode==SEEK_SET) ? "start" :
+                (paramPtr->seek.seekMode==SEEK_CUR) ? "current" : "end", -1);
 
         Tcl_IncrRefCount(offObj);
         Tcl_IncrRefCount(baseObj);
@@ -3166,11 +3180,11 @@ ForwardProc(
 
     case ForwardedBlock: {
 	Tcl_Obj *blockObj = Tcl_NewBooleanObj(!paramPtr->block.nonblocking);
-        Tcl_IncrRefCount(blockObj);
 
+        Tcl_IncrRefCount(blockObj);
         Tcl_Preserve(rcPtr);
 	if (InvokeTclMethod(rcPtr, "blocking", blockObj, NULL,
-                            &resObj) != TCL_OK) {
+                &resObj) != TCL_OK) {
 	    ForwardSetObjError(paramPtr, resObj);
 	}
         Tcl_Release(rcPtr);
@@ -3186,7 +3200,7 @@ ForwardProc(
         Tcl_IncrRefCount(valueObj);
         Tcl_Preserve(rcPtr);
 	if (InvokeTclMethod(rcPtr, "configure", optionObj, valueObj,
-                            &resObj) != TCL_OK) {
+                &resObj) != TCL_OK) {
 	    ForwardSetObjError(paramPtr, resObj);
 	}
         Tcl_Release(rcPtr);
@@ -3201,8 +3215,8 @@ ForwardProc(
 	 */
 
 	Tcl_Obj *optionObj = Tcl_NewStringObj(paramPtr->getOpt.name, -1);
-        Tcl_IncrRefCount(optionObj);
 
+        Tcl_IncrRefCount(optionObj);
         Tcl_Preserve(rcPtr);
 	if (InvokeTclMethod(rcPtr, "cget", optionObj, NULL, &resObj)!=TCL_OK){
 	    ForwardSetObjError(paramPtr, resObj);
diff --git a/generic/tclIORTrans.c b/generic/tclIORTrans.c
index 8f111b0..2b9efb9 100644
--- a/generic/tclIORTrans.c
+++ b/generic/tclIORTrans.c
@@ -363,33 +363,43 @@ static int		ForwardProc(Tcl_Event *evPtr, int mask);
 static void		SrcExitProc(ClientData clientData);
 
 #define FreeReceivedError(p) \
-	if ((p)->base.mustFree) { \
-	    ckfree((p)->base.msgStr); \
-	}
+	do {								\
+	    if ((p)->base.mustFree) {					\
+		ckfree((p)->base.msgStr);				\
+	    }								\
+	} while (0)
 #define PassReceivedErrorInterp(i,p) \
-	if ((i) != NULL) { \
-	    Tcl_SetChannelErrorInterp((i), \
-		    Tcl_NewStringObj((p)->base.msgStr, -1)); \
-	} \
-	FreeReceivedError(p)
+	do {								\
+	    if ((i) != NULL) {						\
+		Tcl_SetChannelErrorInterp((i),				\
+			Tcl_NewStringObj((p)->base.msgStr, -1));	\
+	    }								\
+	    FreeReceivedError(p);					\
+	} while (0)
 #define PassReceivedError(c,p) \
-	Tcl_SetChannelError((c), Tcl_NewStringObj((p)->base.msgStr, -1)); \
-	FreeReceivedError(p)
+	do {								\
+	    Tcl_SetChannelError((c),					\
+		    Tcl_NewStringObj((p)->base.msgStr, -1));		\
+	    FreeReceivedError(p);					\
+	} while (0)
 #define ForwardSetStaticError(p,emsg) \
-	(p)->base.code = TCL_ERROR; \
-	(p)->base.mustFree = 0; \
-	(p)->base.msgStr = (char *) (emsg)
+	do {								\
+	    (p)->base.code = TCL_ERROR;					\
+	    (p)->base.mustFree = 0;					\
+	    (p)->base.msgStr = (char *) (emsg);				\
+	} while (0)
 #define ForwardSetDynamicError(p,emsg) \
-	(p)->base.code = TCL_ERROR; \
-	(p)->base.mustFree = 1; \
-	(p)->base.msgStr = (char *) (emsg)
+	do {								\
+	    (p)->base.code = TCL_ERROR;					\
+	    (p)->base.mustFree = 1;					\
+	    (p)->base.msgStr = (char *) (emsg);				\
+	} while (0)
 
 static void		ForwardSetObjError(ForwardParam *p,
 			    Tcl_Obj *objPtr);
-
 static ReflectedTransformMap *	GetThreadReflectedTransformMap(void);
-static void		DeleteThreadReflectedTransformMap(ClientData clientData);
-
+static void		DeleteThreadReflectedTransformMap(
+			    ClientData clientData);
 #endif /* TCL_THREADS */
 
 #define SetChannelErrorStr(c,msgStr) \
@@ -513,7 +523,6 @@ TclChanPushObjCmd(
     int result;			/* Result code for 'initialize' */
     Tcl_Obj *resObj;		/* Result data for 'initialize' */
     int methods;		/* Bitmask for supported methods. */
-    Tcl_Obj *err;		/* Error message */
     ReflectedTransformMap *rtmPtr;
 				/* Map of reflected transforms with handlers
 				 * in this interp. */
@@ -608,11 +617,10 @@ TclChanPushObjCmd(
     while (listc > 0) {
 	if (Tcl_GetIndexFromObj(interp, listv[listc-1], methodNames,
 		"method", TCL_EXACT, &methIndex) != TCL_OK) {
-	    TclNewLiteralStringObj(err, "chan handler \"");
-	    Tcl_AppendObjToObj(err, cmdObj);
-	    Tcl_AppendToObj(err, " initialize\" returned ", -1);
-	    Tcl_AppendObjToObj(err, Tcl_GetObjResult(interp));
-	    Tcl_SetObjResult(interp, err);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "chan handler \"%s initialize\" returned %s",
+		    Tcl_GetString(cmdObj),
+		    Tcl_GetString(Tcl_GetObjResult(interp))));
 	    Tcl_DecrRefCount(resObj);
 	    goto error;
 	}
@@ -695,13 +703,14 @@ TclChanPushObjCmd(
     rtmPtr = GetThreadReflectedTransformMap();
     hPtr = Tcl_CreateHashEntry(&rtmPtr->map, Tcl_GetString(rtId), &isNew);
     Tcl_SetHashValue(hPtr, rtPtr);
-#endif
+#endif /* TCL_THREADS */
 
     /*
      * Return the channel as the result of the command.
      */
 
-    Tcl_AppendResult(interp, Tcl_GetChannelName(rtPtr->chan), NULL);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+	    Tcl_GetChannelName(rtPtr->chan), -1));
     return TCL_OK;
 
   error:
@@ -710,7 +719,7 @@ TclChanPushObjCmd(
      * structure.
      */
 
-    Tcl_EventuallyFree (rtPtr, (Tcl_FreeProc *) FreeReflectedTransform);
+    Tcl_EventuallyFree(rtPtr, (Tcl_FreeProc *) FreeReflectedTransform);
     return TCL_ERROR;
 
 #undef CHAN
@@ -913,9 +922,9 @@ ReflectClose(
 		FreeReceivedError(&p);
 	    }
 	}
-#endif
+#endif /* TCL_THREADS */
 
-	Tcl_EventuallyFree (rtPtr, (Tcl_FreeProc *) FreeReflectedTransform);
+	Tcl_EventuallyFree(rtPtr, (Tcl_FreeProc *) FreeReflectedTransform);
 	return EOK;
     }
 
@@ -931,11 +940,11 @@ ReflectClose(
 	if (!TransformDrain(rtPtr, &errorCode)) {
 #ifdef TCL_THREADS
 	    if (rtPtr->thread != Tcl_GetCurrentThread()) {
-		Tcl_EventuallyFree (rtPtr,
+		Tcl_EventuallyFree(rtPtr,
 			(Tcl_FreeProc *) FreeReflectedTransform);
 		return errorCode;
 	    } 
-#endif
+#endif /* TCL_THREADS */
 	    errorCodeSet = 1;
 	    goto cleanup;
 	}
@@ -945,11 +954,11 @@ ReflectClose(
 	if (!TransformFlush(rtPtr, &errorCode, FLUSH_WRITE)) {
 #ifdef TCL_THREADS
 	    if (rtPtr->thread != Tcl_GetCurrentThread()) {
-		Tcl_EventuallyFree (rtPtr,
+		Tcl_EventuallyFree(rtPtr,
 			(Tcl_FreeProc *) FreeReflectedTransform);
 		return errorCode;
 	    } 
-#endif
+#endif /* TCL_THREADS */
 	    errorCodeSet = 1;
 	    goto cleanup;
 	}
@@ -966,7 +975,7 @@ ReflectClose(
 	ForwardOpToOwnerThread(rtPtr, ForwardedClose, &p);
 	result = p.base.code;
 
-	Tcl_EventuallyFree (rtPtr, (Tcl_FreeProc *) FreeReflectedTransform);
+	Tcl_EventuallyFree(rtPtr, (Tcl_FreeProc *) FreeReflectedTransform);
 
 	if (result != TCL_OK) {
 	    PassReceivedErrorInterp(interp, &p);
@@ -974,7 +983,7 @@ ReflectClose(
 	}
 	return EOK;
     }
-#endif
+#endif /* TCL_THREADS */
 
     /*
      * Do the actual invokation of "finalize" now; we're in the right thread.
@@ -1022,7 +1031,7 @@ ReflectClose(
 	if (hPtr) {
 	    Tcl_DeleteHashEntry(hPtr);
 	}
-#endif
+#endif /* TCL_THREADS */
     }
 
     Tcl_EventuallyFree (rtPtr, (Tcl_FreeProc *) FreeReflectedTransform);
@@ -1348,7 +1357,7 @@ ReflectSeekWide(
 	 * transformation.
 	 */
 
-	if ((rtPtr->methods & FLAG(METH_CLEAR))) {
+	if (rtPtr->methods & FLAG(METH_CLEAR)) {
 	    TransformClear(rtPtr);
 	}
 
@@ -2140,7 +2149,7 @@ DeleteReflectedTransformMap(
     ForwardingResult *resultPtr;
     ForwardingEvent *evPtr;
     ForwardParam *paramPtr;
-#endif
+#endif /* TCL_THREADS */
 
     /*
      * Delete all entries. The channels may have been closed already, or will
@@ -2232,8 +2241,7 @@ DeleteReflectedTransformMap(
 	Tcl_ConditionNotify(&resultPtr->done);
     }
     Tcl_MutexUnlock(&rtForwardMutex);
-
-#endif
+#endif /* TCL_THREADS */
 }
 
 #ifdef TCL_THREADS
@@ -2631,7 +2639,7 @@ ForwardProc(
 	break;
     }
 
-    case ForwardedDrain: {
+    case ForwardedDrain:
 	if (InvokeTclMethod(rtPtr, "drain", NULL, NULL, &resObj) != TCL_OK) {
 	    ForwardSetObjError(paramPtr, resObj);
 	    paramPtr->transform.size = -1;
@@ -2656,9 +2664,8 @@ ForwardProc(
 	    }
 	}
 	break;
-    }
 
-    case ForwardedFlush: {
+    case ForwardedFlush:
 	if (InvokeTclMethod(rtPtr, "flush", NULL, NULL, &resObj) != TCL_OK) {
 	    ForwardSetObjError(paramPtr, resObj);
 	    paramPtr->transform.size = -1;
@@ -2684,12 +2691,10 @@ ForwardProc(
 	    }
 	}
 	break;
-    }
 
-    case ForwardedClear: {
+    case ForwardedClear:
 	(void) InvokeTclMethod(rtPtr, "clear", NULL, NULL, NULL);
 	break;
-    }
 
     case ForwardedLimit:
 	if (InvokeTclMethod(rtPtr, "limit?", NULL, NULL, &resObj) != TCL_OK) {
@@ -2795,7 +2800,7 @@ ForwardSetObjError(
     ForwardSetDynamicError(paramPtr, ckalloc(len));
     memcpy(paramPtr->base.msgStr, msgStr, (unsigned) len);
 }
-#endif
+#endif /* TCL_THREADS */
 
 /*
  *----------------------------------------------------------------------
@@ -3092,7 +3097,7 @@ TransformRead(
 	ckfree(p.transform.buf);
 	return 1;
     }
-#endif
+#endif /* TCL_THREADS */
 
     /* ASSERT: rtPtr->method & FLAG(METH_READ) */
     /* ASSERT: rtPtr->mode & TCL_READABLE */
@@ -3153,7 +3158,7 @@ TransformWrite(
 		p.transform.size);
 	ckfree(p.transform.buf);
     } else
-#endif
+#endif /* TCL_THREADS */
     {
 	/* ASSERT: rtPtr->method & FLAG(METH_WRITE) */
 	/* ASSERT: rtPtr->mode & TCL_WRITABLE */
@@ -3215,7 +3220,7 @@ TransformDrain(
 	ResultAdd(&rtPtr->result, UCHARP(p.transform.buf), p.transform.size);
 	ckfree(p.transform.buf);
     } else
-#endif
+#endif /* TCL_THREADS */
     {
 	if (InvokeTclMethod(rtPtr, "drain", NULL, NULL, &resObj)!=TCL_OK) {
 	    Tcl_SetChannelError(rtPtr->chan, resObj);
@@ -3270,7 +3275,7 @@ TransformFlush(
 	}
 	ckfree(p.transform.buf);
     } else
-#endif
+#endif /* TCL_THREADS */
     {
 	if (InvokeTclMethod(rtPtr, "flush", NULL, NULL, &resObj)!=TCL_OK) {
 	    Tcl_SetChannelError(rtPtr->chan, resObj);
@@ -3311,7 +3316,7 @@ TransformClear(
 	ForwardOpToOwnerThread(rtPtr, ForwardedClear, &p);
 	return;
     }
-#endif
+#endif /* TCL_THREADS */
 
     /* ASSERT: rtPtr->method & FLAG(METH_READ) */
     /* ASSERT: rtPtr->mode & TCL_READABLE */
diff --git a/generic/tclIOSock.c b/generic/tclIOSock.c
index 018f9f5..e603c91 100644
--- a/generic/tclIOSock.c
+++ b/generic/tclIOSock.c
@@ -64,8 +64,8 @@ TclSockGetPort(
 	return TCL_ERROR;
     }
     if (*portPtr > 0xFFFF) {
-	Tcl_AppendResult(interp, "couldn't open socket: port number too high",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"couldn't open socket: port number too high", -1));
 	return TCL_ERROR;
     }
     return TCL_OK;
@@ -100,16 +100,20 @@ TclSockMinimumBuffers(
     socklen_t len;
 
     len = sizeof(int);
-    getsockopt((SOCKET)(size_t)sock, SOL_SOCKET, SO_SNDBUF, (char *)&current, &len);
+    getsockopt((SOCKET)(size_t) sock, SOL_SOCKET, SO_SNDBUF,
+	    (char *) &current, &len);
     if (current < size) {
 	len = sizeof(int);
-	setsockopt((SOCKET)(size_t)sock, SOL_SOCKET, SO_SNDBUF, (char *)&size, len);
+	setsockopt((SOCKET)(size_t) sock, SOL_SOCKET, SO_SNDBUF,
+		(char *) &size, len);
     }
     len = sizeof(int);
-    getsockopt((SOCKET)(size_t)sock, SOL_SOCKET, SO_RCVBUF, (char *)&current, &len);
+    getsockopt((SOCKET)(size_t) sock, SOL_SOCKET, SO_RCVBUF,
+		(char *) &current, &len);
     if (current < size) {
 	len = sizeof(int);
-	setsockopt((SOCKET)(size_t)sock, SOL_SOCKET, SO_RCVBUF, (char *)&size, len);
+	setsockopt((SOCKET)(size_t) sock, SOL_SOCKET, SO_RCVBUF,
+		(char *) &size, len);
     }
     return TCL_OK;
 }
@@ -152,19 +156,18 @@ TclCreateSocketAddress(
     Tcl_DString ds;
     int result, i;
 
-    TclFormatInt(portstring, port);
-
     if (host != NULL) {
 	native = Tcl_UtfToExternalDString(NULL, host, -1, &ds);
     }
-    
+    TclFormatInt(portstring, port);
     (void) memset(&hints, 0, sizeof(hints));
-    
     hints.ai_family = AF_UNSPEC;
+
     /* 
      * Magic variable to enforce a certain address family - to be superseded
      * by a TIP that adds explicit switches to [socket]
      */
+
     if (interp != NULL) {
         family = Tcl_GetVar(interp, "::tcl::unsupported::socketAF", 0);
         if (family != NULL) {
@@ -182,7 +185,7 @@ TclCreateSocketAddress(
     /*
      * We found some problems when using AI_ADDRCONFIG, e.g. on systems that
      * have no networking besides the loopback interface and want to resolve
-     * localhost. See bugs 3385024, 3382419, 3382431. As the advantage of
+     * localhost. See [Bugs 3385024, 3382419, 3382431]. As the advantage of
      * using AI_ADDRCONFIG in situations where it works, is probably low,
      * we'll leave it out for now. After all, it is just an optimisation.
      *
@@ -206,12 +209,11 @@ TclCreateSocketAddress(
     }
 
     if (result != 0) {
-#ifdef EAI_SYSTEM /* Doesn't exist on Windows */
-        if (result == EAI_SYSTEM)
-            *errorMsgPtr = Tcl_PosixError(interp);
-        else
-#endif
-            *errorMsgPtr = gai_strerror(result);
+	*errorMsgPtr =
+#ifdef EAI_SYSTEM	/* Doesn't exist on Windows */
+		(result == EAI_SYSTEM) ? Tcl_PosixError(interp) :
+#endif /* EAI_SYSTEM */
+		gai_strerror(result);
         return 0;
     }
 
diff --git a/generic/tclIOUtil.c b/generic/tclIOUtil.c
index 41a5aac..115c132 100644
--- a/generic/tclIOUtil.c
+++ b/generic/tclIOUtil.c
@@ -1094,8 +1094,9 @@ Tcl_FSMatchInDirectory(
     cwd = Tcl_FSGetCwd(NULL);
     if (cwd == NULL) {
 	if (interp != NULL) {
-	    Tcl_SetResult(interp, "glob couldn't determine "
-		    "the current working directory", TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "glob couldn't determine the current working directory",
+		    -1));
 	}
 	return TCL_ERROR;
     }
@@ -1572,8 +1573,8 @@ TclGetOpenModeEx(
 	*seekFlagPtr = 0;
 	*binaryPtr = 0;
 	if (interp != NULL) {
-	    Tcl_AppendResult(interp, "illegal access mode \"", modeString,
-		    "\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "illegal access mode \"%s\"", modeString));
 	}
 	return -1;
     }
@@ -1622,8 +1623,9 @@ TclGetOpenModeEx(
 	    mode |= O_NOCTTY;
 #else
 	    if (interp != NULL) {
-		Tcl_AppendResult(interp, "access mode \"", flag,
-			"\" not supported by this system", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"access mode \"%s\" not supported by this system",
+			flag));
 	    }
 	    ckfree(modeArgv);
 	    return -1;
@@ -1634,8 +1636,9 @@ TclGetOpenModeEx(
 	    mode |= O_NONBLOCK;
 #else
 	    if (interp != NULL) {
-		Tcl_AppendResult(interp, "access mode \"", flag,
-			"\" not supported by this system", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"access mode \"%s\" not supported by this system",
+			flag));
 	    }
 	    ckfree(modeArgv);
 	    return -1;
@@ -1648,9 +1651,10 @@ TclGetOpenModeEx(
 	} else {
 
 	    if (interp != NULL) {
-		Tcl_AppendResult(interp, "invalid access mode \"", flag,
-			"\": must be RDONLY, WRONLY, RDWR, APPEND, BINARY, "
-			"CREAT, EXCL, NOCTTY, NONBLOCK, or TRUNC", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"invalid access mode \"%s\": must be RDONLY, WRONLY, "
+			"RDWR, APPEND, BINARY, CREAT, EXCL, NOCTTY, NONBLOCK,"
+			" or TRUNC", flag));
 	    }
 	    ckfree(modeArgv);
 	    return -1;
@@ -1661,8 +1665,9 @@ TclGetOpenModeEx(
 
     if (!gotRW) {
 	if (interp != NULL) {
-	    Tcl_AppendResult(interp, "access mode must include either"
-		    " RDONLY, WRONLY, or RDWR", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "access mode must include either RDONLY, WRONLY, or RDWR",
+		    -1));
 	}
 	return -1;
     }
@@ -1721,15 +1726,16 @@ Tcl_FSEvalFileEx(
 
     if (Tcl_FSStat(pathPtr, &statBuf) == -1) {
 	Tcl_SetErrno(errno);
-	Tcl_AppendResult(interp, "couldn't read file \"",
-		Tcl_GetString(pathPtr), "\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"couldn't read file \"%s\": %s",
+		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
 	return result;
     }
     chan = Tcl_FSOpenFileChannel(interp, pathPtr, "r", 0644);
     if (chan == NULL) {
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "couldn't read file \"",
-		Tcl_GetString(pathPtr), "\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"couldn't read file \"%s\": %s",
+		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
 	return result;
     }
 
