Working towards adding all the Tcl_SetErrorCode calls that should be there.

** WORK IN PROGRESS **

35 files changed, 701 insertions, 446 deletions

diff --git a/generic/tk3d.c b/generic/tk3d.c
index 2920c76..dd7ab2f 100644
--- a/generic/tk3d.c
+++ b/generic/tk3d.c
@@ -673,11 +673,10 @@ Tk_GetRelief(
     } else if ((c == 's') && (strncmp(name, "sunken", length) == 0)) {
 	*reliefPtr = TK_RELIEF_SUNKEN;
     } else {
-	char buf[200];
-
-	sprintf(buf, "bad relief \"%.50s\": must be %s",
-		name, "flat, groove, raised, ridge, solid, or sunken");
-	Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	Tcl_SetObjResult(interp,
+		Tcl_ObjPrintf("bad relief \"%.50s\": must be %s",
+		name, "flat, groove, raised, ridge, solid, or sunken"));
+	Tcl_SetErrorCode(interp, "TK", "VALUE", "RELIEF", NULL);
 	return TCL_ERROR;
     }
     return TCL_OK;
diff --git a/generic/tkArgv.c b/generic/tkArgv.c
index 3f235ad..f4ddda4 100644
--- a/generic/tkArgv.c
+++ b/generic/tkArgv.c
@@ -70,7 +70,7 @@ Tk_ParseArgv(
     register const Tk_ArgvInfo *infoPtr;
 				/* Pointer to the current entry in the table
 				 * of argument descriptions. */
-    const Tk_ArgvInfo *matchPtr;	/* Descriptor that matches current argument. */
+    const Tk_ArgvInfo *matchPtr;/* Descriptor that matches current argument. */
     const char *curArg;		/* Current argument */
     register char c;		/* Second character of current arg (used for
 				 * quick check for matching; use 2nd char.
@@ -83,6 +83,7 @@ Tk_ParseArgv(
 				 * than srcIndex). */
     int argc;			/* # arguments in argv still to process. */
     size_t length;		/* Number of characters in current argument. */
+    char *endPtr;		/* Used for identifying junk in arguments. */
     int i;
 
     if (flags & TK_ARGV_DONT_SKIP_FIRST_ARG) {
@@ -139,8 +140,9 @@ Tk_ParseArgv(
 		    continue;
 		}
 		if (matchPtr != NULL) {
-		    Tcl_AppendResult(interp, "ambiguous option \"", curArg,
-			    "\"", NULL);
+		    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			    "ambiguous option \"%s\"", curArg));
+		    Tcl_SetErrorCode(interp, "TK", "ARG", "AMBIGUOUS", NULL);
 		    return TCL_ERROR;
 		}
 		matchPtr = infoPtr;
@@ -153,8 +155,9 @@ Tk_ParseArgv(
 	     */
 
 	    if (flags & TK_ARGV_NO_LEFTOVERS) {
-		Tcl_AppendResult(interp, "unrecognized argument \"",
-			curArg, "\"", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"unrecognized argument \"%s\"", curArg));
+		Tcl_SetErrorCode(interp, "TK", "ARG", "UNRECOGNIZED", NULL);
 		return TCL_ERROR;
 	    }
 	    argv[dstIndex] = curArg;
@@ -175,19 +178,17 @@ Tk_ParseArgv(
 	case TK_ARGV_INT:
 	    if (argc == 0) {
 		goto missingArg;
-	    } else {
-		char *endPtr;
-
-		*((int *) infoPtr->dst) = strtol(argv[srcIndex], &endPtr, 0);
-		if ((endPtr == argv[srcIndex]) || (*endPtr != 0)) {
-		    Tcl_AppendResult(interp,"expected integer argument for \"",
-			    infoPtr->key, "\" but got \"", argv[srcIndex],
-			    "\"", NULL);
-		    return TCL_ERROR;
-		}
-		srcIndex++;
-		argc--;
 	    }
+	    *((int *) infoPtr->dst) = strtol(argv[srcIndex], &endPtr, 0);
+	    if ((endPtr == argv[srcIndex]) || (*endPtr != 0)) {
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"expected %s argument for \"%s\" but got \"%s\"",
+			"integer", infoPtr->key, argv[srcIndex]));
+		Tcl_SetErrorCode(interp, "TK", "ARG", "INTEGER", NULL);
+		return TCL_ERROR;
+	    }
+	    srcIndex++;
+	    argc--;
 	    break;
 	case TK_ARGV_STRING:
 	    if (argc == 0) {
@@ -211,19 +212,17 @@ Tk_ParseArgv(
 	case TK_ARGV_FLOAT:
 	    if (argc == 0) {
 		goto missingArg;
-	    } else {
-		char *endPtr;
-
-		*((double *) infoPtr->dst) = strtod(argv[srcIndex], &endPtr);
-		if ((endPtr == argv[srcIndex]) || (*endPtr != 0)) {
-		    Tcl_AppendResult(interp, "expected floating-point ",
-			    "argument for \"", infoPtr->key, "\" but got \"",
-			    argv[srcIndex], "\"", NULL);
-		    return TCL_ERROR;
-		}
-		srcIndex++;
-		argc--;
 	    }
+	    *((double *) infoPtr->dst) = strtod(argv[srcIndex], &endPtr);
+	    if ((endPtr == argv[srcIndex]) || (*endPtr != 0)) {
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"expected %s argument for \"%s\" but got \"%s\"",
+			"floating-point", infoPtr->key, argv[srcIndex]));
+		Tcl_SetErrorCode(interp, "TK", "ARG", "FLOAT", NULL);
+		return TCL_ERROR;
+	    }
+	    srcIndex++;
+	    argc--;
 	    break;
 	case TK_ARGV_FUNC: {
 	    typedef int (ArgvFunc)(char *, const char *, const char *);
@@ -249,6 +248,7 @@ Tk_ParseArgv(
 	}
 	case TK_ARGV_HELP:
 	    PrintUsage(interp, argTable, flags);
+	    Tcl_SetErrorCode(interp, "TK", "ARG", "HELP", NULL);
 	    return TCL_ERROR;
 	case TK_ARGV_CONST_OPTION:
 	    Tk_AddOption(tkwin, infoPtr->dst, infoPtr->src,
@@ -265,8 +265,10 @@ Tk_ParseArgv(
 	    break;
 	case TK_ARGV_OPTION_NAME_VALUE:
 	    if (argc < 2) {
-		Tcl_AppendResult(interp, "\"", curArg,
-			"\" option requires two following arguments", NULL);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"\"%s\" option requires two following arguments",
+			curArg));
+		Tcl_SetErrorCode(interp, "TK", "ARG", "NAME_VALUE", NULL);
 		return TCL_ERROR;
 	    }
 	    Tk_AddOption(tkwin, argv[srcIndex], argv[srcIndex+1],
@@ -274,14 +276,12 @@ Tk_ParseArgv(
 	    srcIndex += 2;
 	    argc -= 2;
 	    break;
-	default: {
-	    char buf[64 + TCL_INTEGER_SPACE];
-
-	    sprintf(buf, "bad argument type %d in Tk_ArgvInfo", infoPtr->type);
-	    Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	default:
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "bad argument type %d in Tk_ArgvInfo", infoPtr->type));
+	    Tcl_SetErrorCode(interp, "TK", "ARG", "BAD_TYPE", NULL);
 	    return TCL_ERROR;
 	}
-	}
     }
 
     /*
@@ -301,8 +301,9 @@ Tk_ParseArgv(
     return TCL_OK;
 
   missingArg:
-    Tcl_AppendResult(interp, "\"", curArg,
-	    "\" option requires an additional argument", NULL);
+    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+	    "\"%s\" option requires an additional argument", curArg));
+    Tcl_SetErrorCode(interp, "TK", "ARG", "MISSING", NULL);
     return TCL_ERROR;
 }
 
diff --git a/generic/tkBind.c b/generic/tkBind.c
index e58ad4d..0c50368 100644
--- a/generic/tkBind.c
+++ b/generic/tkBind.c
@@ -2926,6 +2926,7 @@ HandleEventGenerate(
 	    || (mainPtr->mainPtr != ((TkWindow *) tkwin)->mainPtr)) {
 	Tcl_AppendResult(interp, "window id \"", Tcl_GetString(objv[0]),
 		"\" doesn't exist in this application", NULL);
+	Tcl_SetErrorCode(interp, "TK", "EVENT", "FOREIGN_TARGET", NULL);
 	return TCL_ERROR;
     }
 