@@ -1763,8 +1769,9 @@ Tcl_FSEvalFileEx(
 
     if (Tcl_ReadChars(chan, objPtr, 1, 0) < 0) {
 	Tcl_Close(interp, chan);
-	Tcl_AppendResult(interp, "couldn't read file \"",
-		Tcl_GetString(pathPtr), "\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"couldn't read file \"%s\": %s",
+		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
 	goto end;
     }
     string = Tcl_GetString(objPtr);
@@ -1777,8 +1784,9 @@ Tcl_FSEvalFileEx(
     if (Tcl_ReadChars(chan, objPtr, -1,
 	    memcmp(string, "\xef\xbb\xbf", 3)) < 0) {
 	Tcl_Close(interp, chan);
-	Tcl_AppendResult(interp, "couldn't read file \"",
-		Tcl_GetString(pathPtr), "\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"couldn't read file \"%s\": %s",
+		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
 	goto end;
     }
 
@@ -1852,15 +1860,16 @@ TclNREvalFile(
 
     if (Tcl_FSStat(pathPtr, &statBuf) == -1) {
 	Tcl_SetErrno(errno);
-	Tcl_AppendResult(interp, "couldn't read file \"",
-		Tcl_GetString(pathPtr), "\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"couldn't read file \"%s\": %s",
+		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
 	return TCL_ERROR;
     }
     chan = Tcl_FSOpenFileChannel(interp, pathPtr, "r", 0644);
     if (chan == NULL) {
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "couldn't read file \"",
-		Tcl_GetString(pathPtr), "\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"couldn't read file \"%s\": %s",
+		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
 	return TCL_ERROR;
     }
 
@@ -1894,8 +1903,9 @@ TclNREvalFile(
 
     if (Tcl_ReadChars(chan, objPtr, 1, 0) < 0) {
 	Tcl_Close(interp, chan);
-	Tcl_AppendResult(interp, "couldn't read file \"",
-		Tcl_GetString(pathPtr), "\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"couldn't read file \"%s\": %s",
+		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
 	Tcl_DecrRefCount(objPtr);
 	return TCL_ERROR;
     }
@@ -1909,8 +1919,9 @@ TclNREvalFile(
     if (Tcl_ReadChars(chan, objPtr, -1,
 	    memcmp(string, "\xef\xbb\xbf", 3)) < 0) {
 	Tcl_Close(interp, chan);
-	Tcl_AppendResult(interp, "couldn't read file \"",
-		Tcl_GetString(pathPtr), "\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"couldn't read file \"%s\": %s",
+		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
 	Tcl_DecrRefCount(objPtr);
 	return TCL_ERROR;
     }
@@ -2246,9 +2257,9 @@ Tcl_FSOpenFileChannel(
 	if (seekFlag && Tcl_Seek(retVal, (Tcl_WideInt) 0, SEEK_END)
 		< (Tcl_WideInt) 0) {
 	    if (interp != NULL) {
-		Tcl_AppendResult(interp, "could not seek to end of file "
-			"while opening \"", Tcl_GetString(pathPtr), "\": ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"could not seek to end of file while opening \"%s\": %s",
+			Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
 	    }
 	    Tcl_Close(NULL, retVal);
 	    return NULL;
@@ -2265,8 +2276,9 @@ Tcl_FSOpenFileChannel(
 
     Tcl_SetErrno(ENOENT);
     if (interp != NULL) {
-	Tcl_AppendResult(interp, "couldn't open \"", Tcl_GetString(pathPtr),
-		"\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"couldn't open \"%s\": %s",
+		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
     }
     return NULL;
 }
@@ -2684,9 +2696,9 @@ Tcl_FSGetCwd(
 		Disclaim();
 		goto cdDidNotChange;
 	    } else if (interp != NULL) {
-		Tcl_AppendResult(interp,
-			"error getting working directory name: ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"error getting working directory name: %s",
+			Tcl_PosixError(interp)));
 	    }
 	}
 	Disclaim();
@@ -2760,9 +2772,9 @@ Tcl_FSGetCwd(
 
 	    retCd = proc2(tsdPtr->cwdClientData);
 	    if (retCd == NULL && interp != NULL) {
-		Tcl_AppendResult(interp,
-			"error getting working directory name: ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"error getting working directory name: %s",
+			Tcl_PosixError(interp)));
 	    }
 
 	    if (retCd == tsdPtr->cwdClientData) {
@@ -3152,8 +3164,9 @@ Tcl_LoadFile(
      */
 
     if (Tcl_FSAccess(pathPtr, R_OK) != 0) {
-	Tcl_AppendResult(interp, "couldn't load library \"",
-		Tcl_GetString(pathPtr), "\": ", Tcl_PosixError(interp), NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"couldn't load library \"%s\": %s",
+		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
 	return TCL_ERROR;
     }
 
@@ -3203,7 +3216,7 @@ Tcl_LoadFile(
 
   mustCopyToTempAnyway:
     Tcl_ResetResult(interp);
-#endif
+#endif /* TCL_LOAD_FROM_MEMORY */
 
     /*
      * Get a temporary filename to use, first to copy the file into, and then
@@ -3223,8 +3236,8 @@ Tcl_LoadFile(
 
 	Tcl_FSDeleteFile(copyToPtr);
 	Tcl_DecrRefCount(copyToPtr);
-	Tcl_AppendResult(interp, "couldn't load from current filesystem",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"couldn't load from current filesystem", -1));
 	return TCL_ERROR;
     }
 
diff --git a/generic/tclIndexObj.c b/generic/tclIndexObj.c
index 85e0730..731d759 100644
--- a/generic/tclIndexObj.c
+++ b/generic/tclIndexObj.c
@@ -600,8 +600,9 @@ PrefixMatchObjCmd(
 	    flags |= TCL_EXACT;
 	    break;
 	case PRFMATCH_MESSAGE:
-	    if (i > (objc - 4)) {
-		Tcl_AppendResult(interp, "missing message", NULL);
+	    if (i > objc-4) {
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"missing value for -message", -1));
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "NOARG", NULL);
 		return TCL_ERROR;
 	    }
@@ -610,7 +611,8 @@ PrefixMatchObjCmd(
 	    break;
 	case PRFMATCH_ERROR:
 	    if (i > objc-4) {
-		Tcl_AppendResult(interp, "missing error options", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"missing value for -error", -1));
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "NOARG", NULL);
 		return TCL_ERROR;
 	    }
@@ -620,8 +622,9 @@ PrefixMatchObjCmd(
 		return TCL_ERROR;
 	    }
 	    if ((errorLength % 2) != 0) {
-		Tcl_AppendResult(interp, "error options must have an even"
-			" number of elements", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"error options must have an even number of elements",
+			-1));
 		Tcl_SetErrorCode(interp, "TCL", "VALUE", "DICTIONARY", NULL);
 		return TCL_ERROR;
 	    }
@@ -1174,8 +1177,8 @@ Tcl_ParseArgsObjv(
 		goto gotMatch;
 	    }
 	    if (matchPtr != NULL) {
-		Tcl_AppendResult(interp, "ambiguous option \"", str, "\"",
-			NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"ambiguous option \"%s\"", str));
 		goto error;
 	    }
 	    matchPtr = infoPtr;
@@ -1187,8 +1190,8 @@ Tcl_ParseArgsObjv(
 	     */
 
 	    if (remObjv == NULL) {
-		Tcl_AppendResult(interp, "unrecognized argument \"", str,
-			"\"", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"unrecognized argument \"%s\"", str));
 		goto error;
 	    }
 
@@ -1213,9 +1216,9 @@ Tcl_ParseArgsObjv(
 	    }
 	    if (Tcl_GetIntFromObj(interp, objv[srcIndex],
 		    (int *) infoPtr->dstPtr) == TCL_ERROR) {
-		Tcl_AppendResult(interp, "expected integer argument for \"",
-			infoPtr->keyStr, "\" but got \"",
-			Tcl_GetString(objv[srcIndex]), "\"", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"expected integer argument for \"%s\" but got \"%s\"",
+			infoPtr->keyStr, Tcl_GetString(objv[srcIndex])));
 		goto error;
 	    }
 	    srcIndex++;
@@ -1246,9 +1249,9 @@ Tcl_ParseArgsObjv(
 	    }
 	    if (Tcl_GetDoubleFromObj(interp, objv[srcIndex],
 		    (double *) infoPtr->dstPtr) == TCL_ERROR) {
-		Tcl_AppendResult(interp, "expected floating-point argument ",
-			"for \"", infoPtr->keyStr, "\" but got \"",
-			Tcl_GetString(objv[srcIndex]), "\"", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"expected floating-point argument for \"%s\" but got \"%s\"",
+			infoPtr->keyStr, Tcl_GetString(objv[srcIndex])));
 		goto error;
 	    }
 	    srcIndex++;
@@ -1322,8 +1325,8 @@ Tcl_ParseArgsObjv(
      */
 
   missingArg:
-    Tcl_AppendResult(interp, "\"", str,
-	    "\" option requires an additional argument", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "\"%s\" option requires an additional argument", str));
   error:
     if (leftovers != NULL) {
 	ckfree(leftovers);
@@ -1361,6 +1364,7 @@ PrintUsage(
 #define NUM_SPACES 20
     static const char spaces[] = "                    ";
     char tmp[TCL_DOUBLE_SPACE];
+    Tcl_Obj *msg;
 
     /*
      * First, compute the width of the widest option key, so that we can make
@@ -1384,39 +1388,39 @@ PrintUsage(
      * Now add the option information, with pretty-printing.
      */
 
-    Tcl_AppendResult(interp, "Command-specific options:", NULL);
+    msg = Tcl_NewStringObj("Command-specific options:", -1);
     for (infoPtr = argTable; infoPtr->type != TCL_ARGV_END; infoPtr++) {
 	if ((infoPtr->type == TCL_ARGV_HELP) && (infoPtr->keyStr == NULL)) {
-	    Tcl_AppendResult(interp, "\n", infoPtr->helpStr, NULL);
+	    Tcl_AppendPrintfToObj(msg, "\n%s", infoPtr->helpStr);
 	    continue;
 	}
-	Tcl_AppendResult(interp, "\n ", infoPtr->keyStr, ":", NULL);
+	Tcl_AppendPrintfToObj(msg, "\n %s:", infoPtr->keyStr);
 	numSpaces = width + 1 - strlen(infoPtr->keyStr);
 	while (numSpaces > 0) {
 	    if (numSpaces >= NUM_SPACES) {
-		Tcl_AppendResult(interp, spaces, NULL);
+		Tcl_AppendToObj(msg, spaces, NUM_SPACES);
 	    } else {
-		Tcl_AppendResult(interp, spaces+NUM_SPACES-numSpaces, NULL);
+		Tcl_AppendToObj(msg, spaces, numSpaces);
 	    }
 	    numSpaces -= NUM_SPACES;
 	}
-	Tcl_AppendResult(interp, infoPtr->helpStr, NULL);
+	Tcl_AppendToObj(msg, infoPtr->helpStr, -1);
 	switch (infoPtr->type) {
 	case TCL_ARGV_INT:
-	    sprintf(tmp, "%d", *((int *) infoPtr->dstPtr));
-	    Tcl_AppendResult(interp, "\n\t\tDefault value: ", tmp, NULL);
+	    Tcl_AppendPrintfToObj(msg, "\n\t\tDefault value: %d",
+		    *((int *) infoPtr->dstPtr));
 	    break;
 	case TCL_ARGV_FLOAT:
+	    Tcl_AppendPrintfToObj(msg, "\n\t\tDefault value: %g",
+		    *((double *) infoPtr->dstPtr));
 	    sprintf(tmp, "%g", *((double *) infoPtr->dstPtr));
-	    Tcl_AppendResult(interp, "\n\t\tDefault value: ", tmp, NULL);
 	    break;
 	case TCL_ARGV_STRING: {
-	    char *string;
+	    char *string = *((char **) infoPtr->dstPtr);
 
-	    string = *((char **) infoPtr->dstPtr);
 	    if (string != NULL) {
-		Tcl_AppendResult(interp, "\n\t\tDefault value: \"", string,
-			"\"", NULL);
+		Tcl_AppendPrintfToObj(msg, "\n\t\tDefault value: \"%s\"",
+			string);
 	    }
 	    break;
 	}
@@ -1424,6 +1428,7 @@ PrintUsage(
 	    break;
 	}
     }
+    Tcl_SetObjResult(interp, msg);
 }
 
 /*
@@ -1435,8 +1440,8 @@ PrintUsage(
  *
  * Results:
  *	Returns TCL_ERROR if the value is an invalid completion code.
- *	Otherwise, returns TCL_OK, and writes the completion code to
- *  the pointer provided.
+ *	Otherwise, returns TCL_OK, and writes the completion code to the
+ *	pointer provided.
  *
  * Side effects:
  *	None.
@@ -1448,30 +1453,30 @@ int
 TclGetCompletionCodeFromObj(
     Tcl_Interp *interp,		/* Current interpreter. */
     Tcl_Obj *value,
-    int *code)			/* Argument objects. */
+    int *codePtr)		/* Argument objects. */
 {
     static const char *const returnCodes[] = {
 	"ok", "error", "return", "break", "continue", NULL
     };
 
     if ((value->typePtr != &indexType)
-	    && (TCL_OK == TclGetIntFromObj(NULL, value, code))) {
+	    && TclGetIntFromObj(NULL, value, codePtr) == TCL_OK) {
 	return TCL_OK;
     }
-    if (TCL_OK == Tcl_GetIndexFromObj(NULL, value, returnCodes, NULL,
-		TCL_EXACT, code)) {
+    if (Tcl_GetIndexFromObj(NULL, value, returnCodes, NULL, TCL_EXACT,
+	    codePtr) == TCL_OK) {
 	return TCL_OK;
     }
+
     /*
      * Value is not a legal completion code.
      */
 
     if (interp != NULL) {
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "bad completion code \"",
-		TclGetString(value),
-		"\": must be ok, error, return, break, "
-		"continue, or an integer", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"bad completion code \"%s\": must be"
+		" ok, error, return, break, continue, or an integer",
+		TclGetString(value)));
 	Tcl_SetErrorCode(interp, "TCL", "RESULT", "ILLEGAL_CODE", NULL);
     }
     return TCL_ERROR;
diff --git a/generic/tclInterp.c b/generic/tclInterp.c
index 5bae041..0b0f652 100644
--- a/generic/tclInterp.c
+++ b/generic/tclInterp.c
@@ -1043,18 +1043,18 @@ Tcl_InterpObjCmd(
 	iiPtr = (InterpInfo *) ((Interp *) slaveInterp)->interpInfo;
 	hPtr = Tcl_FindHashEntry(&iiPtr->slave.aliasTable, aliasName);
 	if (hPtr == NULL) {
-	    Tcl_AppendResult(interp, "alias \"", aliasName, "\" in path \"",
-		    Tcl_GetString(objv[2]), "\" not found", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "alias \"%s\" in path \"%s\" not found",
+		    aliasName, Tcl_GetString(objv[2])));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ALIAS", aliasName,
 		    NULL);
 	    return TCL_ERROR;
 	}
 	aliasPtr = Tcl_GetHashValue(hPtr);
 	if (Tcl_GetInterpPath(interp, aliasPtr->targetInterp) != TCL_OK) {
-	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "target interpreter for alias \"",
-		    aliasName, "\" in path \"", Tcl_GetString(objv[2]),
-		    "\" is not my descendant", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "target interpreter for alias \"%s\" in path \"%s\" is "
+		    "not my descendant", aliasName, Tcl_GetString(objv[2])));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP",
 		    "TARGETSHROUDED", NULL);
 	    return TCL_ERROR;
@@ -1234,7 +1234,8 @@ Tcl_GetAlias(
 
     hPtr = Tcl_FindHashEntry(&iiPtr->slave.aliasTable, aliasName);
     if (hPtr == NULL) {
-	Tcl_AppendResult(interp, "alias \"", aliasName, "\" not found", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"alias \"%s\" not found", aliasName));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ALIAS", aliasName, NULL);
 	return TCL_ERROR;
     }
@@ -1295,7 +1296,8 @@ Tcl_GetAliasObj(
 
     hPtr = Tcl_FindHashEntry(&iiPtr->slave.aliasTable, aliasName);
     if (hPtr == NULL) {
-	Tcl_AppendResult(interp, "alias \"", aliasName, "\" not found", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"alias \"%s\" not found", aliasName));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ALIAS", aliasName, NULL);
 	return TCL_ERROR;
     }
@@ -1383,9 +1385,9 @@ TclPreventAliasLoop(
 	     * [Bug #641195]
 	     */
 
-	    Tcl_AppendResult(interp, "cannot define or rename alias \"",
-		    Tcl_GetCommandName(cmdInterp, cmd),
-		    "\": interpreter deleted", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "cannot define or rename alias \"%s\": interpreter deleted",
+		    Tcl_GetCommandName(cmdInterp, cmd)));
 	    return TCL_ERROR;
 	}
 	cmdNamePtr = nextAliasPtr->objPtr;
@@ -1398,9 +1400,9 @@ TclPreventAliasLoop(
 	}
 	aliasCmdPtr = (Command *) aliasCmd;
 	if (aliasCmdPtr == cmdPtr) {
-	    Tcl_AppendResult(interp, "cannot define or rename alias \"",
-		    Tcl_GetCommandName(cmdInterp, cmd),
-		    "\": would create a loop", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "cannot define or rename alias \"%s\": would create a loop",
+		    Tcl_GetCommandName(cmdInterp, cmd)));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP",
 		    "ALIASLOOP", NULL);
 	    return TCL_ERROR;
@@ -1621,8 +1623,8 @@ AliasDelete(
     slavePtr = &((InterpInfo *) ((Interp *) slaveInterp)->interpInfo)->slave;
     hPtr = Tcl_FindHashEntry(&slavePtr->aliasTable, TclGetString(namePtr));
     if (hPtr == NULL) {
-	Tcl_AppendResult(interp, "alias \"", TclGetString(namePtr),
-		"\" not found", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"alias \"%s\" not found", TclGetString(namePtr)));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ALIAS",
 		TclGetString(namePtr), NULL);
 	return TCL_ERROR;
@@ -2220,8 +2222,8 @@ GetInterp(
 	}
     }
     if (searchInterp == NULL) {
-	Tcl_AppendResult(interp, "could not find interpreter \"",
-		TclGetString(pathPtr), "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"could not find interpreter \"%s\"", TclGetString(pathPtr)));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "INTERP",
 		TclGetString(pathPtr), NULL);
     }
@@ -2258,8 +2260,8 @@ SlaveBgerror(
 
 	if (TCL_ERROR == TclListObjLength(NULL, objv[0], &length)
 		|| (length < 1)) {
-	    Tcl_AppendResult(interp, "cmdPrefix must be list of length >= 1",
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "cmdPrefix must be list of length >= 1", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP",
 		    "BGERRORFORMAT", NULL);
 	    return TCL_ERROR;
@@ -2328,8 +2330,9 @@ SlaveCreate(
     hPtr = Tcl_CreateHashEntry(&masterInfoPtr->master.slaveTable, path,
 	    &isNew);
     if (isNew == 0) {
-	Tcl_AppendResult(interp, "interpreter named \"", path,
-		"\" already exists, cannot create", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"interpreter named \"%s\" already exists, cannot create",
+		path));
 	return NULL;
     }
 
@@ -2862,8 +2865,8 @@ SlaveRecursionLimit(
 
     if (objc) {
 	if (Tcl_IsSafe(interp)) {
-	    Tcl_AppendResult(interp, "permission denied: "
-		    "safe interpreters cannot change recursion limit", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj("permission denied: "
+		    "safe interpreters cannot change recursion limit", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP", "UNSAFE",
 		    NULL);
 	    return TCL_ERROR;
@@ -3322,8 +3325,8 @@ Tcl_LimitCheck(
 	if (iPtr->limit.cmdCount >= iPtr->cmdCount) {
 	    iPtr->limit.exceeded &= ~TCL_LIMIT_COMMANDS;
 	} else if (iPtr->limit.exceeded & TCL_LIMIT_COMMANDS) {
-	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "command count limit exceeded", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "command count limit exceeded", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "LIMIT", "COMMANDS", NULL);
 	    Tcl_Release(interp);
 	    return TCL_ERROR;
@@ -3348,8 +3351,8 @@ Tcl_LimitCheck(
 		    iPtr->limit.time.usec >= now.usec)) {
 		iPtr->limit.exceeded &= ~TCL_LIMIT_TIME;
 	    } else if (iPtr->limit.exceeded & TCL_LIMIT_TIME) {
-		Tcl_ResetResult(interp);
-		Tcl_AppendResult(interp, "time limit exceeded", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"time limit exceeded", -1));
 		Tcl_SetErrorCode(interp, "TCL", "LIMIT", "TIME", NULL);
 		Tcl_Release(interp);
 		return TCL_ERROR;
@@ -4355,8 +4358,9 @@ SlaveCommandLimitCmd(
      */
 
     if (interp == slaveInterp) {
-	Tcl_AppendResult(interp,
-		"limits on current interpreter inaccessible", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"limits on current interpreter inaccessible", -1));
+	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP", "SELF", NULL);
 	return TCL_ERROR;
     }
 