@@ -2941,11 +2942,13 @@ HandleEventGenerate(
     if (count != 1) {
 	Tcl_SetResult(interp, "Double or Triple modifier not allowed",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "EVENT", "BAD_MODIFIER", NULL);
 	return TCL_ERROR;
     }
     if (*p != '\0') {
 	Tcl_SetResult(interp, "only one event specification allowed",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "EVENT", "MULTIPLE", NULL);
 	return TCL_ERROR;
     }
 
@@ -3023,6 +3026,7 @@ HandleEventGenerate(
 
 	    Tcl_AppendResult(interp, "value for \"", Tcl_GetString(optionPtr),
 		    "\" missing", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "EVENT", "MISSING_VALUE", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -3165,6 +3169,7 @@ HandleEventGenerate(
 	    if (keysym == NoSymbol) {
 		Tcl_AppendResult(interp, "unknown keysym \"", value, "\"",
 			NULL);
+		Tcl_SetErrorCode(interp, "TK", "LOOKUP", "KEYSYM", NULL);
 		return TCL_ERROR;
 	    }
 
@@ -3172,6 +3177,7 @@ HandleEventGenerate(
 	    if (event.general.xkey.keycode == 0) {
 		Tcl_AppendResult(interp, "no keycode for keysym \"", value,
 			"\"", NULL);
+		Tcl_SetErrorCode(interp, "TK", "LOOKUP", "KEYCODE", NULL);
 		return TCL_ERROR;
 	    }
 	    if (!(flags & KEY)
@@ -3402,6 +3408,7 @@ HandleEventGenerate(
     badopt:
 	Tcl_AppendResult(interp, name, " event doesn't accept \"",
 		Tcl_GetString(optionPtr), "\" option", NULL);
+	Tcl_SetErrorCode(interp, "TK", "EVENT", "BAD_OPTION", NULL);
 	return TCL_ERROR;
     }
 
@@ -3496,6 +3503,7 @@ NameToWindow(
 
   badWindow:
     Tcl_AppendResult(interp, "bad window name/identifier \"",name,"\"", NULL);
+    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "WINDOW_ID", NULL);
     return TCL_ERROR;
 }
 
@@ -3560,6 +3568,7 @@ GetVirtualEventUid(
 	    virtString[length - 2] != '>' || virtString[length - 1] != '>') {
 	Tcl_AppendResult(interp, "virtual event \"", virtString,
 		"\" is badly formed", NULL);
+	Tcl_SetErrorCode(interp, "TK", "EVENT", "VIRTUAL", "MALFORMED", NULL);
 	return NULL;
     }
     virtString[length - 2] = '\0';
@@ -3654,6 +3663,8 @@ FindSequence(
 		Tcl_SetResult(interp,
 			"virtual event not allowed in definition of another virtual event",
 			TCL_STATIC);
+		Tcl_SetErrorCode(interp, "TK", "EVENT", "VIRTUAL", "INNER",
+			NULL);
 		return NULL;
 	    }
 	    virtualFound = 1;
@@ -3680,11 +3691,14 @@ FindSequence(
 
     if (numPats == 0) {
 	Tcl_SetResult(interp, "no events specified in binding", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "EVENT", "NO_EVENTS", NULL);
 	return NULL;
     }
     if ((numPats > 1) && (virtualFound != 0)) {
 	Tcl_SetResult(interp, "virtual events may not be composed",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "EVENT", "VIRTUAL", "COMPOSITION",
+		NULL);
 	return NULL;
     }
 
@@ -3804,6 +3818,7 @@ ParseEventDescription(
 	    } else {
 		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
 			"bad ASCII character 0x%x", UCHAR(*p)));
+		Tcl_SetErrorCode(interp, "TK", "EVENT", "BAD_CHAR", NULL);
 		count = 0;
 		goto done;
 	    }
@@ -3846,12 +3861,16 @@ ParseEventDescription(
 	if (p == field) {
 	    Tcl_SetResult(interp, "virtual event \"<<>>\" is badly formed",
 		    TCL_STATIC);
+	    Tcl_SetErrorCode(interp, "TK", "EVENT", "VIRTUAL", "MALFORMED",
+		    NULL);
 	    count = 0;
 	    goto done;
 	}
 	if ((p == NULL) || (p[1] != '>')) {
 	    Tcl_SetResult(interp, "missing \">\" in virtual binding",
 		    TCL_STATIC);
+	    Tcl_SetErrorCode(interp, "TK", "EVENT", "VIRTUAL", "MALFORMED",
+		    NULL);
 	    count = 0;
 	    goto done;
 	}
@@ -3920,6 +3939,7 @@ ParseEventDescription(
 	    } else if ((eventFlags & BUTTON) == 0) {
 		Tcl_AppendResult(interp, "specified button \"", field,
 			"\" for non-button event", NULL);
+		Tcl_SetErrorCode(interp, "TK", "EVENT", "NON_BUTTON", NULL);
 		count = 0;
 		goto done;
 	    }
@@ -3931,6 +3951,7 @@ ParseEventDescription(
 	    if (patPtr->detail.keySym == NoSymbol) {
 		Tcl_AppendResult(interp, "bad event type or keysym \"",
 			field, "\"", NULL);
+		Tcl_SetErrorCode(interp, "TK", "LOOKUP", "KEYSYM", NULL);
 		count = 0;
 		goto done;
 	    }
@@ -3940,6 +3961,7 @@ ParseEventDescription(
 	    } else if ((eventFlags & KEY) == 0) {
 		Tcl_AppendResult(interp, "specified keysym \"", field,
 			"\" for non-key event", NULL);
+		Tcl_SetErrorCode(interp, "TK", "EVENT", "NON_KEY", NULL);
 		count = 0;
 		goto done;
 	    }
@@ -3947,6 +3969,7 @@ ParseEventDescription(
     } else if (eventFlags == 0) {
 	Tcl_SetResult(interp, "no event type or button # or keysym",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "EVENT", "UNMODIFIABLE", NULL);
 	count = 0;
 	goto done;
     }
@@ -3961,11 +3984,13 @@ ParseEventDescription(
 		Tcl_SetResult(interp,
 			"extra characters after detail in binding",
 			TCL_STATIC);
+		Tcl_SetErrorCode(interp, "TK", "EVENT", "PAST_DETAIL", NULL);
 		count = 0;
 		goto done;
 	    }
 	}
 	Tcl_SetResult(interp, "missing \">\" in binding", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "EVENT", "MALFORMED", NULL);
 	count = 0;
 	goto done;
     }
diff --git a/generic/tkBitmap.c b/generic/tkBitmap.c
index b0d1ecc..5349fd5 100644
--- a/generic/tkBitmap.c
+++ b/generic/tkBitmap.c
@@ -344,6 +344,7 @@ GetBitmap(
 	if (Tcl_IsSafe(interp)) {
 	    Tcl_AppendResult(interp, "can't specify bitmap with '@' in a",
 		    " safe interpreter", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "SAFE", "BITMAP_FILE", NULL);
 	    goto error;
 	}
 
@@ -365,6 +366,7 @@ GetBitmap(
 	    if (interp != NULL) {
 		Tcl_AppendResult(interp, "error reading bitmap file \"",
 			string, "\"", NULL);
+		Tcl_SetErrorCode(interp, "TK", "BITMAP", "FILE_ERROR", NULL);
 	    }
 	    Tcl_DStringFree(&buffer);
 	    goto error;
@@ -386,6 +388,7 @@ GetBitmap(
 		if (interp != NULL) {
 		    Tcl_AppendResult(interp, "bitmap \"", string,
 			    "\" not defined", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "BITMAP", NULL);
 		}
 		goto error;
 	    }
@@ -489,6 +492,7 @@ Tk_DefineBitmap(
     if (!isNew) {
 	Tcl_AppendResult(interp, "bitmap \"", name, "\" is already defined",
 		NULL);
+	Tcl_SetErrorCode(interp, "TK", "BITMAP", "EXISTS", NULL);
 	return TCL_ERROR;
     }
     predefPtr = ckalloc(sizeof(TkPredefBitmap));
diff --git a/generic/tkBusy.c b/generic/tkBusy.c
index fc7f6ab..5439969 100644
--- a/generic/tkBusy.c
+++ b/generic/tkBusy.c
@@ -689,6 +689,7 @@ GetBusy(
     if (hPtr == NULL) {
 	Tcl_AppendResult(interp, "can't find busy window \"",
 		Tcl_GetString(windowObj), "\"", NULL);
+	Tcl_SetErrorCode(interp, "TK", "LOOKUP", "BUSY", NULL);
 	return NULL;
     }
     return Tcl_GetHashValue(hPtr);
diff --git a/generic/tkCanvArc.c b/generic/tkCanvArc.c
index 6cbc89b..d8a8062 100644
--- a/generic/tkCanvArc.c
+++ b/generic/tkCanvArc.c
@@ -344,27 +344,21 @@ ArcCoords(
     ArcItem *arcPtr = (ArcItem *) itemPtr;
 