@@ -4452,8 +4456,8 @@ SlaveCommandLimitCmd(
 		    return TCL_ERROR;
 		}
 		if (gran < 1) {
-		    Tcl_AppendResult(interp, "granularity must be at "
-			    "least 1", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "granularity must be at least 1", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP",
 			    "BADVALUE", NULL);
 		    return TCL_ERROR;
@@ -4469,8 +4473,8 @@ SlaveCommandLimitCmd(
 		    return TCL_ERROR;
 		}
 		if (limit < 0) {
-		    Tcl_AppendResult(interp, "command limit value must be at "
-			    "least 0", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "command limit value must be at least 0", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP",
 			    "BADVALUE", NULL);
 		    return TCL_ERROR;
@@ -4542,8 +4546,9 @@ SlaveTimeLimitCmd(
      */
 
     if (interp == slaveInterp) {
-	Tcl_AppendResult(interp,
-		"limits on current interpreter inaccessible", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"limits on current interpreter inaccessible", -1));
+	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP", "SELF", NULL);
 	return TCL_ERROR;
     }
 
@@ -4660,8 +4665,8 @@ SlaveTimeLimitCmd(
 		    return TCL_ERROR;
 		}
 		if (gran < 1) {
-		    Tcl_AppendResult(interp, "granularity must be at "
-			    "least 1", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "granularity must be at least 1", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP",
 			    "BADVALUE", NULL);
 		    return TCL_ERROR;
@@ -4677,13 +4682,13 @@ SlaveTimeLimitCmd(
 		    return TCL_ERROR;
 		}
 		if (tmp < 0) {
-		    Tcl_AppendResult(interp, "milliseconds must be at least 0",
-			    NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "milliseconds must be at least 0", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP",
 			    "BADVALUE", NULL);
 		    return TCL_ERROR;
 		}
-		limitMoment.usec = ((long)tmp)*1000;
+		limitMoment.usec = ((long) tmp)*1000;
 		break;
 	    case OPT_SEC:
 		secObj = objv[i+1];
@@ -4695,8 +4700,8 @@ SlaveTimeLimitCmd(
 		    return TCL_ERROR;
 		}
 		if (tmp < 0) {
-		    Tcl_AppendResult(interp, "seconds must be at least 0",
-			    NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "seconds must be at least 0", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP",
 			    "BADVALUE", NULL);
 		    return TCL_ERROR;
@@ -4713,15 +4718,17 @@ SlaveTimeLimitCmd(
 		 */
 
 		if (secObj != NULL && secLen == 0 && milliLen > 0) {
-		    Tcl_AppendResult(interp, "may only set -milliseconds "
-			    "if -seconds is not also being reset", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "may only set -milliseconds if -seconds is not "
+			    "also being reset", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP",
 			    "BADUSAGE", NULL);
 		    return TCL_ERROR;
 		}
 		if (milliLen == 0 && (secObj == NULL || secLen > 0)) {
-		    Tcl_AppendResult(interp, "may only reset -milliseconds "
-			    "if -seconds is also being reset", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "may only reset -milliseconds if -seconds is "
+			    "also being reset", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "INTERP",
 			    "BADUSAGE", NULL);
 		    return TCL_ERROR;
diff --git a/generic/tclLoad.c b/generic/tclLoad.c
index ce4d6a4..3fead6f 100644
--- a/generic/tclLoad.c
+++ b/generic/tclLoad.c
@@ -157,9 +157,8 @@ Tcl_LoadObjCmd(
 	}
     }
     if ((fullFileName[0] == 0) && (packageName == NULL)) {
-	Tcl_SetResult(interp,
-		"must specify either file name or package name",
-		TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"must specify either file name or package name", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LOAD", "NOLIBRARY",
 		NULL);
 	code = TCL_ERROR;
@@ -225,9 +224,9 @@ Tcl_LoadObjCmd(
 	     * Can't have two different packages loaded from the same file.
 	     */
 
-	    Tcl_AppendResult(interp, "file \"", fullFileName,
-		    "\" is already loaded for package \"",
-		    pkgPtr->packageName, "\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "file \"%s\" is already loaded for package \"%s\"",
+		    fullFileName, pkgPtr->packageName));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LOAD",
 		    "SPLITPERSONALITY", NULL);
 	    code = TCL_ERROR;
@@ -263,8 +262,8 @@ Tcl_LoadObjCmd(
 	 */
 
 	if (fullFileName[0] == 0) {
-	    Tcl_AppendResult(interp, "package \"", packageName,
-		    "\" isn't loaded statically", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "package \"%s\" isn't loaded statically", packageName));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LOAD", "NOTSTATIC",
 		    NULL);
 	    code = TCL_ERROR;
@@ -321,9 +320,9 @@ Tcl_LoadObjCmd(
 		}
 		if (p == pkgGuess) {
 		    Tcl_DecrRefCount(splitPtr);
-		    Tcl_AppendResult(interp,
-			    "couldn't figure out package name for ",
-			    fullFileName, NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			    "couldn't figure out package name for %s",
+			    fullFileName));
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LOAD",
 			    "WHATPACKAGE", NULL);
 		    code = TCL_ERROR;
@@ -418,9 +417,9 @@ Tcl_LoadObjCmd(
 
     if (Tcl_IsSafe(target)) {
 	if (pkgPtr->safeInitProc == NULL) {
-	    Tcl_AppendResult(interp,
-		    "can't use package in a safe interpreter: no ",
-		    pkgPtr->packageName, "_SafeInit procedure", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "can't use package in a safe interpreter: no"
+		    " %s_SafeInit procedure", pkgPtr->packageName));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LOAD", "UNSAFE",
 		    NULL);
 	    code = TCL_ERROR;
@@ -429,9 +428,9 @@ Tcl_LoadObjCmd(
 	code = pkgPtr->safeInitProc(target);
     } else {
 	if (pkgPtr->initProc == NULL) {
-	    Tcl_AppendResult(interp,
-		    "can't attach package to interpreter: no ",
-		    pkgPtr->packageName, "_Init procedure", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "can't attach package to interpreter: no %s_Init procedure",
+		    pkgPtr->packageName));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "LOAD", "ENTRYPOINT",
 		    NULL);
 	    code = TCL_ERROR;
@@ -581,9 +580,8 @@ Tcl_UnloadObjCmd(
 	}
     }
     if ((fullFileName[0] == 0) && (packageName == NULL)) {
-	Tcl_SetResult(interp,
-		"must specify either file name or package name",
-		TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"must specify either file name or package name", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "UNLOAD", "NOLIBRARY",
 		NULL);
 	code = TCL_ERROR;
@@ -655,8 +653,9 @@ Tcl_UnloadObjCmd(
 	 * It's an error to try unload a static package.
 	 */
 
-	Tcl_AppendResult(interp, "package \"", packageName,
-		"\" is loaded statically and cannot be unloaded", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"package \"%s\" is loaded statically and cannot be unloaded",
+		packageName));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "UNLOAD", "STATIC",
 		NULL);
 	code = TCL_ERROR;
@@ -667,8 +666,8 @@ Tcl_UnloadObjCmd(
 	 * The DLL pointed by the provided filename has never been loaded.
 	 */
 
-	Tcl_AppendResult(interp, "file \"", fullFileName,
-		"\" has never been loaded", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"file \"%s\" has never been loaded", fullFileName));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "UNLOAD", "NEVERLOADED",
 		NULL);
 	code = TCL_ERROR;
@@ -696,8 +695,9 @@ Tcl_UnloadObjCmd(
 	 * The package has not been loaded in this interpreter.
 	 */
 
-	Tcl_AppendResult(interp, "file \"", fullFileName,
-		"\" has never been loaded in this interpreter", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"file \"%s\" has never been loaded in this interpreter",
+		fullFileName));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "UNLOAD", "NEVERLOADED",
 		NULL);
 	code = TCL_ERROR;
@@ -712,8 +712,9 @@ Tcl_UnloadObjCmd(
 
     if (Tcl_IsSafe(target)) {
 	if (pkgPtr->safeUnloadProc == NULL) {
-	    Tcl_AppendResult(interp, "file \"", fullFileName,
-		    "\" cannot be unloaded under a safe interpreter", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "file \"%s\" cannot be unloaded under a safe interpreter",
+		    fullFileName));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "UNLOAD", "CANNOT",
 		    NULL);
 	    code = TCL_ERROR;
@@ -722,8 +723,9 @@ Tcl_UnloadObjCmd(
 	unloadProc = pkgPtr->safeUnloadProc;
     } else {
 	if (pkgPtr->unloadProc == NULL) {
-	    Tcl_AppendResult(interp, "file \"", fullFileName,
-		    "\" cannot be unloaded under a trusted interpreter", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "file \"%s\" cannot be unloaded under a trusted interpreter",
+		    fullFileName));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "UNLOAD", "CANNOT",
 		    NULL);
 	    code = TCL_ERROR;
@@ -862,8 +864,9 @@ Tcl_UnloadObjCmd(
 	    }
 	}
 #else
-	Tcl_AppendResult(interp, "file \"", fullFileName,
-		"\" cannot be unloaded: unloading disabled", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"file \"%s\" cannot be unloaded: unloading disabled",
+		fullFileName));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "UNLOAD", "DISABLED",
 		NULL);
 	code = TCL_ERROR;
diff --git a/generic/tclLoadNone.c b/generic/tclLoadNone.c
index ac094e6..6b48aee 100644
--- a/generic/tclLoadNone.c
+++ b/generic/tclLoadNone.c
@@ -44,9 +44,9 @@ TclpDlopen(
 				 * function which should be used for this
 				 * file. */
 {
-    Tcl_SetResult(interp,
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 	    "dynamic loading is not currently available on this system",
-	    TCL_STATIC);
+	    -1));
     return TCL_ERROR;
 }
 
diff --git a/generic/tclNamesp.c b/generic/tclNamesp.c
index 6a241f0..3c93400 100644
--- a/generic/tclNamesp.c
+++ b/generic/tclNamesp.c
@@ -687,9 +687,8 @@ Tcl_CreateNamespace(
 	parentPtr = NULL;
 	simpleName = "";
     } else if (*name == '\0') {
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "can't create namespace \"\": "
-		"only global namespace can have empty name", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj("can't create namespace"
+                " \"\": only global namespace can have empty name", -1));
         Tcl_SetErrorCode(interp, "TCL", "OPERATION", "NAMESPACE",
                 "CREATEGLOBAL", NULL);
 	return NULL;
@@ -725,8 +724,8 @@ Tcl_CreateNamespace(
 	    Tcl_FindHashEntry(parentPtr->childTablePtr, simpleName) != NULL
 #endif
 	) {
-	    Tcl_AppendResult(interp, "can't create namespace \"", name,
-		    "\": already exists", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "can't create namespace \"%s\": already exists", name));
             Tcl_SetErrorCode(interp, "TCL", "OPERATION", "NAMESPACE",
                     "CREATEEXISTING", NULL);
 	    return NULL;
@@ -1336,8 +1335,8 @@ Tcl_Export(
 	    &exportNsPtr, &dummyPtr, &dummyPtr, &simplePattern);
 
     if ((exportNsPtr != nsPtr) || (strcmp(pattern, simplePattern) != 0)) {
-	Tcl_AppendResult(interp, "invalid export pattern \"", pattern,
-		"\": pattern can't specify a namespace", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf("invalid export pattern"
+                " \"%s\": pattern can't specify a namespace", pattern));
         Tcl_SetErrorCode(interp, "TCL", "EXPORT", "INVALID", NULL);
 	return TCL_ERROR;
     }
@@ -1551,21 +1550,21 @@ Tcl_Import(
 	    &importNsPtr, &dummyPtr, &dummyPtr, &simplePattern);
 
     if (importNsPtr == NULL) {
-	Tcl_AppendResult(interp, "unknown namespace in import pattern \"",
-		pattern, "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "unknown namespace in import pattern \"%s\"", pattern));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "NAMESPACE", pattern, NULL);
 	return TCL_ERROR;
     }
     if (importNsPtr == nsPtr) {
 	if (pattern == simplePattern) {
-	    Tcl_AppendResult(interp,
-		    "no namespace specified in import pattern \"", pattern,
-		    "\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "no namespace specified in import pattern \"%s\"",
+                    pattern));
             Tcl_SetErrorCode(interp, "TCL", "IMPORT", "ORIGIN", NULL);
 	} else {
-	    Tcl_AppendResult(interp, "import pattern \"", pattern,
-		    "\" tries to import from namespace \"",
-		    importNsPtr->name, "\" into itself", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "import pattern \"%s\" tries to import from namespace"
+                    " \"%s\" into itself", pattern, importNsPtr->name));
             Tcl_SetErrorCode(interp, "TCL", "IMPORT", "SELF", NULL);
 	}
 	return TCL_ERROR;
@@ -1684,9 +1683,10 @@ DoImport(
 		dataPtr = linkCmd->objClientData;
 		linkCmd = dataPtr->realCmdPtr;
 		if (overwrite == linkCmd) {
-		    Tcl_AppendResult(interp, "import pattern \"", pattern,
-			    "\" would create a loop containing command \"",
-			    Tcl_DStringValue(&ds), "\"", NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                            "import pattern \"%s\" would create a loop"
+                            " containing command \"%s\"",
+                            pattern, Tcl_DStringValue(&ds)));
 		    Tcl_DStringFree(&ds);
                     Tcl_SetErrorCode(interp, "TCL", "IMPORT", "LOOP", NULL);
 		    return TCL_ERROR;
@@ -1726,8 +1726,8 @@ DoImport(
 		return TCL_OK;
 	    }
 	}
-	Tcl_AppendResult(interp, "can't import command \"", cmdName,
-		"\": already exists", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't import command \"%s\": already exists", cmdName));
         Tcl_SetErrorCode(interp, "TCL", "IMPORT", "OVERWRITE", NULL);
 	return TCL_ERROR;
     }
@@ -1796,9 +1796,9 @@ Tcl_ForgetImport(
 	    &sourceNsPtr, &dummyPtr, &dummyPtr, &simplePattern);
 
     if (sourceNsPtr == NULL) {
-	Tcl_AppendResult(interp,
-		"unknown namespace in namespace forget pattern \"",
-		pattern, "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"unknown namespace in namespace forget pattern \"%s\"",
+		pattern));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "NAMESPACE", pattern, NULL);
 	return TCL_ERROR;
     }
@@ -2402,8 +2402,8 @@ Tcl_FindNamespace(
     }
 
     if (flags & TCL_LEAVE_ERR_MSG) {
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "unknown namespace \"", name, "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "unknown namespace \"%s\"", name));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "NAMESPACE", name, NULL);
     }
     return NULL;
@@ -2589,8 +2589,8 @@ Tcl_FindCommand(
     }
 
     if (flags & TCL_LEAVE_ERR_MSG) {
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "unknown command \"", name, "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "unknown command \"%s\"", name));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COMMAND", name, NULL);
     }
     return NULL;
@@ -3170,9 +3170,9 @@ NamespaceDeleteCmd(
 	namespacePtr = Tcl_FindNamespace(interp, name, NULL, /*flags*/ 0);
 	if ((namespacePtr == NULL)
 		|| (((Namespace *) namespacePtr)->flags & NS_KILLED)) {
-	    Tcl_AppendResult(interp, "unknown namespace \"",
-		    TclGetString(objv[i]),
-		    "\" in namespace delete command", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "unknown namespace \"%s\" in namespace delete command",
+		    TclGetString(objv[i])));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "NAMESPACE",
 		    TclGetString(objv[i]), NULL);
 	    return TCL_ERROR;
@@ -3834,8 +3834,8 @@ NamespaceOriginCmd(
 
     command = Tcl_GetCommandFromObj(interp, objv[1]);
     if (command == NULL) {
-	Tcl_AppendResult(interp, "invalid command name \"",
-		TclGetString(objv[1]), "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "invalid command name \"%s\"", TclGetString(objv[1])));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COMMAND",
 		TclGetString(objv[1]), NULL);
 	return TCL_ERROR;
diff --git a/generic/tclOO.c b/generic/tclOO.c
index df7d49d..d9f5d60 100644
--- a/generic/tclOO.c
+++ b/generic/tclOO.c
@@ -1582,8 +1582,9 @@ Tcl_NewObjectInstance(
 
     if (nameStr && Tcl_FindCommand(interp, nameStr, NULL,
 	    TCL_NAMESPACE_ONLY)) {
-	Tcl_AppendResult(interp, "can't create object \"", nameStr,
-		"\": command already exists with that name", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"can't create object \"%s\": command already exists with"
+		" that name", nameStr));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "OVERWRITE_OBJECT", NULL);
 	return NULL;
     }
@@ -1649,8 +1650,8 @@ Tcl_NewObjectInstance(
 	     */
 
 	    if (result != TCL_ERROR && Deleted(oPtr)) {
-		Tcl_SetResult(interp, "object deleted in constructor",
-			TCL_STATIC);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"object deleted in constructor", -1));
 		Tcl_SetErrorCode(interp, "TCL", "OO", "STILLBORN", NULL);
 		result = TCL_ERROR;
 	    }
@@ -1705,8 +1706,9 @@ TclNRNewObjectInstance(
 
     if (nameStr && Tcl_FindCommand(interp, nameStr, NULL,
 	    TCL_NAMESPACE_ONLY)) {
-	Tcl_AppendResult(interp, "can't create object \"", nameStr,
-		"\": command already exists with that name", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"can't create object \"%s\": command already exists with"
+		" that name", nameStr));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "OVERWRITE_OBJECT", NULL);
 	return TCL_ERROR;
     }
@@ -1794,7 +1796,8 @@ FinalizeAlloc(
      */
 
     if (result != TCL_ERROR && Deleted(oPtr)) {
-	Tcl_SetResult(interp, "object deleted in constructor", TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"object deleted in constructor", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "STILLBORN", NULL);
 	result = TCL_ERROR;
     }
@@ -1851,7 +1854,8 @@ Tcl_CopyObjectInstance(
      */
 
     if (IsRootClass(oPtr)) {
-	Tcl_AppendResult(interp, "may not clone the class of classes", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"may not clone the class of classes", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "CLONING_CLASS", NULL);
 	return NULL;
     }
@@ -2514,9 +2518,9 @@ TclOOObjectCmdCore(
 		flags | (oPtr->flags & FILTER_HANDLING), methodNamePtr);
 	TclDecrRefCount(mappedMethodName);
 	if (contextPtr == NULL) {
-	    Tcl_AppendResult(interp, "impossible to invoke method \"",
-		    TclGetString(methodNamePtr),
-		    "\": no defined method or unknown method", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "impossible to invoke method \"%s\": no defined method or"
+		    " unknown method", TclGetString(methodNamePtr)));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD_MAPPED",
 		    TclGetString(methodNamePtr), NULL);
 	    return TCL_ERROR;
@@ -2530,9 +2534,9 @@ TclOOObjectCmdCore(
 	contextPtr = TclOOGetCallContext(oPtr, methodNamePtr,
 		flags | (oPtr->flags & FILTER_HANDLING), NULL);
 	if (contextPtr == NULL) {
-	    Tcl_AppendResult(interp, "impossible to invoke method \"",
-		    TclGetString(methodNamePtr),
-		    "\": no defined method or unknown method", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "impossible to invoke method \"%s\": no defined method or"
+		    " unknown method", TclGetString(methodNamePtr)));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		    TclGetString(methodNamePtr), NULL);
 	    return TCL_ERROR;
@@ -2558,8 +2562,8 @@ TclOOObjectCmdCore(
 	    }
 	}
 	if (contextPtr->index >= contextPtr->callPtr->numChain) {
-	    Tcl_SetResult(interp, "no valid method implementation",
-		    TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "no valid method implementation", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		    TclGetString(methodNamePtr), NULL);
 	    TclOODeleteContext(contextPtr);
@@ -2640,8 +2644,8 @@ Tcl_ObjectContextInvokeNext(
 	    methodType = "method";
 	}
 