     if (objc == 0) {
-	Tcl_Obj *obj = Tcl_NewObj();
-	Tcl_Obj *subobj = Tcl_NewDoubleObj(arcPtr->bbox[0]);
-
-	Tcl_ListObjAppendElement(interp, obj, subobj);
-	subobj = Tcl_NewDoubleObj(arcPtr->bbox[1]);
-	Tcl_ListObjAppendElement(interp, obj, subobj);
-	subobj = Tcl_NewDoubleObj(arcPtr->bbox[2]);
-	Tcl_ListObjAppendElement(interp, obj, subobj);
-	subobj = Tcl_NewDoubleObj(arcPtr->bbox[3]);
-	Tcl_ListObjAppendElement(interp, obj, subobj);
-	Tcl_SetObjResult(interp, obj);
+	Tcl_Obj *objs[4];
+
+	objs[0] = Tcl_NewDoubleObj(arcPtr->bbox[0]);
+	objs[1] = Tcl_NewDoubleObj(arcPtr->bbox[1]);
+	objs[2] = Tcl_NewDoubleObj(arcPtr->bbox[2]);
+	objs[3] = Tcl_NewDoubleObj(arcPtr->bbox[3]);
+	Tcl_SetObjResult(interp, Tcl_NewListObj(4, objs));
     } else if ((objc == 1)||(objc == 4)) {
 	if (objc==1) {
 	    if (Tcl_ListObjGetElements(interp, objv[0], &objc,
 		    (Tcl_Obj ***) &objv) != TCL_OK) {
 		return TCL_ERROR;
 	    } else if (objc != 4) {
-		char buf[64 + TCL_INTEGER_SPACE];
-
-		sprintf(buf, "wrong # coordinates: expected 4, got %d", objc);
-		Tcl_SetResult(interp, buf, TCL_VOLATILE);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"wrong # coordinates: expected 4, got %d", objc));
 		return TCL_ERROR;
 	    }
 	}
@@ -380,10 +374,8 @@ ArcCoords(
 	}
 	ComputeArcBbox(canvas, arcPtr);
     } else {
-	char buf[64 + TCL_INTEGER_SPACE];
-
-	sprintf(buf, "wrong # coordinates: expected 0 or 4, got %d", objc);
-	Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"wrong # coordinates: expected 0 or 4, got %d", objc));
 	return TCL_ERROR;
     }
     return TCL_OK;
diff --git a/generic/tkCanvBmap.c b/generic/tkCanvBmap.c
index ea16a29..adaa184 100644
--- a/generic/tkCanvBmap.c
+++ b/generic/tkCanvBmap.c
@@ -249,10 +249,8 @@ BitmapCoords(
     if (objc == 0) {
 	Tcl_Obj *obj = Tcl_NewObj();
 
-	Tcl_Obj *subobj = Tcl_NewDoubleObj(bmapPtr->x);
-	Tcl_ListObjAppendElement(interp, obj, subobj);
-	subobj = Tcl_NewDoubleObj(bmapPtr->y);
-	Tcl_ListObjAppendElement(interp, obj, subobj);
+	Tcl_ListObjAppendElement(NULL, obj, Tcl_NewDoubleObj(bmapPtr->x));
+	Tcl_ListObjAppendElement(NULL, obj, Tcl_NewDoubleObj(bmapPtr->y));
 	Tcl_SetObjResult(interp, obj);
     } else if (objc < 3) {
 	if (objc == 1) {
@@ -260,10 +258,8 @@ BitmapCoords(
 		    (Tcl_Obj ***) &objv) != TCL_OK) {
 		return TCL_ERROR;
 	    } else if (objc != 2) {
-		char buf[64 + TCL_INTEGER_SPACE];
-
-		sprintf(buf, "wrong # coordinates: expected 2, got %d", objc);
-		Tcl_SetResult(interp, buf, TCL_VOLATILE);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"wrong # coordinates: expected 2, got %d", objc));
 		return TCL_ERROR;
 	    }
 	}
@@ -275,10 +271,8 @@ BitmapCoords(
 	}
 	ComputeBitmapBbox(canvas, bmapPtr);
     } else {
-	char buf[64 + TCL_INTEGER_SPACE];
-
-	sprintf(buf, "wrong # coordinates: expected 0 or 2, got %d", objc);
-	Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"wrong # coordinates: expected 0 or 2, got %d", objc));
 	return TCL_ERROR;
     }
     return TCL_OK;
diff --git a/generic/tkCanvImg.c b/generic/tkCanvImg.c
index 880070b..b92659b 100644
--- a/generic/tkCanvImg.c
+++ b/generic/tkCanvImg.c
@@ -232,23 +232,19 @@ ImageCoords(
     ImageItem *imgPtr = (ImageItem *) itemPtr;
 
     if (objc == 0) {
-	Tcl_Obj *obj = Tcl_NewObj();
+	Tcl_Obj *objs[2];
 