-	Tcl_AppendResult(interp, "no next ", methodType, " implementation",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"no next %s implementation", methodType));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "NOTHING_NEXT", NULL);
 	return TCL_ERROR;
     }
@@ -2709,8 +2713,8 @@ TclNRObjectContextInvokeNext(
 	    methodType = "method";
 	}
 
-	Tcl_AppendResult(interp, "no next ", methodType, " implementation",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"no next %s implementation", methodType));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "NOTHING_NEXT", NULL);
 	return TCL_ERROR;
     }
@@ -2787,8 +2791,8 @@ Tcl_GetObjectFromObj(
     return cmdPtr->objClientData;
 
   notAnObject:
-    Tcl_AppendResult(interp, TclGetString(objPtr),
-	    " does not refer to an object", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "%s does not refer to an object", TclGetString(objPtr)));
     Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "OBJECT", TclGetString(objPtr),
 	    NULL);
     return NULL;
diff --git a/generic/tclOOBasic.c b/generic/tclOOBasic.c
index 35ad1eb..3637ede 100644
--- a/generic/tclOOBasic.c
+++ b/generic/tclOOBasic.c
@@ -168,8 +168,8 @@ TclOO_Class_Create(
     if (oPtr->classPtr == NULL) {
 	Tcl_Obj *cmdnameObj = TclOOObjectName(interp, oPtr);
 
-	Tcl_AppendResult(interp, "object \"", TclGetString(cmdnameObj),
-		"\" is not a class", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"object \"%s\" is not a class", TclGetString(cmdnameObj)));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "INSTANTIATE_NONCLASS", NULL);
 	return TCL_ERROR;
     }
@@ -186,7 +186,8 @@ TclOO_Class_Create(
     objName = Tcl_GetStringFromObj(
 	    objv[Tcl_ObjectContextSkippedArgs(context)], &len);
     if (len == 0) {
-	Tcl_AppendResult(interp, "object name must not be empty", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"object name must not be empty", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "EMPTY_NAME", NULL);
 	return TCL_ERROR;
     }
@@ -232,8 +233,8 @@ TclOO_Class_CreateNs(
     if (oPtr->classPtr == NULL) {
 	Tcl_Obj *cmdnameObj = TclOOObjectName(interp, oPtr);
 
-	Tcl_AppendResult(interp, "object \"", TclGetString(cmdnameObj),
-		"\" is not a class", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"object \"%s\" is not a class", TclGetString(cmdnameObj)));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "INSTANTIATE_NONCLASS", NULL);
 	return TCL_ERROR;
     }
@@ -250,14 +251,16 @@ TclOO_Class_CreateNs(
     objName = Tcl_GetStringFromObj(
 	    objv[Tcl_ObjectContextSkippedArgs(context)], &len);
     if (len == 0) {
-	Tcl_AppendResult(interp, "object name must not be empty", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"object name must not be empty", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "EMPTY_NAME", NULL);
 	return TCL_ERROR;
     }
     nsName = Tcl_GetStringFromObj(
 	    objv[Tcl_ObjectContextSkippedArgs(context)+1], &len);
     if (len == 0) {
-	Tcl_AppendResult(interp, "namespace name must not be empty", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"namespace name must not be empty", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "EMPTY_NAME", NULL);
 	return TCL_ERROR;
     }
@@ -301,8 +304,8 @@ TclOO_Class_New(
     if (oPtr->classPtr == NULL) {
 	Tcl_Obj *cmdnameObj = TclOOObjectName(interp, oPtr);
 
-	Tcl_AppendResult(interp, "object \"", TclGetString(cmdnameObj),
-		"\" is not a class", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"object \"%s\" is not a class", TclGetString(cmdnameObj)));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "INSTANTIATE_NONCLASS", NULL);
 	return TCL_ERROR;
     }
@@ -504,6 +507,7 @@ TclOO_Object_Unknown(
     Object *oPtr = contextPtr->oPtr;
     const char **methodNames;
     int numMethodNames, i, skip = Tcl_ObjectContextSkippedArgs(context);
+    Tcl_Obj *errorMsg;
 
     /*
      * If no method name, generate an error asking for a method name. (Only by
@@ -529,31 +533,34 @@ TclOO_Object_Unknown(
 
     if (numMethodNames == 0) {
 	Tcl_Obj *tmpBuf = TclOOObjectName(interp, oPtr);
+	const char *piece;
 
-	Tcl_AppendResult(interp, "object \"", TclGetString(tmpBuf), NULL);
 	if (contextPtr->callPtr->flags & PUBLIC_METHOD) {
-	    Tcl_AppendResult(interp, "\" has no visible methods", NULL);
+	    piece = "visible methods";
 	} else {
-	    Tcl_AppendResult(interp, "\" has no methods", NULL);
+	    piece = "methods";
 	}
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"object \"%s\" has no %s", TclGetString(tmpBuf), piece));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		TclGetString(objv[skip]), NULL);
 	return TCL_ERROR;
     }
 
-    Tcl_AppendResult(interp, "unknown method \"", TclGetString(objv[skip]),
-	    "\": must be ", NULL);
+    errorMsg = Tcl_ObjPrintf("unknown method \"%s\": must be ",
+	    TclGetString(objv[skip]));
     for (i=0 ; i<numMethodNames-1 ; i++) {
 	if (i) {
-	    Tcl_AppendResult(interp, ", ", NULL);
+	    Tcl_AppendToObj(errorMsg, ", ", -1);
 	}
-	Tcl_AppendResult(interp, methodNames[i], NULL);
+	Tcl_AppendToObj(errorMsg, methodNames[i], -1);
     }
     if (i) {
-	Tcl_AppendResult(interp, " or ", NULL);
+	Tcl_AppendToObj(errorMsg, " or ", -1);
     }
-    Tcl_AppendResult(interp, methodNames[i], NULL);
+    Tcl_AppendToObj(errorMsg, methodNames[i], -1);
     ckfree(methodNames);
+    Tcl_SetObjResult(interp, errorMsg);
     Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 	    TclGetString(objv[skip]), NULL);
     return TCL_ERROR;
@@ -609,8 +616,9 @@ TclOO_Object_LinkVar(
 	 */
 
 	if (strstr(varName, "::") != NULL) {
-	    Tcl_AppendResult(interp, "variable name \"", varName,
-		    "\" illegal: must not contain namespace separator", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "variable name \"%s\" illegal: must not contain namespace"
+		    " separator", varName));
 	    Tcl_SetErrorCode(interp, "TCL", "UPVAR", "INVERTED", NULL);
 	    return TCL_ERROR;
 	}
@@ -784,8 +792,9 @@ TclOONextObjCmd(
      */
 
     if (framePtr == NULL || !(framePtr->isProcCallFrame & FRAME_IS_METHOD)) {
-	Tcl_AppendResult(interp, TclGetString(objv[0]),
-		" may only be called from inside a method", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"%s may only be called from inside a method",
+		TclGetString(objv[0])));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "CONTEXT_REQUIRED", NULL);
 	return TCL_ERROR;
     }
@@ -822,8 +831,9 @@ TclOONextToObjCmd(
      */
 
     if (framePtr == NULL || !(framePtr->isProcCallFrame & FRAME_IS_METHOD)) {
-	Tcl_AppendResult(interp, TclGetString(objv[0]),
-		" may only be called from inside a method", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"%s may only be called from inside a method",
+		TclGetString(objv[0])));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "CONTEXT_REQUIRED", NULL);
 	return TCL_ERROR;
     }
@@ -843,8 +853,9 @@ TclOONextToObjCmd(
     }
     classPtr = ((Object *)object)->classPtr;
     if (classPtr == NULL) {
-	Tcl_AppendResult(interp, "\"", TclGetString(objv[1]),
-		"\" is not a class", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"\"%s\" is not a class", TclGetString(objv[1])));
+	Tcl_SetErrorCode(interp, "TCL", "OO", "CLASS_REQUIRED", NULL);
 	return TCL_ERROR;
     }
 
@@ -881,14 +892,15 @@ TclOONextToObjCmd(
 	struct MInvoke *miPtr = contextPtr->callPtr->chain + i;
 
 	if (!miPtr->isFilter && miPtr->mPtr->declaringClassPtr == classPtr) {
-	    Tcl_AppendResult(interp, "method implementation by \"",
-		    TclGetString(objv[1]), "\" not reachable from here",
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "method implementation by \"%s\" not reachable from here",
+		    TclGetString(objv[1])));
 	    return TCL_ERROR;
 	}
     }
-    Tcl_AppendResult(interp, "method has no non-filter implementation by \"",
-	    TclGetString(objv[1]), "\"", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "method has no non-filter implementation by \"%s\"",
+	    TclGetString(objv[1])));
     return TCL_ERROR;
 }
 
@@ -948,8 +960,9 @@ TclOOSelfObjCmd(
      */
 
     if (framePtr == NULL || !(framePtr->isProcCallFrame & FRAME_IS_METHOD)) {
-	Tcl_AppendResult(interp, TclGetString(objv[0]),
-		" may only be called from inside a method", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"%s may only be called from inside a method",
+		TclGetString(objv[0])));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "CONTEXT_REQUIRED", NULL);
 	return TCL_ERROR;
     }
@@ -983,7 +996,8 @@ TclOOSelfObjCmd(
 	Class *clsPtr = CurrentlyInvoked(contextPtr).mPtr->declaringClassPtr;
 
 	if (clsPtr == NULL) {
-	    Tcl_AppendResult(interp, "method not defined by a class", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "method not defined by a class", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "UNMATCHED_CONTEXT", NULL);
 	    return TCL_ERROR;
 	}
@@ -1003,7 +1017,8 @@ TclOOSelfObjCmd(
 	return TCL_OK;
     case SELF_FILTER:
 	if (!CurrentlyInvoked(contextPtr).isFilter) {
-	    Tcl_AppendResult(interp, "not inside a filtering context", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "not inside a filtering context", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "UNMATCHED_CONTEXT", NULL);
 	    return TCL_ERROR;
 	} else {
@@ -1028,7 +1043,8 @@ TclOOSelfObjCmd(
     case SELF_CALLER:
 	if ((framePtr->callerVarPtr == NULL) ||
 		!(framePtr->callerVarPtr->isProcCallFrame & FRAME_IS_METHOD)){
-	    Tcl_AppendResult(interp, "caller is not an object", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "caller is not an object", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "CONTEXT_REQUIRED", NULL);
 	    return TCL_ERROR;
 	} else {
@@ -1045,7 +1061,8 @@ TclOOSelfObjCmd(
 		 * This should be unreachable code.
 		 */
 
-		Tcl_AppendResult(interp, "method without declarer!", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"method without declarer!", -1));
 		return TCL_ERROR;
 	    }
 
@@ -1076,7 +1093,8 @@ TclOOSelfObjCmd(
 		 * This should be unreachable code.
 		 */
 
-		Tcl_AppendResult(interp, "method without declarer!", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"method without declarer!", -1));
 		return TCL_ERROR;
 	    }
 
@@ -1093,7 +1111,8 @@ TclOOSelfObjCmd(
 	return TCL_OK;
     case SELF_TARGET:
 	if (!CurrentlyInvoked(contextPtr).isFilter) {
-	    Tcl_AppendResult(interp, "not inside a filtering context", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "not inside a filtering context", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "UNMATCHED_CONTEXT", NULL);
 	    return TCL_ERROR;
 	} else {
@@ -1119,7 +1138,8 @@ TclOOSelfObjCmd(
 		 * This should be unreachable code.
 		 */
 
-		Tcl_AppendResult(interp, "method without declarer!", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"method without declarer!", -1));
 		return TCL_ERROR;
 	    }
 	    result[0] = TclOOObjectName(interp, declarerPtr);
diff --git a/generic/tclOODefineCmds.c b/generic/tclOODefineCmds.c
index 69cffb0..c022e6b 100644
--- a/generic/tclOODefineCmds.c
+++ b/generic/tclOODefineCmds.c
@@ -423,8 +423,8 @@ RenameDeleteMethod(
     if (!useClass) {
 	if (!oPtr->methodsPtr) {
 	noSuchMethod:
-	    Tcl_AppendResult(interp, "method ", TclGetString(fromPtr),
-		    " does not exist", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "method %s does not exist", TclGetString(fromPtr)));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		    TclGetString(fromPtr), NULL);
 	    return TCL_ERROR;
@@ -438,14 +438,15 @@ RenameDeleteMethod(
 		    &isNew);
 	    if (hPtr == newHPtr) {
 	    renameToSelf:
-		Tcl_AppendResult(interp, "cannot rename method to itself",
-			NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"cannot rename method to itself", -1));
 		Tcl_SetErrorCode(interp, "TCL", "OO", "RENAME_TO_SELF", NULL);
 		return TCL_ERROR;
 	    } else if (!isNew) {
 	    renameToExisting:
-		Tcl_AppendResult(interp, "method called ",
-			TclGetString(toPtr), " already exists", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"method called %s already exists",
+			TclGetString(toPtr)));
 		Tcl_SetErrorCode(interp, "TCL", "OO", "RENAME_OVER", NULL);
 		return TCL_ERROR;
 	    }
@@ -513,7 +514,8 @@ TclOOUnknownDefinition(
     const char *soughtStr, *matchedStr = NULL;
 
     if (objc < 2) {
-	Tcl_AppendResult(interp, "bad call of unknown handler", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"bad call of unknown handler", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "BAD_UNKNOWN", NULL);
 	return TCL_ERROR;
     }
@@ -558,7 +560,8 @@ TclOOUnknownDefinition(
     }
 
   noMatch:
-    Tcl_AppendResult(interp, "invalid command name \"",soughtStr,"\"", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "invalid command name \"%s\"", soughtStr));
     Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COMMAND", soughtStr, NULL);
     return TCL_ERROR;
 }
@@ -646,9 +649,9 @@ InitDefineContext(
     int result;
 
     if (namespacePtr == NULL) {
-	Tcl_AppendResult(interp,
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		"cannot process definitions; support namespace deleted",
-		NULL);
+		-1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -686,16 +689,17 @@ TclOOGetDefineCmdContext(
 
     if ((iPtr->varFramePtr == NULL)
 	    || (iPtr->varFramePtr->isProcCallFrame != FRAME_IS_OO_DEFINE)) {
-	Tcl_AppendResult(interp, "this command may only be called from within"
-		" the context of an ::oo::define or ::oo::objdefine command",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"this command may only be called from within the context of"
+		" an ::oo::define or ::oo::objdefine command", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return NULL;
     }
     object = iPtr->varFramePtr->clientData;
     if (Tcl_ObjectDeleted(object)) {
-	Tcl_AppendResult(interp, "this command cannot be called when the "
-		"object has been deleted", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"this command cannot be called when the object has been"
+		" deleted", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return NULL;
     }
@@ -736,7 +740,7 @@ GetClassInOuterContext(
 	return NULL;
     }
     if (oPtr->classPtr == NULL) {
-	Tcl_AppendResult(interp, errMsg, NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(errMsg, -1));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "CLASS",
 		TclGetString(className), NULL);
 	return NULL;
@@ -816,8 +820,8 @@ TclOODefineObjCmd(
 	return TCL_ERROR;
     }
     if (oPtr->classPtr == NULL) {
-	Tcl_AppendResult(interp, TclGetString(objv[1]),
-		" does not refer to a class", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"%s does not refer to a class",TclGetString(objv[1])));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "CLASS",
 		TclGetString(objv[1]), NULL);
 	return TCL_ERROR;
@@ -1161,14 +1165,14 @@ TclOODefineClassObjCmd(
 	return TCL_ERROR;
     }
     if (oPtr->flags & ROOT_OBJECT) {
-	Tcl_AppendResult(interp,
-		"may not modify the class of the root object class", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"may not modify the class of the root object class", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
     if (oPtr->flags & ROOT_CLASS) {
-	Tcl_AppendResult(interp,
-		"may not modify the class of the class of classes", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"may not modify the class of the class of classes", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -1194,9 +1198,10 @@ TclOODefineClassObjCmd(
      */
 
     if ((oPtr->classPtr==NULL) == TclOOIsReachable(fPtr->classCls, clsPtr)) {
-	Tcl_AppendResult(interp, "may not change a ",
-		(oPtr->classPtr==NULL ? "non-" : ""), "class object into a ",
-		(oPtr->classPtr==NULL ? "" : "non-"), "class object", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"may not change a %sclass object into a %sclass object",
+		(oPtr->classPtr==NULL ? "non-" : ""),
+		(oPtr->classPtr==NULL ? "" : "non-")));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "TRANSMUTATION", NULL);
 	return TCL_ERROR;
     }
@@ -1317,7 +1322,8 @@ TclOODefineDeleteMethodObjCmd(
 	return TCL_ERROR;
     }
     if (!isInstanceDeleteMethod && !oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -1440,7 +1446,8 @@ TclOODefineExportObjCmd(
     }
     clsPtr = oPtr->classPtr;
     if (!isInstanceExport && !clsPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -1531,7 +1538,8 @@ TclOODefineForwardObjCmd(
 	return TCL_ERROR;
     }
     if (!isInstanceForward && !oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -1588,7 +1596,8 @@ TclOODefineMethodObjCmd(
 	return TCL_ERROR;
     }
     if (!isInstanceMethod && !oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -1639,7 +1648,8 @@ TclOODefineMixinObjCmd(
 	return TCL_ERROR;
     }
     if (!isInstanceMixin && !oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -1653,7 +1663,8 @@ TclOODefineMixinObjCmd(
 	    goto freeAndError;
 	}
 	if (!isInstanceMixin && TclOOIsReachable(oPtr->classPtr, clsPtr)) {
-	    Tcl_AppendResult(interp, "may not mix a class into itself", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "may not mix a class into itself", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "SELF_MIXIN", NULL);
 	    goto freeAndError;
 	}
@@ -1704,7 +1715,8 @@ TclOODefineRenameMethodObjCmd(
 	return TCL_ERROR;
     }
     if (!isInstanceRenameMethod && !oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -1764,7 +1776,8 @@ TclOODefineUnexportObjCmd(
     }
     clsPtr = oPtr->classPtr;
     if (!isInstanceUnexport && !clsPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -1949,7 +1962,8 @@ ClassFilterGet(
     if (oPtr == NULL) {
 	return TCL_ERROR;
     } else if (!oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -1984,7 +1998,8 @@ ClassFilterSet(
     if (oPtr == NULL) {
 	return TCL_ERROR;
     } else if (!oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     } else if (Tcl_ListObjGetElements(interp, objv[0], &filterc,
@@ -2027,7 +2042,8 @@ ClassMixinGet(
     if (oPtr == NULL) {
 	return TCL_ERROR;
     } else if (!oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -2065,7 +2081,8 @@ ClassMixinSet(
     if (oPtr == NULL) {
 	return TCL_ERROR;
     } else if (!oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     } else if (Tcl_ListObjGetElements(interp, objv[0], &mixinc,
@@ -2082,7 +2099,8 @@ ClassMixinSet(
 	    goto freeAndError;
 	}
 	if (TclOOIsReachable(oPtr->classPtr, mixins[i])) {
-	    Tcl_AppendResult(interp, "may not mix a class into itself", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "may not mix a class into itself", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "SELF_MIXIN", NULL);
 	    goto freeAndError;
 	}
@@ -2128,7 +2146,8 @@ ClassSuperGet(
     if (oPtr == NULL) {
 	return TCL_ERROR;
     } else if (!oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -2165,12 +2184,13 @@ ClassSuperSet(
     if (oPtr == NULL) {
 	return TCL_ERROR;
     } else if (!oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     } else if (oPtr == oPtr->fPtr->objectCls->thisPtr) {
-	Tcl_AppendResult(interp,
-		"may not modify the superclass of the root object", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"may not modify the superclass of the root object", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     } else if (Tcl_ListObjGetElements(interp, objv[0], &superc,
@@ -2196,15 +2216,15 @@ ClassSuperSet(
 	}
 	for (j=0 ; j<i ; j++) {
 	    if (superclasses[j] == superclasses[i]) {
-		Tcl_AppendResult(interp,
-			"class should only be a direct superclass once",NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"class should only be a direct superclass once", -1));
 		Tcl_SetErrorCode(interp, "TCL", "OO", "REPETITIOUS", NULL);
 		goto failedAfterAlloc;
 	    }
 	}
 	if (TclOOIsReachable(oPtr->classPtr, superclasses[i])) {
-	    Tcl_AppendResult(interp,
-		    "attempt to form circular dependency graph", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "attempt to form circular dependency graph", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "CIRCULARITY", NULL);
 	failedAfterAlloc:
 	    ckfree((char *) superclasses);
@@ -2265,7 +2285,8 @@ ClassVarsGet(
     if (oPtr == NULL) {
 	return TCL_ERROR;
     } else if (!oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     }
@@ -2301,7 +2322,8 @@ ClassVarsSet(
     if (oPtr == NULL) {
 	return TCL_ERROR;
     } else if (!oPtr->classPtr) {
-	Tcl_AppendResult(interp, "attempt to misuse API", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to misuse API", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "MONKEY_BUSINESS", NULL);
 	return TCL_ERROR;
     } else if (Tcl_ListObjGetElements(interp, objv[0], &varc,
@@ -2313,15 +2335,16 @@ ClassVarsSet(
 	const char *varName = Tcl_GetString(varv[i]);
 
 	if (strstr(varName, "::") != NULL) {
-	    Tcl_AppendResult(interp, "invalid declared variable name \"",
-		    varName, "\": must not contain namespace separators",
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "invalid declared variable name \"%s\": must not %s",
+		    varName, "contain namespace separators"));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "BAD_DECLVAR", NULL);
 	    return TCL_ERROR;
 	}
 	if (Tcl_StringMatch(varName, "*(*)")) {
-	    Tcl_AppendResult(interp, "invalid declared variable name \"",
-		    varName, "\": must not refer to an array element", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "invalid declared variable name \"%s\": must not %s",
+		    varName, "refer to an array element"));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "BAD_DECLVAR", NULL);
 	    return TCL_ERROR;
 	}
@@ -2591,15 +2614,16 @@ ObjVarsSet(
 	const char *varName = Tcl_GetString(varv[i]);
 
 	if (strstr(varName, "::") != NULL) {
-	    Tcl_AppendResult(interp, "invalid declared variable name \"",
-		    varName, "\": must not contain namespace separators",
-		    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "invalid declared variable name \"%s\": must not %s",
+		    varName, "contain namespace separators"));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "BAD_DECLVAR", NULL);
 	    return TCL_ERROR;
 	}
 	if (Tcl_StringMatch(varName, "*(*)")) {
-	    Tcl_AppendResult(interp, "invalid declared variable name \"",
-		    varName, "\": must not refer to an array element", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "invalid declared variable name \"%s\": must not %s",
+		    varName, "refer to an array element"));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "BAD_DECLVAR", NULL);
 	    return TCL_ERROR;
 	}
diff --git a/generic/tclOOInfo.c b/generic/tclOOInfo.c
index f298320..796442b 100644
--- a/generic/tclOOInfo.c
+++ b/generic/tclOOInfo.c
@@ -177,8 +177,8 @@ GetClassFromObj(
 	return NULL;
     }
     if (oPtr->classPtr == NULL) {
-	Tcl_AppendResult(interp, "\"", TclGetString(objPtr),
-		"\" is not a class", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"\"%s\" is not a class", TclGetString(objPtr)));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "CLASS",
 		TclGetString(objPtr), NULL);
 	return NULL;
@@ -279,16 +279,16 @@ InfoObjectDefnCmd(
     hPtr = Tcl_FindHashEntry(oPtr->methodsPtr, (char *) objv[2]);
     if (hPtr == NULL) {
     unknownMethod:
-	Tcl_AppendResult(interp, "unknown method \"", TclGetString(objv[2]),
-		"\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"unknown method \"%s\"", TclGetString(objv[2])));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		TclGetString(objv[2]), NULL);
 	return TCL_ERROR;
     }
     procPtr = TclOOGetProcFromMethod(Tcl_GetHashValue(hPtr));
     if (procPtr == NULL) {
-	Tcl_AppendResult(interp,
-		"definition not available for this kind of method", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"definition not available for this kind of method", -1));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		TclGetString(objv[2]), NULL);
 	return TCL_ERROR;
@@ -390,17 +390,17 @@ InfoObjectForwardCmd(
     hPtr = Tcl_FindHashEntry(oPtr->methodsPtr, (char *) objv[2]);
     if (hPtr == NULL) {
     unknownMethod:
-	Tcl_AppendResult(interp, "unknown method \"", TclGetString(objv[2]),
-		"\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"unknown method \"%s\"", TclGetString(objv[2])));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		TclGetString(objv[2]), NULL);
 	return TCL_ERROR;
     }
     prefixObj = TclOOGetFwdFromMethod(Tcl_GetHashValue(hPtr));
     if (prefixObj == NULL) {
-	Tcl_AppendResult(interp,
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		"prefix argument list not available for this kind of method",
-		NULL);
+		-1));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		TclGetString(objv[2]), NULL);
 	return TCL_ERROR;
@@ -491,7 +491,8 @@ InfoObjectIsACmd(
 	    return TCL_ERROR;
 	}
 	if (o2Ptr->classPtr == NULL) {
-	    Tcl_AppendResult(interp, "non-classes cannot be mixins", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "non-classes cannot be mixins", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "NONCLASS", NULL);
 	    return TCL_ERROR;
 	} else {
@@ -516,7 +517,8 @@ InfoObjectIsACmd(
 	    return TCL_ERROR;
 	}
 	if (o2Ptr->classPtr == NULL) {
-	    Tcl_AppendResult(interp, "non-classes cannot be types", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "non-classes cannot be types", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "NONCLASS", NULL);
 	    return TCL_ERROR;
 	}
@@ -651,8 +653,8 @@ InfoObjectMethodTypeCmd(
     hPtr = Tcl_FindHashEntry(oPtr->methodsPtr, (char *) objv[2]);
     if (hPtr == NULL) {
     unknownMethod:
-	Tcl_AppendResult(interp, "unknown method \"", TclGetString(objv[2]),
-		"\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"unknown method \"%s\"", TclGetString(objv[2])));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		TclGetString(objv[2]), NULL);
 	return TCL_ERROR;
@@ -878,8 +880,8 @@ InfoClassConstrCmd(
     }
     procPtr = TclOOGetProcFromMethod(clsPtr->constructorPtr);
     if (procPtr == NULL) {
-	Tcl_AppendResult(interp,
-		"definition not available for this kind of method", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"definition not available for this kind of method", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "METHOD_TYPE", NULL);
 	return TCL_ERROR;
     }
@@ -937,16 +939,16 @@ InfoClassDefnCmd(
     }
     hPtr = Tcl_FindHashEntry(&clsPtr->classMethods, (char *) objv[2]);
     if (hPtr == NULL) {
-	Tcl_AppendResult(interp, "unknown method \"", TclGetString(objv[2]),
-		"\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"unknown method \"%s\"", TclGetString(objv[2])));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		TclGetString(objv[2]), NULL);
 	return TCL_ERROR;
     }
     procPtr = TclOOGetProcFromMethod(Tcl_GetHashValue(hPtr));
     if (procPtr == NULL) {
-	Tcl_AppendResult(interp,
-		"definition not available for this kind of method", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"definition not available for this kind of method", -1));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		TclGetString(objv[2]), NULL);
 	return TCL_ERROR;
@@ -1006,8 +1008,8 @@ InfoClassDestrCmd(
     }
     procPtr = TclOOGetProcFromMethod(clsPtr->destructorPtr);
     if (procPtr == NULL) {
-	Tcl_AppendResult(interp,
-		"definition not available for this kind of method", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"definition not available for this kind of method", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "METHOD_TYPE", NULL);
 	return TCL_ERROR;
     }
@@ -1085,17 +1087,17 @@ InfoClassForwardCmd(
     }
     hPtr = Tcl_FindHashEntry(&clsPtr->classMethods, (char *) objv[2]);
     if (hPtr == NULL) {
-	Tcl_AppendResult(interp, "unknown method \"", TclGetString(objv[2]),
-		"\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"unknown method \"%s\"", TclGetString(objv[2])));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		TclGetString(objv[2]), NULL);
 	return TCL_ERROR;
     }
     prefixObj = TclOOGetFwdFromMethod(Tcl_GetHashValue(hPtr));
     if (prefixObj == NULL) {
-	Tcl_AppendResult(interp,
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		"prefix argument list not available for this kind of method",
-		NULL);
+		-1));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		TclGetString(objv[2]), NULL);
 	return TCL_ERROR;
@@ -1269,8 +1271,8 @@ InfoClassMethodTypeCmd(
     hPtr = Tcl_FindHashEntry(&clsPtr->classMethods, (char *) objv[2]);
     if (hPtr == NULL) {
     unknownMethod:
-	Tcl_AppendResult(interp, "unknown method \"", TclGetString(objv[2]),
-		"\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"unknown method \"%s\"", TclGetString(objv[2])));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		TclGetString(objv[2]), NULL);
 	return TCL_ERROR;
@@ -1494,7 +1496,8 @@ InfoObjectCallCmd(
 
     contextPtr = TclOOGetCallContext(oPtr, objv[2], PUBLIC_METHOD, NULL);
     if (contextPtr == NULL) {
-	Tcl_AppendResult(interp, "cannot construct any call chain", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"cannot construct any call chain", -1));
 	return TCL_ERROR;
     }
     Tcl_SetObjResult(interp,
@@ -1538,7 +1541,8 @@ InfoClassCallCmd(
 
     callPtr = TclOOGetStereotypeCallChain(clsPtr, objv[2], PUBLIC_METHOD);
     if (callPtr == NULL) {
-	Tcl_AppendResult(interp, "cannot construct any call chain", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"cannot construct any call chain", -1));
 	return TCL_ERROR;
     }
     Tcl_SetObjResult(interp, TclOORenderCallChain(interp, callPtr));
diff --git a/generic/tclOOMethod.c b/generic/tclOOMethod.c
index 877c3db..60eaa6e 100644
--- a/generic/tclOOMethod.c
+++ b/generic/tclOOMethod.c
@@ -1329,8 +1329,8 @@ TclOONewForwardInstanceMethod(
 	return NULL;
     }
     if (prefixLen < 1) {
-	Tcl_AppendResult(interp, "method forward prefix must be non-empty",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"method forward prefix must be non-empty", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "BAD_FORWARD", NULL);
 	return NULL;
     }
@@ -1371,8 +1371,8 @@ TclOONewForwardMethod(
 	return NULL;
     }
     if (prefixLen < 1) {
-	Tcl_AppendResult(interp, "method forward prefix must be non-empty",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"method forward prefix must be non-empty", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OO", "BAD_FORWARD", NULL);
 	return NULL;
     }
diff --git a/generic/tclOOStubLib.c b/generic/tclOOStubLib.c
index 3b6ce37..55f2378 100644
--- a/generic/tclOOStubLib.c
+++ b/generic/tclOOStubLib.c
@@ -53,8 +53,9 @@ TclOOInitializeStubs(
 
     if (clientData == NULL) {
 	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "Error loading ", packageName, " package; ",
-		"package not present or incomplete", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"error loading %s package; package not present or incomplete",
+		packageName));
 	return NULL;
     } else {
 	const TclOOStubs * const stubsPtr = clientData;
@@ -76,9 +77,9 @@ TclOOInitializeStubs(
 
     error:
 	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "Error loading ", packageName, " package",
-		" (requested version '", version, "', loaded version '",
-		actualVersion, "'): ", errMsg, NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf("Error loading %s package"
+		" (requested version '%s', loaded version '%s'): %s",
+		packageName, version, actualVersion, errMsg));
 	return NULL;
     }
 }
diff --git a/generic/tclObj.c b/generic/tclObj.c
index 099b67d..74cb29e 100644
--- a/generic/tclObj.c
+++ b/generic/tclObj.c
@@ -4462,11 +4462,8 @@ Tcl_RepresentationCmd(
     int objc,
     Tcl_Obj *const objv[])
 {
-    char refcountBuffer[TCL_INTEGER_SPACE+1];
-    char objPtrBuffer[TCL_INTEGER_SPACE+3];
-    char internalRepBuffer[2*(TCL_INTEGER_SPACE+2)+2];
-#define TCLOBJ_TRUNCATE_STRINGREP 16
-    char stringRepBuffer[TCLOBJ_TRUNCATE_STRINGREP+1];
+    char ptrBuffer[2*TCL_INTEGER_SPACE+6];
+    Tcl_Obj *descObj;
 
     if (objc != 2) {
 	Tcl_WrongNumArgs(interp, 1, objv, "value");
@@ -4479,27 +4476,30 @@ Tcl_RepresentationCmd(
      * "1872361827361287"
      */
 
-    sprintf(refcountBuffer, "%d", objv[1]->refCount);
-    sprintf(objPtrBuffer, "%p", (void *)objv[1]);
-    Tcl_AppendResult(interp, "value is a ", objv[1]->typePtr ?
-	    objv[1]->typePtr->name : "pure string", " with a refcount of ",
-	    refcountBuffer, ", object pointer at ", objPtrBuffer, NULL);
+    sprintf(ptrBuffer, "%p", (void *) objv[1]);
+    descObj = Tcl_ObjPrintf("value is a %s with a refcount of %d,"
+            " object pointer at %s",
+            objv[1]->typePtr ? objv[1]->typePtr->name : "pure string",
+	    objv[1]->refCount, ptrBuffer);
+
     if (objv[1]->typePtr) {
-	sprintf(internalRepBuffer, "%p:%p",
-		(void *)objv[1]->internalRep.twoPtrValue.ptr1,
-		(void *)objv[1]->internalRep.twoPtrValue.ptr2);
-	Tcl_AppendResult(interp, ", internal representation ",
-		internalRepBuffer, NULL);
+	sprintf(ptrBuffer, "%p:%p",
+		(void *) objv[1]->internalRep.twoPtrValue.ptr1,
+		(void *) objv[1]->internalRep.twoPtrValue.ptr2);
+	Tcl_AppendPrintfToObj(descObj, ", internal representation %s",
+		ptrBuffer);
     }
+
     if (objv[1]->bytes) {
-	strncpy(stringRepBuffer, objv[1]->bytes, TCLOBJ_TRUNCATE_STRINGREP);
-	stringRepBuffer[TCLOBJ_TRUNCATE_STRINGREP] = 0;
-	Tcl_AppendResult(interp, ", string representation \"",
-		stringRepBuffer, objv[1]->length > TCLOBJ_TRUNCATE_STRINGREP ?
-		"\"..." : "\".", NULL);
+        Tcl_AppendToObj(descObj, ", string representation \"", -1);
+	Tcl_AppendLimitedToObj(descObj, objv[1]->bytes, objv[1]->length,
+                16, "...");
+	Tcl_AppendToObj(descObj, "\"", -1);
     } else {
-	Tcl_AppendResult(interp, ", no string representation.", NULL);
+	Tcl_AppendToObj(descObj, ", no string representation", -1);
     }
+
+    Tcl_SetObjResult(interp, descObj);
     return TCL_OK;
 }
 
diff --git a/generic/tclParse.c b/generic/tclParse.c
index f0050c6..309e232 100644
--- a/generic/tclParse.c
+++ b/generic/tclParse.c
@@ -258,7 +258,8 @@ Tcl_ParseCommand(
 
     if ((start == NULL) && (numBytes != 0)) {
 	if (interp != NULL) {
-	    Tcl_SetResult(interp, "can't parse a NULL pointer", TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "can't parse a NULL pointer", -1));
 	}
 	return TCL_ERROR;
     }
@@ -568,14 +569,14 @@ Tcl_ParseCommand(
 	}
 	if (src[-1] == '"') {
 	    if (interp != NULL) {
-		Tcl_SetResult(interp, "extra characters after close-quote",
-			TCL_STATIC);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"extra characters after close-quote", -1));
 	    }
 	    parsePtr->errorType = TCL_PARSE_QUOTE_EXTRA;
 	} else {
 	    if (interp != NULL) {
-		Tcl_SetResult(interp, "extra characters after close-brace",
-			TCL_STATIC);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"extra characters after close-brace", -1));
 	    }
 	    parsePtr->errorType = TCL_PARSE_BRACE_EXTRA;
 	}
@@ -1175,8 +1176,8 @@ ParseTokens(
 		}
 		if (numBytes == 0) {
 		    if (parsePtr->interp != NULL) {
-			Tcl_SetResult(parsePtr->interp,
-				"missing close-bracket", TCL_STATIC);
+			Tcl_SetObjResult(parsePtr->interp, Tcl_NewStringObj(
+				"missing close-bracket", -1));
 		    }
 		    parsePtr->errorType = TCL_PARSE_MISSING_BRACKET;
 		    parsePtr->term = tokenPtr->start;
@@ -1411,8 +1412,8 @@ Tcl_ParseVarName(
 	}
 	if (numBytes == 0) {
 	    if (parsePtr->interp != NULL) {
-		Tcl_SetResult(parsePtr->interp,
-			"missing close-brace for variable name", TCL_STATIC);
+		Tcl_SetObjResult(parsePtr->interp, Tcl_NewStringObj(
+			"missing close-brace for variable name", -1));
 	    }
 	    parsePtr->errorType = TCL_PARSE_MISSING_VAR_BRACE;
 	    parsePtr->term = tokenPtr->start-1;
@@ -1479,8 +1480,8 @@ Tcl_ParseVarName(
 	    }
 	    if ((parsePtr->term == src+numBytes) || (*parsePtr->term != ')')){
 		if (parsePtr->interp != NULL) {
-		    Tcl_SetResult(parsePtr->interp, "missing )",
-			    TCL_STATIC);
+		    Tcl_SetObjResult(parsePtr->interp, Tcl_NewStringObj(
+			    "missing )", -1));
 		}
 		parsePtr->errorType = TCL_PARSE_MISSING_PAREN;
 		parsePtr->term = src;
@@ -1755,7 +1756,8 @@ Tcl_ParseBraces(
 	goto error;
     }
 
-    Tcl_SetResult(parsePtr->interp, "missing close-brace", TCL_STATIC);
+    Tcl_SetObjResult(parsePtr->interp, Tcl_NewStringObj(
+	    "missing close-brace", -1));
 