-	Tcl_Obj *subobj = Tcl_NewDoubleObj(imgPtr->x);
-	Tcl_ListObjAppendElement(interp, obj, subobj);
-	subobj = Tcl_NewDoubleObj(imgPtr->y);
-	Tcl_ListObjAppendElement(interp, obj, subobj);
-	Tcl_SetObjResult(interp, obj);
+	objs[0] = Tcl_NewDoubleObj(imgPtr->x);
+	objs[1] = Tcl_NewDoubleObj(imgPtr->y);
+	Tcl_SetObjResult(interp, Tcl_NewListObj(2, objs));
     } else if (objc < 3) {
 	if (objc==1) {
 	    if (Tcl_ListObjGetElements(interp, objv[0], &objc,
 		    (Tcl_Obj ***) &objv) != TCL_OK) {
 		return TCL_ERROR;
 	    } else if (objc != 2) {
-		char buf[64];
-
-		sprintf(buf, "wrong # coordinates: expected 2, got %d", objc);
-		Tcl_SetResult(interp, buf, TCL_VOLATILE);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"wrong # coordinates: expected 2, got %d", objc));
 		return TCL_ERROR;
 	    }
 	}
@@ -259,10 +255,8 @@ ImageCoords(
 	}
 	ComputeImageBbox(canvas, imgPtr);
     } else {
-	char buf[64];
-
-	sprintf(buf, "wrong # coordinates: expected 0 or 2, got %d", objc);
-	Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"wrong # coordinates: expected 0 or 2, got %d", objc));
 	return TCL_ERROR;
     }
     return TCL_OK;
diff --git a/generic/tkCanvLine.c b/generic/tkCanvLine.c
index 20a391e..e2dd8d3 100644
--- a/generic/tkCanvLine.c
+++ b/generic/tkCanvLine.c
@@ -391,54 +391,50 @@ LineCoords(
 	}
     }
     if (objc & 1) {
-	char buf[64 + TCL_INTEGER_SPACE];
-
-	sprintf(buf, "wrong # coordinates: expected an even number, got %d",
-		objc);
-	Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"wrong # coordinates: expected an even number, got %d",
+		objc));
 	return TCL_ERROR;
     } else if (objc < 4) {
-	char buf[64 + TCL_INTEGER_SPACE];
-
-	sprintf(buf, "wrong # coordinates: expected at least 4, got %d", objc);
-	Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"wrong # coordinates: expected at least 4, got %d", objc));
 	return TCL_ERROR;
-    } else {
-	numPoints = objc/2;
-	if (linePtr->numPoints != numPoints) {
-	    coordPtr = ckalloc(sizeof(double) * objc);
-	    if (linePtr->coordPtr != NULL) {
-		ckfree(linePtr->coordPtr);
-	    }
-	    linePtr->coordPtr = coordPtr;
-	    linePtr->numPoints = numPoints;
+    }
+
+    numPoints = objc/2;
+    if (linePtr->numPoints != numPoints) {
+	coordPtr = ckalloc(sizeof(double) * objc);
+	if (linePtr->coordPtr != NULL) {
+	    ckfree(linePtr->coordPtr);
 	}
-	coordPtr = linePtr->coordPtr;
-	for (i = 0; i < objc ; i++) {
-	    if (Tk_CanvasGetCoordFromObj(interp, canvas, objv[i],
-		    coordPtr++) != TCL_OK) {
-		return TCL_ERROR;
-	    }
+	linePtr->coordPtr = coordPtr;
+	linePtr->numPoints = numPoints;
+    }
+    coordPtr = linePtr->coordPtr;
+    for (i = 0; i < objc ; i++) {
+	if (Tk_CanvasGetCoordFromObj(interp, canvas, objv[i],
+		coordPtr++) != TCL_OK) {
+	    return TCL_ERROR;
 	}
+    }
 