     /*
      * Guess if the problem is due to comments by searching the source string
@@ -1777,8 +1779,8 @@ Tcl_ParseBraces(
 		break;
 	    case '#' :
 		if (openBrace && TclIsSpaceProc(src[-1])) {
-		    Tcl_AppendResult(parsePtr->interp,
-			    ": possible unbalanced brace in comment", NULL);
+		    Tcl_AppendToObj(Tcl_GetObjResult(parsePtr->interp),
+			    ": possible unbalanced brace in comment", -1);
 		    goto error;
 		}
 		break;
@@ -1857,7 +1859,8 @@ Tcl_ParseQuotedString(
     }
     if (*parsePtr->term != '"') {
 	if (parsePtr->interp != NULL) {
-	    Tcl_SetResult(parsePtr->interp, "missing \"", TCL_STATIC);
+	    Tcl_SetObjResult(parsePtr->interp, Tcl_NewStringObj(
+		    "missing \"", -1));
 	}
 	parsePtr->errorType = TCL_PARSE_MISSING_QUOTE;
 	parsePtr->term = start;
diff --git a/generic/tclPathObj.c b/generic/tclPathObj.c
index 8bae4fb..db07c0e 100644
--- a/generic/tclPathObj.c
+++ b/generic/tclPathObj.c
@@ -1492,9 +1492,8 @@ MakePathFromNormalized(
 	if (pathPtr->bytes == NULL) {
 	    if (pathPtr->typePtr->updateStringProc == NULL) {
 		if (interp != NULL) {
-		    Tcl_ResetResult(interp);
-		    Tcl_AppendResult(interp, "can't find object"
-			    "string representation", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "can't find object string representation", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "VALUE", "PATH", "WTF",
 			    NULL);
 		}
@@ -2368,9 +2367,9 @@ SetFsPathFromAny(
 	    dir = TclGetEnv("HOME", &dirString);
 	    if (dir == NULL) {
 		if (interp) {
-		    Tcl_ResetResult(interp);
-		    Tcl_AppendResult(interp, "couldn't find HOME environment "
-			    "variable to expand path", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "couldn't find HOME environment variable to"
+			    " expand path", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "VALUE", "PATH",
 			    "HOMELESS", NULL);
 		}
@@ -2387,9 +2386,8 @@ SetFsPathFromAny(
 	    Tcl_DStringInit(&temp);
 	    if (TclpGetUserHome(name+1, &temp) == NULL) {
 		if (interp != NULL) {
-		    Tcl_ResetResult(interp);
-		    Tcl_AppendResult(interp, "user \"", name+1,
-			    "\" doesn't exist", NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			    "user \"%s\" doesn't exist", name+1));
 		    Tcl_SetErrorCode(interp, "TCL", "VALUE", "PATH", "NOUSER",
 			    NULL);
 		}
diff --git a/generic/tclPipe.c b/generic/tclPipe.c
index d0b136d..83fb818 100644
--- a/generic/tclPipe.c
+++ b/generic/tclPipe.c
@@ -106,9 +106,10 @@ FileForRedirect(
 	    if (msg) {
 		Tcl_SetObjResult(interp, msg);
 	    } else {
-		Tcl_AppendResult(interp, "channel \"",
-			Tcl_GetChannelName(chan), "\" wasn't opened for ",
-			((writing) ? "writing" : "reading"), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"channel \"%s\" wasn't opened for %s",
+			Tcl_GetChannelName(chan),
+			((writing) ? "writing" : "reading")));
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC",
 			"BADCHAN", NULL);
 	    }
@@ -141,9 +142,10 @@ FileForRedirect(
 	file = TclpOpenFile(name, flags);
 	Tcl_DStringFree(&nameString);
 	if (file == NULL) {
-	    Tcl_AppendResult(interp, "couldn't ",
-		    ((writing) ? "write" : "read"), " file \"", spec, "\": ",
-		    Tcl_PosixError(interp), NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "couldn't %s file \"%s\": %s",
+		    (writing ? "write" : "read"), spec,
+		    Tcl_PosixError(interp)));
 	    return NULL;
 	}
 	*closePtr = 1;
@@ -151,8 +153,8 @@ FileForRedirect(
     return file;
 
   badLastArg:
-    Tcl_AppendResult(interp, "can't specify \"", arg,
-	    "\" as last word in command", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "can't specify \"%s\" as last word in command", arg));
     Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", "SYNTAX", NULL);
     return NULL;
 }
@@ -304,8 +306,8 @@ TclCleanupChildren(
 		    msg =
 			"child process lost (is SIGCHLD ignored or trapped?)";
 		}
-		Tcl_AppendResult(interp, "error waiting for process to exit: ",
-			msg, NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"error waiting for process to exit: %s", msg));
 	    }
 	    continue;
 	}
@@ -335,16 +337,17 @@ TclCleanupChildren(
 		    p = Tcl_SignalMsg(WTERMSIG(waitStatus));
 		    Tcl_SetErrorCode(interp, "CHILDKILLED", msg1,
 			    Tcl_SignalId(WTERMSIG(waitStatus)), p, NULL);
-		    Tcl_AppendResult(interp, "child killed: ", p, "\n", NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			    "child killed: %s\n", p));
 		} else if (WIFSTOPPED(waitStatus)) {
 		    p = Tcl_SignalMsg(WSTOPSIG(waitStatus));
 		    Tcl_SetErrorCode(interp, "CHILDSUSP", msg1,
 			    Tcl_SignalId(WSTOPSIG(waitStatus)), p, NULL);
-		    Tcl_AppendResult(interp, "child suspended: ", p, "\n",
-			    NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			    "child suspended: %s\n", p));
 		} else {
-		    Tcl_AppendResult(interp,
-			    "child wait status didn't make sense\n", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "child wait status didn't make sense\n", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC",
 			    "ODDWAITRESULT", msg1, NULL);
 		}
@@ -374,8 +377,9 @@ TclCleanupChildren(
 		result = TCL_ERROR;
 		Tcl_DecrRefCount(objPtr);
 		Tcl_ResetResult(interp);
-		Tcl_AppendResult(interp, "error reading stderr output file: ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"error reading stderr output file: %s",
+			Tcl_PosixError(interp)));
 	    } else if (count > 0) {
 		anyErrorInfo = 1;
 		Tcl_SetObjResult(interp, objPtr);
@@ -393,7 +397,8 @@ TclCleanupChildren(
      */
 
     if ((abnormalExit != 0) && (anyErrorInfo == 0) && (interp != NULL)) {
-	Tcl_AppendResult(interp, "child process exited abnormally", NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"child process exited abnormally", -1));
     }
     return result;
 }
@@ -542,8 +547,8 @@ TclCreatePipeline(
 	    }
 	    if (*p == '\0') {
 		if ((i == (lastBar + 1)) || (i == (argc - 1))) {
-		    Tcl_SetResult(interp, "illegal use of | or |& in command",
-			    TCL_STATIC);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "illegal use of | or |& in command", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC",
 			    "PIPESYNTAX", NULL);
 		    goto error;
@@ -570,8 +575,9 @@ TclCreatePipeline(
 		if (*inputLiteral == '\0') {
 		    inputLiteral = ((i + 1) == argc) ? NULL : argv[i + 1];
 		    if (inputLiteral == NULL) {
-			Tcl_AppendResult(interp, "can't specify \"", argv[i],
-				"\" as last word in command", NULL);
+			Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+				"can't specify \"%s\" as last word in command",
+				argv[i]));
 			Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC",
 				"PIPESYNTAX", NULL);
 			goto error;
@@ -680,8 +686,9 @@ TclCreatePipeline(
 		 */
 
 		if (i != argc-1) {
-		    Tcl_AppendResult(interp, "must specify \"", argv[i],
-			    "\" as last word in command", NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			    "must specify \"%s\" as last word in command",
+			    argv[i]));
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC",
 			    "PIPESYNTAX", NULL);
 		    goto error;
@@ -722,8 +729,8 @@ TclCreatePipeline(
 	 * We had a bar followed only by redirections.
 	 */
 
-	Tcl_SetResult(interp, "illegal use of | or |& in command",
-		TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"illegal use of | or |& in command", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", "PIPESYNTAX",
 		NULL);
 	goto error;
@@ -739,9 +746,9 @@ TclCreatePipeline(
 
 	    inputFile = TclpCreateTempFile(inputLiteral);
 	    if (inputFile == NULL) {
-		Tcl_AppendResult(interp,
-			"couldn't create input file for command: ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"couldn't create input file for command: %s",
+			Tcl_PosixError(interp)));
 		goto error;
 	    }
 	    inputClose = 1;
@@ -752,9 +759,9 @@ TclCreatePipeline(
 	     */
 
 	    if (TclpCreatePipe(&inputFile, inPipePtr) == 0) {
-		Tcl_AppendResult(interp,
-			"couldn't create input pipe for command: ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"couldn't create input pipe for command: %s",
+			Tcl_PosixError(interp)));
 		goto error;
 	    }
 	    inputClose = 1;
@@ -781,9 +788,9 @@ TclCreatePipeline(
 	     */
 
 	    if (TclpCreatePipe(outPipePtr, &outputFile) == 0) {
-		Tcl_AppendResult(interp,
-			"couldn't create output pipe for command: ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"couldn't create output pipe for command: %s",
+			Tcl_PosixError(interp)));
 		goto error;
 	    }
 	    outputClose = 1;
@@ -821,9 +828,9 @@ TclCreatePipeline(
 
 	    errorFile = TclpCreateTempFile(NULL);
 	    if (errorFile == NULL) {
-		Tcl_AppendResult(interp,
-			"couldn't create error file for command: ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"couldn't create error file for command: %s",
+			Tcl_PosixError(interp)));
 		goto error;
 	    }
 	    *errFilePtr = errorFile;
@@ -894,8 +901,8 @@ TclCreatePipeline(
 	} else {
 	    argv[lastArg] = NULL;
 	    if (TclpCreatePipe(&pipeIn, &curOutFile) == 0) {
-		Tcl_AppendResult(interp, "couldn't create pipe: ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"couldn't create pipe: %s", Tcl_PosixError(interp)));
 		goto error;
 	    }
 	}
@@ -1074,15 +1081,17 @@ Tcl_OpenCommandChannel(
 
     if (flags & TCL_ENFORCE_MODE) {
 	if ((flags & TCL_STDOUT) && (outPipe == NULL)) {
-	    Tcl_AppendResult(interp, "can't read output from command:"
-		    " standard output was redirected", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "can't read output from command:"
+		    " standard output was redirected", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC",
 		    "BADREDIRECT", NULL);
 	    goto error;
 	}
 	if ((flags & TCL_STDIN) && (inPipe == NULL)) {
-	    Tcl_AppendResult(interp, "can't write input to command:"
-		    " standard input was redirected", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "can't write input to command:"
+		    " standard input was redirected", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC",
 		    "BADREDIRECT", NULL);
 	    goto error;
@@ -1093,8 +1102,8 @@ Tcl_OpenCommandChannel(
 	    numPids, pidPtr);
 
     if (channel == NULL) {
-	Tcl_AppendResult(interp, "pipe for command could not be created",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"pipe for command could not be created", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "EXEC", "NOPIPE", NULL);
 	goto error;
     }
diff --git a/generic/tclPkg.c b/generic/tclPkg.c
index 382ffe3..9b6e942 100644
--- a/generic/tclPkg.c
+++ b/generic/tclPkg.c
@@ -154,8 +154,9 @@ Tcl_PkgProvideEx(
 	}
 	return TCL_OK;
     }
-    Tcl_AppendResult(interp, "conflicting versions provided for package \"",
-	    name, "\": ", pkgPtr->version, ", then ", version, NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "conflicting versions provided for package \"%s\": %s, then %s",
+	    name, pkgPtr->version, version));
     Tcl_SetErrorCode(interp, "TCL", "PACKAGE", "VERSIONCONFLICT", NULL);
     return TCL_ERROR;
 }
@@ -284,9 +285,9 @@ Tcl_PkgRequireEx(
 	 */
 
 	tclEmptyStringRep = &tclEmptyString;
-	Tcl_AppendResult(interp, "Cannot load package \"", name,
-		"\" in standalone executable: This package is not "
-		"compiled with stub support", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"Cannot load package \"%s\" in standalone executable:"
+		" This package is not compiled with stub support", name));
 	Tcl_SetErrorCode(interp, "TCL", "PACKAGE", "UNSTUBBED", NULL);
 	return NULL;
     }
@@ -374,9 +375,10 @@ PkgRequireCore(
 	 */
 
 	if (pkgPtr->clientData != NULL) {
-	    Tcl_AppendResult(interp, "circular package dependency: "
-		    "attempt to provide ", name, " ",
-		    (char *) pkgPtr->clientData, " requires ", name, NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "circular package dependency:"
+		    " attempt to provide %s %s requires %s", 
+		    name, (char *) pkgPtr->clientData, name));
 	    AddRequirementsToResult(interp, reqc, reqv);
 	    Tcl_SetErrorCode(interp, "TCL", "PACKAGE", "CIRCULARITY", NULL);
 	    return NULL;
@@ -494,10 +496,10 @@ PkgRequireCore(
 		Tcl_ResetResult(interp);
 		if (pkgPtr->version == NULL) {
 		    code = TCL_ERROR;
-		    Tcl_AppendResult(interp, "attempt to provide package ",
-			    name, " ", versionToProvide,
-			    " failed: no version of package ", name,
-			    " provided", NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			    "attempt to provide package %s %s failed:"
+			    " no version of package %s provided",
+			    name, versionToProvide, name));
 		    Tcl_SetErrorCode(interp, "TCL", "PACKAGE", "UNPROVIDED",
 			    NULL);
 		} else {
@@ -517,11 +519,11 @@ PkgRequireCore(
 			ckfree(vi);
 			if (res != 0) {
 			    code = TCL_ERROR;
-			    Tcl_AppendResult(interp,
-				    "attempt to provide package ", name, " ",
-				    versionToProvide, " failed: package ",
-				    name, " ", pkgPtr->version,
-				    " provided instead", NULL);
+			    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+				    "attempt to provide package %s %s failed:"
+				    " package %s %s provided instead",
+				    name, versionToProvide,
+				    name, pkgPtr->version));
 			    Tcl_SetErrorCode(interp, "TCL", "PACKAGE",
 				    "WRONGPROVIDE", NULL);
 			}
@@ -530,10 +532,10 @@ PkgRequireCore(
 	    } else if (code != TCL_ERROR) {
 		Tcl_Obj *codePtr = Tcl_NewIntObj(code);
 
-		Tcl_ResetResult(interp);
-		Tcl_AppendResult(interp, "attempt to provide package ", name,
-			" ", versionToProvide, " failed: bad return code: ",
-			TclGetString(codePtr), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"attempt to provide package %s %s failed:"
+			" bad return code: %s",
+			name, versionToProvide, TclGetString(codePtr)));
 		Tcl_SetErrorCode(interp, "TCL", "PACKAGE", "BADRESULT", NULL);
 		TclDecrRefCount(codePtr);
 		code = TCL_ERROR;
@@ -591,13 +593,9 @@ PkgRequireCore(
 	    Tcl_DStringFree(&command);
 
 	    if ((code != TCL_OK) && (code != TCL_ERROR)) {
-		Tcl_Obj *codePtr = Tcl_NewIntObj(code);
-
-		Tcl_ResetResult(interp);
-		Tcl_AppendResult(interp, "bad return code: ",
-			TclGetString(codePtr), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"bad return code: %d", code));
 		Tcl_SetErrorCode(interp, "TCL", "PACKAGE", "BADRESULT", NULL);
-		Tcl_DecrRefCount(codePtr);
 		code = TCL_ERROR;
 	    }
 	    if (code == TCL_ERROR) {
@@ -610,7 +608,8 @@ PkgRequireCore(
     }
 
     if (pkgPtr->version == NULL) {
-	Tcl_AppendResult(interp, "can't find package ", name, NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"can't find package %s", name));
 	Tcl_SetErrorCode(interp, "TCL", "PACKAGE", "UNFOUND", NULL);
 	AddRequirementsToResult(interp, reqc, reqv);
 	return NULL;
@@ -628,8 +627,9 @@ PkgRequireCore(
 	ckfree(pkgVersionI);
 
 	if (!satisfies) {
-	    Tcl_AppendResult(interp, "version conflict for package \"", name,
-		    "\": have ", pkgPtr->version, ", need", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "version conflict for package \"%s\": have %s, need",
+		    name, pkgPtr->version));
 	    Tcl_SetErrorCode(interp, "TCL", "PACKAGE", "VERSIONCONFLICT",
 		    NULL);
 	    AddRequirementsToResult(interp, reqc, reqv);
@@ -721,10 +721,11 @@ Tcl_PkgPresentEx(
     }
 
     if (version != NULL) {
-	Tcl_AppendResult(interp, "package ", name, " ", version,
-		" is not present", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"package %s %s is not present", name, version));
     } else {
-	Tcl_AppendResult(interp, "package ", name, " is not present", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"package %s is not present", name));
     }
     Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "PACKAGE", name, NULL);
     return NULL;
@@ -850,7 +851,8 @@ Tcl_PackageObjCmd(
 	    if (res == 0){
 		if (objc == 4) {
 		    ckfree(argv3i);
-		    Tcl_SetResult(interp, availPtr->script, TCL_VOLATILE);
+		    Tcl_SetObjResult(interp,
+			    Tcl_NewStringObj(availPtr->script, -1));
 		    return TCL_OK;
 		}
 		Tcl_EventuallyFree(availPtr->script, TCL_DYNAMIC);
@@ -955,7 +957,8 @@ Tcl_PackageObjCmd(
 	    if (hPtr != NULL) {
 		pkgPtr = Tcl_GetHashValue(hPtr);
 		if (pkgPtr->version != NULL) {
-		    Tcl_SetResult(interp, pkgPtr->version, TCL_VOLATILE);
+		    Tcl_SetObjResult(interp,
+			    Tcl_NewStringObj(pkgPtr->version, -1));
 		}
 	    }
 	    return TCL_OK;
@@ -1017,7 +1020,8 @@ Tcl_PackageObjCmd(
 
 	if (objc == 2) {
 	    if (iPtr->packageUnknown != NULL) {
-		Tcl_SetResult(interp, iPtr->packageUnknown, TCL_VOLATILE);
+		Tcl_SetObjResult(interp,
+			Tcl_NewStringObj(iPtr->packageUnknown, -1));
 	    }
 	} else if (objc == 3) {
 	    if (iPtr->packageUnknown != NULL) {
@@ -1351,8 +1355,8 @@ CheckVersionAndConvert(
 
   error:
     ckfree(ibuf);
-    Tcl_AppendResult(interp, "expected version number but got \"", string,
-	    "\"", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "expected version number but got \"%s\"", string));
     Tcl_SetErrorCode(interp, "TCL", "VALUE", "VERSION", NULL);
     return TCL_ERROR;
 }
@@ -1614,8 +1618,8 @@ CheckRequirement(
 	 * More dashes found after the first. This is wrong.
 	 */
 
-	Tcl_AppendResult(interp, "expected versionMin-versionMax but got \"",
-		string, "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"expected versionMin-versionMax but got \"%s\"", string));
 	Tcl_SetErrorCode(interp, "TCL", "VALUE", "VERSIONRANGE", NULL);
 	return TCL_ERROR;
     }
@@ -1667,19 +1671,17 @@ AddRequirementsToResult(
     Tcl_Obj *const reqv[])	/* 0 means to use the latest version
 				 * available. */
 {
-    if (reqc > 0) {
-	int i;
+    Tcl_Obj *result = Tcl_GetObjResult(interp);
+    int i, length;
 
-	for (i = 0; i < reqc; i++) {
-	    int length;
-	    const char *v = Tcl_GetStringFromObj(reqv[i], &length);
+    for (i = 0; i < reqc; i++) {
+	const char *v = Tcl_GetStringFromObj(reqv[i], &length);
 
-	    if ((length & 0x1) && (v[length/2] == '-')
-		    && (strncmp(v, v+((length+1)/2), length/2) == 0)) {
-		Tcl_AppendResult(interp, " exactly ", v+((length+1)/2), NULL);
-	    } else {
-		Tcl_AppendResult(interp, " ", v, NULL);
-	    }
+	if ((length & 0x1) && (v[length/2] == '-')
+		&& (strncmp(v, v+((length+1)/2), length/2) == 0)) {
+	    Tcl_AppendPrintfToObj(result, " exactly %s", v+((length+1)/2));
+	} else {
+	    Tcl_AppendPrintfToObj(result, " %s", v);
 	}
     }
 }
@@ -1708,9 +1710,9 @@ AddRequirementsToDString(
     Tcl_Obj *const reqv[])	/* 0 means to use the latest version
 				 * available. */
 {
-    if (reqc > 0) {
-	int i;
+    int i;
 
+    if (reqc > 0) {
 	for (i = 0; i < reqc; i++) {
 	    TclDStringAppendLiteral(dsPtr, " ");
 	    TclDStringAppendObj(dsPtr, reqv[i]);
diff --git a/generic/tclProc.c b/generic/tclProc.c
index 537008c..933e7d2 100644
--- a/generic/tclProc.c
+++ b/generic/tclProc.c
@@ -152,22 +152,24 @@ Tcl_ProcObjCmd(
 	    &nsPtr, &altNsPtr, &cxtNsPtr, &procName);
 
     if (nsPtr == NULL) {
-	Tcl_AppendResult(interp, "can't create procedure \"", fullName,
-		"\": unknown namespace", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"can't create procedure \"%s\": unknown namespace",
+		fullName));
 	Tcl_SetErrorCode(interp, "TCL", "VALUE", "COMMAND", NULL);
 	return TCL_ERROR;
     }
     if (procName == NULL) {
-	Tcl_AppendResult(interp, "can't create procedure \"", fullName,
-		"\": bad procedure name", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"can't create procedure \"%s\": bad procedure name",
+		fullName));
 	Tcl_SetErrorCode(interp, "TCL", "VALUE", "COMMAND", NULL);
 	return TCL_ERROR;
     }
     if ((nsPtr != iPtr->globalNsPtr)
 	    && (procName != NULL) && (procName[0] == ':')) {
-	Tcl_AppendResult(interp, "can't create procedure \"", procName,
-		"\" in non-global namespace with name starting with \":\"",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"can't create procedure \"%s\" in non-global namespace with"
+		" name starting with \":\"", procName));
 	Tcl_SetErrorCode(interp, "TCL", "VALUE", "COMMAND", NULL);
 	return TCL_ERROR;
     }
@@ -518,16 +520,17 @@ TclCreateProc(
 	}
 	if (fieldCount > 2) {
 	    ckfree(fieldValues);
-	    Tcl_AppendResult(interp,
-		    "too many fields in argument specifier \"",
-		    argArray[i], "\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "too many fields in argument specifier \"%s\"",
+		    argArray[i]));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "PROC",
 		    "FORMALARGUMENTFORMAT", NULL);
 	    goto procError;
 	}
 	if ((fieldCount == 0) || (*fieldValues[0] == 0)) {
 	    ckfree(fieldValues);
-	    Tcl_AppendResult(interp, "argument with no name", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "argument with no name", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "PROC",
 		    "FORMALARGUMENTFORMAT", NULL);
 	    goto procError;
@@ -553,16 +556,18 @@ TclCreateProc(
 		} while (*q != '\0');
 		q--;
 		if (*q == ')') {	/* We have an array element. */
-		    Tcl_AppendResult(interp, "formal parameter \"",
-			    fieldValues[0], "\" is an array element", NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			    "formal parameter \"%s\" is an array element",
+			    fieldValues[0]));
 		    ckfree(fieldValues);
 		    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "PROC",
 			    "FORMALARGUMENTFORMAT", NULL);
 		    goto procError;
 		}
 	    } else if ((*p == ':') && (*(p+1) == ':')) {
-		Tcl_AppendResult(interp, "formal parameter \"",
-			fieldValues[0], "\" is not a simple name", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"formal parameter \"%s\" is not a simple name",
+			fieldValues[0]));
 		ckfree(fieldValues);
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "PROC",
 			"FORMALARGUMENTFORMAT", NULL);
@@ -767,8 +772,7 @@ TclGetFrame(
     return result;
 
   levelError:
-    Tcl_ResetResult(interp);
-    Tcl_AppendResult(interp, "bad level \"", name, "\"", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf("bad level \"%s\"", name));
     Tcl_SetErrorCode(interp, "TCL", "VALUE", "STACKLEVEL", NULL);
     return -1;
 }
@@ -900,8 +904,7 @@ TclObjGetFrame(
     return result;
 
   levelError:
-    Tcl_ResetResult(interp);
-    Tcl_AppendResult(interp, "bad level \"", name, "\"", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf("bad level \"%s\"", name));
     Tcl_SetErrorCode(interp, "TCL", "VALUE", "STACKLEVEL", NULL);
     return -1;
 }
@@ -1879,10 +1882,9 @@ InterpProcNR2(
 	 * transform to an error now.
 	 */
 
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "invoked \"",
-		((result == TCL_BREAK) ? "break" : "continue"),
-		"\" outside of a loop", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"invoked \"%s\" outside of a loop",
+		((result == TCL_BREAK) ? "break" : "continue")));
 	Tcl_SetErrorCode(interp, "TCL", "RESULT", "UNEXPECTED", NULL);
 	result = TCL_ERROR;
 
@@ -1999,8 +2001,8 @@ TclProcCompileProc(
 
 	if (codePtr->flags & TCL_BYTECODE_PRECOMPILED) {
 	    if ((Interp *) *codePtr->interpHandle != iPtr) {
-		Tcl_AppendResult(interp,
-			"a precompiled script jumped interps", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"a precompiled script jumped interps", -1));
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "PROC",
 			"CROSSINTERPBYTECODE", NULL);
 		return TCL_ERROR;
@@ -2932,8 +2934,8 @@ Tcl_DisassembleObjCmd(
 
 	procPtr = TclFindProc((Interp *) interp, TclGetString(objv[2]));
 	if (procPtr == NULL) {
-	    Tcl_AppendResult(interp, "\"", TclGetString(objv[2]),
-		    "\" isn't a procedure", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "\"%s\" isn't a procedure", TclGetString(objv[2])));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "PROC",
 		    TclGetString(objv[2]), NULL);
 	    return TCL_ERROR;
@@ -2982,8 +2984,8 @@ Tcl_DisassembleObjCmd(
 	    return TCL_ERROR;
 	}
 	if (oPtr->classPtr == NULL) {
-	    Tcl_AppendResult(interp, "\"", TclGetString(objv[2]),
-		    "\" is not a class", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "\"%s\" is not a class", TclGetString(objv[2])));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "CLASS",
 		    TclGetString(objv[2]), NULL);
 	    return TCL_ERROR;
@@ -3017,16 +3019,16 @@ Tcl_DisassembleObjCmd(
     methodBody:
 	if (hPtr == NULL) {
 	unknownMethod:
-	    Tcl_AppendResult(interp, "unknown method \"",
-		    TclGetString(objv[3]), "\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "unknown method \"%s\"", TclGetString(objv[3])));
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "METHOD",
 		    TclGetString(objv[3]), NULL);
 	    return TCL_ERROR;
 	}
 	procPtr = TclOOGetProcFromMethod(Tcl_GetHashValue(hPtr));
 	if (procPtr == NULL) {
-	    Tcl_AppendResult(interp,
-		    "body not available for this kind of method", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "body not available for this kind of method", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "DISASSEMBLE",
 		    "METHODTYPE", NULL);
 	    return TCL_ERROR;
@@ -3061,7 +3063,8 @@ Tcl_DisassembleObjCmd(
 
     if (((ByteCode *) codeObjPtr->internalRep.otherValuePtr)->flags
 	    & TCL_BYTECODE_PRECOMPILED) {
-	Tcl_AppendResult(interp,"may not disassemble prebuilt bytecode",NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"may not disassemble prebuilt bytecode", -1));
 	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "DISASSEMBLE",
 		"BYTECODE", NULL);
 	return TCL_ERROR;
diff --git a/generic/tclRegexp.c b/generic/tclRegexp.c
index 53d7153..6c1dc08 100644
--- a/generic/tclRegexp.c
+++ b/generic/tclRegexp.c
@@ -714,14 +714,14 @@ TclRegError(
     int status)			/* Status code to report. */
 {
     char buf[100];		/* ample in practice */
-    char cbuf[100];		/* lots in practice */
+    char cbuf[TCL_INTEGER_SPACE];
     size_t n;
     const char *p;
 
     Tcl_ResetResult(interp);
     n = TclReError(status, NULL, buf, sizeof(buf));
     p = (n > sizeof(buf)) ? "..." : "";
-    Tcl_AppendResult(interp, msg, buf, p, NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf("%s%s%s", msg, buf, p));
 
     sprintf(cbuf, "%d", status);
     (void) TclReError(REG_ITOA, NULL, cbuf, sizeof(cbuf));
diff --git a/generic/tclResult.c b/generic/tclResult.c
index 4443cc1..17aac74 100644
--- a/generic/tclResult.c
+++ b/generic/tclResult.c
@@ -1390,10 +1390,9 @@ TclMergeReturnOptions(
 		 * Value is not a legal dictionary.
 		 */
 
-		Tcl_ResetResult(interp);
-		Tcl_AppendResult(interp, "bad ", compare,
-			" value: expected dictionary but got \"",
-			TclGetString(objv[1]), "\"", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                        "bad %s value: expected dictionary but got \"%s\"",
+                        compare, TclGetString(objv[1])));
 		Tcl_SetErrorCode(interp, "TCL", "RESULT", "ILLEGAL_OPTIONS",
 			NULL);
 		goto error;
@@ -1440,10 +1439,9 @@ TclMergeReturnOptions(
 	     * Value is not a legal level.
 	     */
 
-	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "bad -level value: "
-		    "expected non-negative integer but got \"",
-		    TclGetString(valuePtr), "\"", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "bad -level value: expected non-negative integer but got"
+                    " \"%s\"", TclGetString(valuePtr)));
 	    Tcl_SetErrorCode(interp, "TCL", "RESULT", "ILLEGAL_LEVEL", NULL);
 	    goto error;
 	}
@@ -1462,10 +1460,10 @@ TclMergeReturnOptions(
 	    /*
 	     * Value is not a list, which is illegal for -errorcode.
 	     */
-	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "bad -errorcode value: "
-			     "expected a list but got \"",
-			     TclGetString(valuePtr), "\"", NULL);
+
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "bad -errorcode value: expected a list but got \"%s\"",
+                    TclGetString(valuePtr)));
 	    Tcl_SetErrorCode(interp, "TCL", "RESULT", "ILLEGAL_ERRORCODE",
 		    NULL);
 	    goto error;
@@ -1484,10 +1482,10 @@ TclMergeReturnOptions(
 	    /*
 	     * Value is not a list, which is illegal for -errorstack.
 	     */
-	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "bad -errorstack value: "
-		    "expected a list but got \"", TclGetString(valuePtr),
-                    "\"", NULL);
+
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "bad -errorstack value: expected a list but got \"%s\"",
+                    TclGetString(valuePtr)));
 	    Tcl_SetErrorCode(interp, "TCL", "RESULT", "NONLIST_ERRORSTACK",
                     NULL);
 	    goto error;
@@ -1496,10 +1494,10 @@ TclMergeReturnOptions(
             /*
              * Errorstack must always be an even-sized list
              */
-            Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp,
-                    "forbidden odd-sized list for -errorstack: \"",
-		    TclGetString(valuePtr), "\"", NULL);
+
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "forbidden odd-sized list for -errorstack: \"%s\"",
+		    TclGetString(valuePtr)));
 	    Tcl_SetErrorCode(interp, "TCL", "RESULT",
                     "ODDSIZEDLIST_ERRORSTACK", NULL);
 	    goto error;
@@ -1650,9 +1648,8 @@ Tcl_SetReturnOptions(
     Tcl_IncrRefCount(options);
     if (TCL_ERROR == TclListObjGetElements(interp, options, &objc, &objv)
 	    || (objc % 2)) {
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "expected dict but got \"",
-		TclGetString(options), "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "expected dict but got \"%s\"", TclGetString(options)));
 	Tcl_SetErrorCode(interp, "TCL", "RESULT", "ILLEGAL_OPTIONS", NULL);
 	code = TCL_ERROR;
     } else if (TCL_ERROR == TclMergeReturnOptions(interp, objc, objv,
diff --git a/generic/tclScan.c b/generic/tclScan.c
index d21bfaf..ef7eedf 100644
--- a/generic/tclScan.c
+++ b/generic/tclScan.c
@@ -261,6 +261,10 @@ ValidateFormat(
     int objIndex, xpgSize, nspace = numVars;
     int *nassign = TclStackAlloc(interp, nspace * sizeof(int));
     char buf[TCL_UTF_MAX+1];
+    Tcl_Obj *errorMsg;		/* Place to build an error messages. Note that
+				 * these are messy operations because we do
+				 * not want to use the formatting engine;
+				 * we're inside there! */
 
     /*
      * Initialize an array that records the number of times a variable is
@@ -328,9 +332,9 @@ ValidateFormat(
 	gotSequential = 1;
 	if (gotXpg) {
 	mixedXPG:
-	    Tcl_SetResult(interp,
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "cannot mix \"%\" and \"%n$\" conversion specifiers",
-		    TCL_STATIC);
+		    -1));
 	    Tcl_SetErrorCode(interp, "TCL", "FORMAT", "MIXEDSPECTYPES", NULL);
 	    goto error;
 	}
@@ -375,9 +379,9 @@ ValidateFormat(
 	switch (ch) {
 	case 'c':
 	    if (flags & SCAN_WIDTH) {
-		Tcl_SetResult(interp,
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			"field width may not be specified in %c conversion",
-			TCL_STATIC);
+			-1));
 		Tcl_SetErrorCode(interp, "TCL", "FORMAT", "BADWIDTH", NULL);
 		goto error;
 	    }
@@ -389,9 +393,11 @@ ValidateFormat(
 	    if (flags & (SCAN_LONGER|SCAN_BIG)) {
 	    invalidFieldSize:
 		buf[Tcl_UniCharToUtf(ch, buf)] = '\0';
-		Tcl_AppendResult(interp,
-			"field size modifier may not be specified in %", buf,
-			" conversion", NULL);
+		errorMsg = Tcl_NewStringObj(
+			"field size modifier may not be specified in %", -1);
+		Tcl_AppendToObj(errorMsg, buf, -1);
+		Tcl_AppendToObj(errorMsg, " conversion", -1);
+		Tcl_SetObjResult(interp, errorMsg);
 		Tcl_SetErrorCode(interp, "TCL", "FORMAT", "BADSIZE", NULL);
 		goto error;
 	    }
@@ -409,8 +415,8 @@ ValidateFormat(
 	    break;
 	case 'u':
 	    if (flags & SCAN_BIG) {
-		Tcl_SetResult(interp,
-			"unsigned bignum scans are invalid", TCL_STATIC);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"unsigned bignum scans are invalid", -1));
 		Tcl_SetErrorCode(interp, "TCL", "FORMAT", "BADUNSIGNED",NULL);
 		goto error;
 	    }
@@ -446,15 +452,18 @@ ValidateFormat(
 	    }
 	    break;
 	badSet:
-	    Tcl_SetResult(interp, "unmatched [ in format string",
-		    TCL_STATIC);
-		Tcl_SetErrorCode(interp, "TCL", "FORMAT", "BRACKET", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "unmatched [ in format string", -1));
+	    Tcl_SetErrorCode(interp, "TCL", "FORMAT", "BRACKET", NULL);
 	    goto error;
 	default:
 	    buf[Tcl_UniCharToUtf(ch, buf)] = '\0';
-	    Tcl_AppendResult(interp, "bad scan conversion character \"", buf,
-		    "\"", NULL);
-		Tcl_SetErrorCode(interp, "TCL", "FORMAT", "BADTYPE", NULL);
+	    errorMsg = Tcl_NewStringObj(
+		    "bad scan conversion character \"", -1);
+	    Tcl_AppendToObj(errorMsg, buf, -1);
+	    Tcl_AppendToObj(errorMsg, "\"", -1);
+	    Tcl_SetObjResult(interp, errorMsg);
+	    Tcl_SetErrorCode(interp, "TCL", "FORMAT", "BADTYPE", NULL);
 	    goto error;
 	}
 	if (!(flags & SCAN_SUPPRESS)) {
@@ -498,9 +507,9 @@ ValidateFormat(
     }
     for (i = 0; i < numVars; i++) {
 	if (nassign[i] > 1) {
-	    Tcl_SetResult(interp,
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "variable is assigned by multiple \"%n$\" conversion specifiers",
-		    TCL_STATIC);
+		    -1));
 	    Tcl_SetErrorCode(interp, "TCL", "FORMAT", "POLYASSIGNED", NULL);
 	    goto error;
 	} else if (!xpgSize && (nassign[i] == 0)) {
@@ -509,9 +518,9 @@ ValidateFormat(
 	     * and/or numVars != 0), then too many vars were given
 	     */
 
-	    Tcl_SetResult(interp,
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "variable is not assigned by any conversion specifiers",
-		    TCL_STATIC);
+		    -1));
 	    Tcl_SetErrorCode(interp, "TCL", "FORMAT", "UNASSIGNED", NULL);
 	    goto error;
 	}
@@ -522,13 +531,13 @@ ValidateFormat(
 
   badIndex:
     if (gotXpg) {
-	Tcl_SetResult(interp, "\"%n$\" argument index out of range",
-		TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"\"%n$\" argument index out of range", -1));
 	Tcl_SetErrorCode(interp, "TCL", "FORMAT", "INDEXRANGE", NULL);
     } else {
-	Tcl_SetResult(interp,
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		"different numbers of variable names and field specifiers",
-		TCL_STATIC);
+		-1));
 	Tcl_SetErrorCode(interp, "TCL", "FORMAT", "FIELDVARMISMATCH", NULL);
     }
 
diff --git a/generic/tclTest.c b/generic/tclTest.c
index b4192b2..aa5a46d 100644
--- a/generic/tclTest.c
+++ b/generic/tclTest.c
@@ -16,7 +16,7 @@
  */
 
 #ifndef _WIN64
-/* See [Bug 2935503]: file mtime sets wrong time */
+/* See [Bug 3354324]: file mtime sets wrong time */
 #   define _USE_32BIT_TIME_T
 #endif
 
diff --git a/generic/tclTimer.c b/generic/tclTimer.c
index 36adaad..6b17825 100644
--- a/generic/tclTimer.c
+++ b/generic/tclTimer.c
@@ -829,8 +829,9 @@ Tcl_AfterObjCmd(
 	if (Tcl_GetWideIntFromObj(NULL, objv[1], &ms) != TCL_OK) {
             const char *arg = Tcl_GetString(objv[1]);
 
-	    Tcl_AppendResult(interp, "bad argument \"", arg,
-		    "\": must be cancel, idle, info, or an integer", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "bad argument \"%s\": must be"
+                    " cancel, idle, info, or an integer", arg));
             Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "INDEX", "argument",
                     arg, NULL);
 	    return TCL_ERROR;
@@ -968,8 +969,8 @@ Tcl_AfterObjCmd(
 	if (afterPtr == NULL) {
             const char *eventStr = TclGetString(objv[2]);
 
-	    Tcl_AppendResult(interp, "event \"", eventStr, "\" doesn't exist",
-                    NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                    "event \"%s\" doesn't exist", eventStr));
             Tcl_SetErrorCode(interp, "TCL","LOOKUP","EVENT", eventStr, NULL);
 	    return TCL_ERROR;
 	} else {
diff --git a/generic/tclTomMathStubLib.c b/generic/tclTomMathStubLib.c
index e7e4aea..a3bc4b3 100644
--- a/generic/tclTomMathStubLib.c
+++ b/generic/tclTomMathStubLib.c
@@ -73,10 +73,10 @@ TclTomMathInitializeStubs(
 	tclTomMathStubsPtr = stubsPtr;
 	return actualVersion;
     }
-    Tcl_ResetResult(interp);
-    Tcl_AppendResult(interp, "error loading ", packageName,
-	    " (requested version ", version, ", actual version ",
-	    actualVersion, "): ", errMsg, NULL);
+
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "error loading %s (requested version %s, actual version %s): %s",
+	    packageName, version, actualVersion, errMsg));
     return NULL;
 }
 
diff --git a/generic/tclTrace.c b/generic/tclTrace.c
index 529c38a..519f201 100644
--- a/generic/tclTrace.c
+++ b/generic/tclTrace.c
@@ -366,8 +366,9 @@ Tcl_TraceObjCmd(
     return TCL_OK;
 
   badVarOps:
-    Tcl_AppendResult(interp, "bad operations \"", flagOps,
-	    "\": should be one or more of rwua", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "bad operations \"%s\": should be one or more of rwua",
+	    flagOps));
     Tcl_SetErrorCode(interp, "TCL", "OPERATION", "TRACE", "BADOPS", NULL);
     return TCL_ERROR;
 }
@@ -434,9 +435,9 @@ TraceExecutionObjCmd(
 	    return result;
 	}
 	if (listLen == 0) {
-	    Tcl_SetResult(interp, "bad operation list \"\": must be "
-		    "one or more of enter, leave, enterstep, or leavestep",
-		    TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "bad operation list \"\": must be one or more of"
+		    " enter, leave, enterstep, or leavestep", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "TRACE", "NOOPS",
 		    NULL);
 	    return TCL_ERROR;
@@ -677,8 +678,9 @@ TraceCommandObjCmd(
 	    return result;
 	}
 	if (listLen == 0) {
-	    Tcl_SetResult(interp, "bad operation list \"\": must be "
-		    "one or more of delete or rename", TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "bad operation list \"\": must be one or more of"
+		    " delete or rename", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "TRACE", "NOOPS",
 		    NULL);
 	    return TCL_ERROR;
@@ -875,8 +877,9 @@ TraceVariableObjCmd(
 	    return result;
 	}
 	if (listLen == 0) {
-	    Tcl_SetResult(interp, "bad operation list \"\": must be "
-		    "one or more of array, read, unset, or write", TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "bad operation list \"\": must be one or more of"
+		    " array, read, unset, or write", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "TRACE", "NOOPS",
 		    NULL);
 	    return TCL_ERROR;
@@ -2715,7 +2718,8 @@ TclCallVarTraces(
 	    if (disposeFlags & TCL_TRACE_RESULT_OBJECT) {
 		Tcl_SetObjResult((Tcl_Interp *)iPtr, (Tcl_Obj *) result);
 	    } else {
-		Tcl_SetResult((Tcl_Interp *)iPtr, result, TCL_STATIC);
+		Tcl_SetObjResult((Tcl_Interp *)iPtr,
+			Tcl_NewStringObj(result, -1));
 	    }
 	    Tcl_AddErrorInfo((Tcl_Interp *)iPtr, "");
 
diff --git a/generic/tclUtil.c b/generic/tclUtil.c
index 63c9fb2..6d42080 100644
--- a/generic/tclUtil.c
+++ b/generic/tclUtil.c
@@ -655,16 +655,16 @@ TclFindElement(
     if (p == limit) {
 	if (openBraces != 0) {
 	    if (interp != NULL) {
-		Tcl_SetResult(interp, "unmatched open brace in list",
-			TCL_STATIC);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"unmatched open brace in list", -1));
 		Tcl_SetErrorCode(interp, "TCL", "VALUE", "LIST", "BRACE",
 			NULL);
 	    }
 	    return TCL_ERROR;
 	} else if (inQuotes) {
 	    if (interp != NULL) {
-		Tcl_SetResult(interp, "unmatched open quote in list",
-			TCL_STATIC);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"unmatched open quote in list", -1));
 		Tcl_SetErrorCode(interp, "TCL", "VALUE", "LIST", "QUOTE",
 			NULL);
 	    }
@@ -810,8 +810,8 @@ Tcl_SplitList(
 	if (i >= size) {
 	    ckfree(argv);
 	    if (interp != NULL) {
-		Tcl_SetResult(interp, "internal error in Tcl_SplitList",
-			TCL_STATIC);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"internal error in Tcl_SplitList", -1));
 		Tcl_SetErrorCode(interp, "TCL", "INTERNAL", "Tcl_SplitList",
 			NULL);
 	    }
@@ -3382,16 +3382,10 @@ TclGetIntForIndex(
 
   parseError:
     if (interp != NULL) {
-	/*
-	 * The result might not be empty; this resets it which should be both
-	 * a cheap operation, and of little problem because this is an
-	 * error-generation path anyway.
-	 */
-
 	bytes = Tcl_GetString(objPtr);
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "bad index \"", bytes,
-		"\": must be integer?[+-]integer? or end?[+-]integer?", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"bad index \"%s\": must be integer?[+-]integer? or"
+		" end?[+-]integer?", bytes));
 	if (!strncmp(bytes, "end-", 4)) {
 	    bytes += 4;
 	}
@@ -3483,9 +3477,8 @@ SetEndOffsetFromAny(
     if ((*bytes != 'e') || (strncmp(bytes, "end",
 	    (size_t)((length > 3) ? 3 : length)) != 0)) {
 	if (interp != NULL) {
-	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "bad index \"", bytes,
-		    "\": must be end?[+-]integer?", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "bad index \"%s\": must be end?[+-]integer?", bytes));
 	    Tcl_SetErrorCode(interp, "TCL", "VALUE", "INDEX", NULL);
 	}
 	return TCL_ERROR;
@@ -3519,9 +3512,8 @@ SetEndOffsetFromAny(
 
     badIndexFormat:
 	if (interp != NULL) {
-	    Tcl_ResetResult(interp);
-	    Tcl_AppendResult(interp, "bad index \"", bytes,
-		    "\": must be end?[+-]integer?", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "bad index \"%s\": must be end?[+-]integer?", bytes));
 	    Tcl_SetErrorCode(interp, "TCL", "VALUE", "INDEX", NULL);
 	}
 	return TCL_ERROR;
@@ -3597,8 +3589,8 @@ TclCheckBadOctal(
 		 * be added to an existing error message as extra info.
 		 */
 