-	/*
-	 * Update arrowheads by throwing away any existing arrow-head
-	 * information and calling ConfigureArrows to recompute it.
-	 */
+    /*
+     * Update arrowheads by throwing away any existing arrow-head information
+     * and calling ConfigureArrows to recompute it.
+     */
 
-	if (linePtr->firstArrowPtr != NULL) {
-	    ckfree(linePtr->firstArrowPtr);
-	    linePtr->firstArrowPtr = NULL;
-	}
-	if (linePtr->lastArrowPtr != NULL) {
-	    ckfree(linePtr->lastArrowPtr);
-	    linePtr->lastArrowPtr = NULL;
-	}
-	if (linePtr->arrow != ARROWS_NONE) {
-	    ConfigureArrows(canvas, linePtr);
-	}
-	ComputeLineBbox(canvas, linePtr);
+    if (linePtr->firstArrowPtr != NULL) {
+	ckfree(linePtr->firstArrowPtr);
+	linePtr->firstArrowPtr = NULL;
+    }
+    if (linePtr->lastArrowPtr != NULL) {
+	ckfree(linePtr->lastArrowPtr);
+	linePtr->lastArrowPtr = NULL;
+    }
+    if (linePtr->arrow != ARROWS_NONE) {
+	ConfigureArrows(canvas, linePtr);
     }
+    ComputeLineBbox(canvas, linePtr);
     return TCL_OK;
 }
 
@@ -1894,16 +1890,8 @@ ParseArrowShape(
     }
 
     if (Tcl_SplitList(interp, (char *) value, &argc, &argv) != TCL_OK) {
-	syntaxError:
-	Tcl_ResetResult(interp);
-	Tcl_AppendResult(interp, "bad arrow shape \"", value,
-		"\": must be list with three numbers", NULL);
-	if (argv != NULL) {
-	    ckfree(argv);
-	}
-	return TCL_ERROR;
-    }
-    if (argc != 3) {
+	goto syntaxError;
+    } else if (argc != 3) {
 	goto syntaxError;
     }
     if ((Tk_CanvasGetCoord(interp, linePtr->canvas, argv[0], &a) != TCL_OK)
@@ -1913,11 +1901,21 @@ ParseArrowShape(
 		!= TCL_OK)) {
 	goto syntaxError;
     }
+
     linePtr->arrowShapeA = (float) a;
     linePtr->arrowShapeB = (float) b;
     linePtr->arrowShapeC = (float) c;
     ckfree(argv);
     return TCL_OK;
+
+  syntaxError:
+    Tcl_ResetResult(interp);
+    Tcl_AppendResult(interp, "bad arrow shape \"", value,
+	    "\": must be list with three numbers", NULL);
+    if (argv != NULL) {
+	ckfree(argv);
+    }
+    return TCL_ERROR;
 }
 
 /*
diff --git a/generic/tkCanvPs.c b/generic/tkCanvPs.c
index eafc07f..69c9cfb 100644
--- a/generic/tkCanvPs.c
+++ b/generic/tkCanvPs.c
@@ -548,11 +548,9 @@ TkCanvPostscriptCmd(
 	result = itemPtr->typePtr->postscriptProc(interp,
 		(Tk_Canvas) canvasPtr, itemPtr, 0);
 	if (result != TCL_OK) {
-	    char msg[64 + TCL_INTEGER_SPACE];
-
-	    sprintf(msg, "\n    (generating Postscript for item %d)",
-		    itemPtr->id);
-	    Tcl_AddErrorInfo(interp, msg);
+	    Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
+		    "\n    (generating Postscript for item %d)",
+		    itemPtr->id));
 	    goto cleanup;
 	}
 	Tcl_AppendResult(interp, "grestore\n", NULL);
diff --git a/generic/tkCanvWind.c b/generic/tkCanvWind.c
index f2cce7d..0c54741 100644
--- a/generic/tkCanvWind.c
+++ b/generic/tkCanvWind.c
@@ -246,22 +246,19 @@ WinItemCoords(
     WindowItem *winItemPtr = (WindowItem *) itemPtr;
 