-		Tcl_AppendResult(interp, " (looks like invalid octal number)",
-			NULL);
+		Tcl_AppendToObj(Tcl_GetObjResult(interp),
+			" (looks like invalid octal number)", -1);
 	    }
 	    return 1;
 	}
@@ -4214,7 +4206,7 @@ TclReToGlob(
 
   invalidGlob:
     if (interp != NULL) {
-	Tcl_AppendResult(interp, msg, NULL);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(msg, -1));
 	Tcl_SetErrorCode(interp, "TCL", "RE2GLOB", code, NULL);
     }
     Tcl_DStringFree(dsPtr);
diff --git a/generic/tclVar.c b/generic/tclVar.c
index e92dc5f..e31e9cf 100644
--- a/generic/tclVar.c
+++ b/generic/tclVar.c
@@ -3065,7 +3065,8 @@ ArrayStartSearchCmd(
 
     if ((varPtr == NULL) || !TclIsVarArray(varPtr)
 	    || TclIsVarUndefined(varPtr)) {
-	Tcl_AppendResult(interp, "\"", varName, "\" isn't an array", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"\"%s\" isn't an array", varName));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ARRAY", varName, NULL);
 	return TCL_ERROR;
     }
@@ -3160,8 +3161,8 @@ ArrayAnyMoreCmd(
 
     if ((varPtr == NULL) || !TclIsVarArray(varPtr)
 	    || TclIsVarUndefined(varPtr)) {
-	Tcl_AppendResult(interp, "\"", TclGetString(varNameObj),
-		"\" isn't an array", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"\"%s\" isn't an array", TclGetString(varNameObj)));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ARRAY",
 		TclGetString(varNameObj), NULL);
 	return TCL_ERROR;
@@ -3266,8 +3267,8 @@ ArrayNextElementCmd(
 
     if ((varPtr == NULL) || !TclIsVarArray(varPtr)
 	    || TclIsVarUndefined(varPtr)) {
-	Tcl_AppendResult(interp, "\"", TclGetString(varNameObj),
-		"\" isn't an array", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"\"%s\" isn't an array", TclGetString(varNameObj)));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ARRAY",
 		TclGetString(varNameObj), NULL);
 	return TCL_ERROR;
@@ -3376,8 +3377,8 @@ ArrayDoneSearchCmd(
 
     if ((varPtr == NULL) || !TclIsVarArray(varPtr)
 	    || TclIsVarUndefined(varPtr)) {
-	Tcl_AppendResult(interp, "\"", TclGetString(varNameObj),
-		"\" isn't an array", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"\"%s\" isn't an array", TclGetString(varNameObj)));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ARRAY",
 		TclGetString(varNameObj), NULL);
 	return TCL_ERROR;
@@ -4019,8 +4020,8 @@ ArrayStatsCmd(
 
     if ((varPtr == NULL) || !TclIsVarArray(varPtr)
 	    || TclIsVarUndefined(varPtr)) {
-	Tcl_AppendResult(interp, "\"", TclGetString(varNameObj),
-		"\" isn't an array", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"\"%s\" isn't an array", TclGetString(varNameObj)));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ARRAY",
 		TclGetString(varNameObj), NULL);
 	return TCL_ERROR;
@@ -4028,7 +4029,8 @@ ArrayStatsCmd(
 
     stats = Tcl_HashStats((Tcl_HashTable *) varPtr->value.tablePtr);
     if (stats == NULL) {
-	Tcl_SetResult(interp, "error reading array statistics", TCL_STATIC);
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"error reading array statistics", -1));
 	return TCL_ERROR;
     }
     Tcl_SetObjResult(interp, Tcl_NewStringObj(stats, -1));
@@ -4317,10 +4319,10 @@ ObjMakeUpvar(
 			|| (varFramePtr == NULL)
 			|| !HasLocalVars(varFramePtr)
 			|| (strstr(TclGetString(myNamePtr), "::") != NULL))) {
-	    Tcl_AppendResult((Tcl_Interp *) iPtr, "bad variable name \"",
-		    TclGetString(myNamePtr), "\": upvar won't create "
+	    Tcl_SetObjResult((Tcl_Interp *) iPtr, Tcl_ObjPrintf(
+		    "bad variable name \"%s\": upvar won't create "
 		    "namespace variable that refers to procedure variable",
-		    NULL);
+		    TclGetString(myNamePtr)));
 	    Tcl_SetErrorCode(interp, "TCL", "UPVAR", "INVERTED", NULL);
 	    return TCL_ERROR;
 	}
@@ -4418,9 +4420,10 @@ TclPtrObjMakeUpvar(
 		 * myName looks like an array reference.
 		 */
 
-		Tcl_AppendResult((Tcl_Interp *) iPtr, "bad variable name \"",
-			myName, "\": upvar won't create a scalar variable "
-			"that looks like an array element", NULL);
+		Tcl_SetObjResult((Tcl_Interp *) iPtr, Tcl_ObjPrintf(
+			"bad variable name \"%s\": upvar won't create a"
+			" scalar variable that looks like an array element",
+			myName));
 		Tcl_SetErrorCode(interp, "TCL", "UPVAR", "LOCAL_ELEMENT",
 			NULL);
 		return TCL_ERROR;
@@ -4447,15 +4450,15 @@ TclPtrObjMakeUpvar(
     }
 
     if (varPtr == otherPtr) {
-	Tcl_SetResult((Tcl_Interp *) iPtr,
-		"can't upvar from variable to itself", TCL_STATIC);
+	Tcl_SetObjResult((Tcl_Interp *) iPtr, Tcl_NewStringObj(
+		"can't upvar from variable to itself", -1));
 	Tcl_SetErrorCode(interp, "TCL", "UPVAR", "SELF", NULL);
 	return TCL_ERROR;
     }
 
     if (TclIsVarTraced(varPtr)) {
-	Tcl_AppendResult((Tcl_Interp *) iPtr, "variable \"", myName,
-		"\" has traces: can't use for upvar", NULL);
+	Tcl_SetObjResult((Tcl_Interp *) iPtr, Tcl_ObjPrintf(
+		"variable \"%s\" has traces: can't use for upvar", myName));
 	Tcl_SetErrorCode(interp, "TCL", "UPVAR", "TRACED", NULL);
 	return TCL_ERROR;
     } else if (!TclIsVarUndefined(varPtr)) {
@@ -4469,8 +4472,8 @@ TclPtrObjMakeUpvar(
 	 */
 
 	if (!TclIsVarLink(varPtr)) {
-	    Tcl_AppendResult((Tcl_Interp *) iPtr, "variable \"", myName,
-		    "\" already exists", NULL);
+	    Tcl_SetObjResult((Tcl_Interp *) iPtr, Tcl_ObjPrintf(
+		    "variable \"%s\" already exists", myName));
 	    Tcl_SetErrorCode(interp, "TCL", "UPVAR", "EXISTS", NULL);
 	    return TCL_ERROR;
 	}
@@ -4968,8 +4971,8 @@ Tcl_UpvarObjCmd(
 	 * for this particular case.
 	 */
 
-	Tcl_AppendResult(interp, "bad level \"", TclGetString(levelObj), "\"",
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"bad level \"%s\"", TclGetString(levelObj)));
 	Tcl_SetErrorCode(interp, "TCL", "VALUE", "LEVEL", NULL);
 	return TCL_ERROR;
     }
@@ -4978,8 +4981,8 @@ Tcl_UpvarObjCmd(
      * We've now finished with parsing levels; skip to the variable names.
      */
 
-    objc -= hasLevel+1;
-    objv += hasLevel+1;
+    objc -= hasLevel + 1;
+    objv += hasLevel + 1;
 
     /*
      * Iterate over each (other variable, local variable) pair. Divide the
@@ -5060,8 +5063,8 @@ SetArraySearchObj(
     return TCL_OK;
 
   syntax:
-    Tcl_AppendResult(interp, "illegal search identifier \"", string, "\"",
-	    NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "illegal search identifier \"%s\"", string));
     Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ARRAYSEARCH", string, NULL);
     return TCL_ERROR;
 }
@@ -5126,10 +5129,9 @@ ParseSearchId(
      */
 
     if (strcmp(string+offset, varName) != 0) {
-	Tcl_AppendResult(interp, "search identifier \"", string,
-		"\" isn't for variable \"", varName, "\"", NULL);
-	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ARRAYSEARCH", string,
-		NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"search identifier \"%s\" isn't for variable \"%s\"",
+		string, varName));
 	goto badLookup;
     }
 
@@ -5153,7 +5155,8 @@ ParseSearchId(
 	    }
 	}
     }
-    Tcl_AppendResult(interp, "couldn't find search \"", string, "\"", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "couldn't find search \"%s\"", string));
   badLookup:
     Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ARRAYSEARCH", string, NULL);
     return NULL;
@@ -5894,8 +5897,8 @@ ObjFindNamespaceVar(
 	Tcl_DecrRefCount(simpleNamePtr);
     }
     if ((varPtr == NULL) && (flags & TCL_LEAVE_ERR_MSG)) {
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "unknown variable \"", name, "\"", NULL);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"unknown variable \"%s\"", name));
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "VARIABLE", name, NULL);
     }
     return (Tcl_Var) varPtr;
diff --git a/generic/tclZlib.c b/generic/tclZlib.c
index a799639..544fb6e 100644
--- a/generic/tclZlib.c
+++ b/generic/tclZlib.c
@@ -577,8 +577,8 @@ Tcl_ZlibStreamInit(
 	TclDStringAppendObj(&cmdname, Tcl_GetObjResult(interp));
 	if (Tcl_GetCommandInfo(interp, Tcl_DStringValue(&cmdname),
 		&cmdinfo) == 1) {
-	    Tcl_SetResult(interp,
-		    "BUG: Stream command name already exists", TCL_STATIC);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "BUG: Stream command name already exists", -1));
 	    Tcl_SetErrorCode(interp, "TCL", "BUG", "EXISTING_CMD", NULL);
 	    Tcl_DStringFree(&cmdname);
 	    goto error;
@@ -900,8 +900,8 @@ Tcl_ZlibStreamPut(
 
     if (zshPtr->streamEnd) {
 	if (zshPtr->interp) {
-	    Tcl_SetResult(zshPtr->interp,
-		    "already past compressed stream end", TCL_STATIC);
+	    Tcl_SetObjResult(zshPtr->interp, Tcl_NewStringObj(
+		    "already past compressed stream end", -1));
 	    Tcl_SetErrorCode(zshPtr->interp, "TCL", "ZIP", "CLOSED", NULL);
 	}
 	return TCL_ERROR;
@@ -1085,9 +1085,9 @@ Tcl_ZlibStreamGet(
 
 	    if (zshPtr->stream.avail_in > 0) {
 		if (zshPtr->interp) {
-		    Tcl_SetResult(zshPtr->interp,
-			"Unexpected zlib internal state during decompression",
-			TCL_STATIC);
+		    Tcl_SetObjResult(zshPtr->interp, Tcl_NewStringObj(
+			    "unexpected zlib internal state during"
+			    " decompression", -1));
 		    Tcl_SetErrorCode(zshPtr->interp, "TCL", "ZIP", "STATE",
 			    NULL);
 		}
@@ -1896,7 +1896,7 @@ ZlibCmd(
 	    format = TCL_ZLIB_FORMAT_GZIP;
 	    break;
 	default:
-	    Tcl_AppendResult(interp, "IMPOSSIBLE", NULL);
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj("impossible!", -1));
 	    return TCL_ERROR;
 	}
 
@@ -1910,16 +1910,16 @@ ZlibCmd(
 	 */
 
 	if (mode == TCL_ZLIB_STREAM_DEFLATE && !(chanMode & TCL_WRITABLE)) {
-	    Tcl_AppendResult(interp,
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "compression may only be applied to writable channels",
-		    NULL);
+		    -1));
 	    Tcl_SetErrorCode(interp, "TCL", "ZIP", "UNWRITABLE", NULL);
 	    return TCL_ERROR;
 	}
 	if (mode == TCL_ZLIB_STREAM_INFLATE && !(chanMode & TCL_READABLE)) {
-	    Tcl_AppendResult(interp,
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "decompression may only be applied to readable channels",
-		    NULL);
+		    -1));
 	    Tcl_SetErrorCode(interp, "TCL", "ZIP", "UNREADABLE", NULL);
 	    return TCL_ERROR;
 	}
@@ -1937,8 +1937,8 @@ ZlibCmd(
 	    switch ((enum pushOptions) option) {
 	    case poHeader:
 		if (++i > objc-1) {
-		    Tcl_AppendResult(interp,
-			    "value missing for -header option", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "value missing for -header option", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "ZIP", "NOVAL", NULL);
 		    return TCL_ERROR;
 		}
@@ -1950,8 +1950,8 @@ ZlibCmd(
 		break;
 	    case poLevel:
 		if (++i > objc-1) {
-		    Tcl_AppendResult(interp,
-			    "value missing for -level option", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "value missing for -level option", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "ZIP", "NOVAL", NULL);
 		    return TCL_ERROR;
 		}
@@ -1967,8 +1967,8 @@ ZlibCmd(
 		break;
 	    case poLimit:
 		if (++i > objc-1) {
-		    Tcl_AppendResult(interp,
-			    "value missing for -limit option", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "value missing for -limit option", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "ZIP", "NOVAL", NULL);
 		    return TCL_ERROR;
 		}
@@ -1996,14 +1996,15 @@ ZlibCmd(
     return TCL_ERROR;
 
   badLevel:
-    Tcl_AppendResult(interp, "level must be 0 to 9", NULL);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj("level must be 0 to 9", -1));
     Tcl_SetErrorCode(interp, "TCL", "VALUE", "COMPRESSIONLEVEL", NULL);
     if (extraInfoStr) {
 	Tcl_AddErrorInfo(interp, extraInfoStr);
     }
     return TCL_ERROR;
   badBuffer:
-    Tcl_AppendResult(interp, "buffer size must be 32 to 65536", NULL);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+	    "buffer size must be 32 to 65536", -1));
     Tcl_SetErrorCode(interp, "TCL", "VALUE", "BUFFERSIZE", NULL);
     return TCL_ERROR;
 }
@@ -2086,9 +2087,9 @@ ZlibStreamCmd(
 		break;
 	    case ao_buffer: /* -buffer */
 		if (i == objc-2) {
-		    Tcl_AppendResult(interp, "\"-buffer\" option must be "
-			    "followed by integer decompression buffersize",
-			    NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "\"-buffer\" option must be followed by integer"
+			    " decompression buffersize", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "ZIP", "NOVAL", NULL);
 		    return TCL_ERROR;
 		}
@@ -2097,8 +2098,8 @@ ZlibStreamCmd(
 		    return TCL_ERROR;
 		}
 		if (buffersize < 1 || buffersize > 65536) {
-		    Tcl_AppendResult(interp,
-			    "buffer size must be 32 to 65536", NULL);
+		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			    "buffer size must be 32 to 65536", -1));
 		    Tcl_SetErrorCode(interp, "TCL", "VALUE", "BUFFERSIZE",
 			    NULL);
 		    return TCL_ERROR;
@@ -2106,8 +2107,9 @@ ZlibStreamCmd(
 	    }
 
 	    if (flush == -2) {
-		Tcl_AppendResult(interp, "\"-flush\", \"-fullflush\" and "
-			"\"-finalize\" options are mutually exclusive", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"\"-flush\", \"-fullflush\" and \"-finalize\" options"
+			" are mutually exclusive", -1));
 		Tcl_SetErrorCode(interp, "TCL", "ZIP", "EXCLUSIVE", NULL);
 		return TCL_ERROR;
 	    }
@@ -2158,13 +2160,14 @@ ZlibStreamCmd(
 		}
 		break;
 	    case ao_buffer:
-		Tcl_AppendResult(interp,
-			"\"-buffer\" option not supported here", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"\"-buffer\" option not supported here", -1));
 		return TCL_ERROR;
 	    }
 	    if (flush == -2) {
-		Tcl_AppendResult(interp, "\"-flush\", \"-fullflush\" and "
-			"\"-finalize\" options are mutually exclusive", NULL);
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"\"-flush\", \"-fullflush\" and \"-finalize\" options"
+			" are mutually exclusive", -1));
 		Tcl_SetErrorCode(interp, "TCL", "ZIP", "EXCLUSIVE", NULL);
 		return TCL_ERROR;
 	    }
@@ -2314,9 +2317,9 @@ ZlibTransformClose(
 		     * then interp may be NULL */
 		    if (!TclInThreadExit()) {
 			if (interp) {
-			    Tcl_AppendResult(interp,
-				    "error while finalizing file: ",
-				    Tcl_PosixError(interp), NULL);
+			    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+				    "error while finalizing file: %s",
+				    Tcl_PosixError(interp)));
 			}
 		    }
 		    result = TCL_ERROR;
@@ -2581,8 +2584,9 @@ ZlibTransformSetOption(			/* not used */
 	} else if (value[0] == 's' && strcmp(value, "sync") == 0) {
 	    flushType = Z_SYNC_FLUSH;
 	} else {
-	    Tcl_AppendResult(interp, "unknown -flush type \"", value,
-		    "\": must be full or sync", NULL);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "unknown -flush type \"%s\": must be full or sync",
+		    value));
 	    Tcl_SetErrorCode(interp, "TCL", "VALUE", "FLUSH", NULL);
 	    return TCL_ERROR;
 	}
@@ -2610,8 +2614,9 @@ ZlibTransformSetOption(			/* not used */
 
 	    if (Tcl_WriteRaw(cd->parent, cd->outBuffer,
 		    cd->outStream.next_out - (Bytef *) cd->outBuffer) < 0) {
-		Tcl_AppendResult(interp, "problem flushing channel: ",
-			Tcl_PosixError(interp), NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"problem flushing channel: %s",
+			Tcl_PosixError(interp)));
 		return TCL_ERROR;
 	    }
 	}
@@ -3152,7 +3157,7 @@ Tcl_ZlibStreamInit(
     Tcl_Obj *dictObj,
     Tcl_ZlibStream *zshandle)
 {
-    Tcl_SetResult(interp, "unimplemented", TCL_STATIC);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj("unimplemented", -1));
     Tcl_SetErrorCode(interp, "TCL", "UNIMPLEMENTED", NULL);
     return TCL_ERROR;
 }
@@ -3218,7 +3223,7 @@ Tcl_ZlibDeflate(
     int level,
     Tcl_Obj *gzipHeaderDictObj)
 {
-    Tcl_SetResult(interp, "unimplemented", TCL_STATIC);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj("unimplemented", -1));
     Tcl_SetErrorCode(interp, "TCL", "UNIMPLEMENTED", NULL);
     return TCL_ERROR;
 }
@@ -3231,7 +3236,7 @@ Tcl_ZlibInflate(
     int bufferSize,
     Tcl_Obj *gzipHeaderDictObj)
 {
-    Tcl_SetResult(interp, "unimplemented", TCL_STATIC);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj("unimplemented", -1));
     Tcl_SetErrorCode(interp, "TCL", "UNIMPLEMENTED", NULL);
     return TCL_ERROR;
 }