     if (objc == 0) {
-	Tcl_Obj *obj = Tcl_NewObj();
-	Tcl_Obj *subobj = Tcl_NewDoubleObj(winItemPtr->x);
-	Tcl_ListObjAppendElement(interp, obj, subobj);
-	subobj = Tcl_NewDoubleObj(winItemPtr->y);
-	Tcl_ListObjAppendElement(interp, obj, subobj);
-	Tcl_SetObjResult(interp, obj);
+	Tcl_Obj *objs[2];
+
+	objs[0] = Tcl_NewDoubleObj(winItemPtr->x);
+	objs[1] = Tcl_NewDoubleObj(winItemPtr->y);
+	Tcl_SetObjResult(interp, Tcl_NewListObj(2, objs));
     } else if (objc < 3) {
 	if (objc==1) {
 	    if (Tcl_ListObjGetElements(interp, objv[0], &objc,
 		    (Tcl_Obj ***) &objv) != TCL_OK) {
 		return TCL_ERROR;
 	    } else if (objc != 2) {
-		char buf[64 + TCL_INTEGER_SPACE];
-
-		sprintf(buf, "wrong # coordinates: expected 2, got %d", objc);
-		Tcl_SetResult(interp, buf, TCL_VOLATILE);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"wrong # coordinates: expected 2, got %d", objc));
 		return TCL_ERROR;
 	    }
 	}
@@ -272,10 +269,8 @@ WinItemCoords(
 	}
 	ComputeWindowBbox(canvas, winItemPtr);
     } else {
-	char buf[64 + TCL_INTEGER_SPACE];
-
-	sprintf(buf, "wrong # coordinates: expected 0 or 2, got %d", objc);
-	Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"wrong # coordinates: expected 0 or 2, got %d", objc));
 	return TCL_ERROR;
     }
     return TCL_OK;
diff --git a/generic/tkColor.c b/generic/tkColor.c
index 9383a92..b1ed4f1 100644
--- a/generic/tkColor.c
+++ b/generic/tkColor.c
@@ -226,9 +226,11 @@ Tk_GetColor(
 	    if (*name == '#') {
 		Tcl_AppendResult(interp, "invalid color name \"", name,
 			"\"", NULL);
+		Tcl_SetErrorCode(interp, "TK", "VALUE", "COLOR", NULL);
 	    } else {
 		Tcl_AppendResult(interp, "unknown color name \"", name,
 			"\"", NULL);
+		Tcl_SetErrorCode(interp, "TK", "LOOKUP", "COLOR", name, NULL);
 	    }
 	}
 	if (isNew) {
@@ -372,10 +374,12 @@ Tk_NameOfColor(
 	sprintf(tsdPtr->rgbString, "#%04x%04x%04x", colorPtr->red,
 		colorPtr->green, colorPtr->blue);
 
-	/* If the string has the form #RSRSTUTUVWVW (where equal
-	 * letters denote equal hexdigits) then this is
-	 * equivalent to #RSTUVW. Then output the shorter form.
+	/*
+	 * If the string has the form #RSRSTUTUVWVW (where equal letters
+	 * denote equal hexdigits) then this is equivalent to #RSTUVW. Then
+	 * output the shorter form.
 	 */
+
 	if ((tsdPtr->rgbString[1] == tsdPtr->rgbString[3])
 		&& (tsdPtr->rgbString[2] == tsdPtr->rgbString[4])
 		&& (tsdPtr->rgbString[5] == tsdPtr->rgbString[7])
diff --git a/generic/tkConfig.c b/generic/tkConfig.c
index 5262f58..51ac6dc 100644
--- a/generic/tkConfig.c
+++ b/generic/tkConfig.c
@@ -946,16 +946,13 @@ DoObjConfig(
 	break;
     }
 
-    {
-	char buf[40+TCL_INTEGER_SPACE];
-
     default:
-	sprintf(buf, "bad config table: unknown type %d",
-		optionPtr->specPtr->type);
-	Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"bad config table: unknown type %d",
+		optionPtr->specPtr->type));
+	Tcl_SetErrorCode(interp, "TK", "BAD_CONFIG", NULL);
 	return TCL_ERROR;
     }
-    }
 
     /*
      * Release resources associated with the old value, if we're not returning
@@ -1162,6 +1159,7 @@ GetOptionFromObj(
   error:
     if (interp != NULL) {
 	Tcl_AppendResult(interp, "unknown option \"", name, "\"", NULL);
+	Tcl_SetErrorCode(interp, "TK", "LOOKUP", "OPTION", name, NULL);
     }
     return NULL;
 }
@@ -1231,9 +1229,10 @@ SetOptionFromAny(
     Tcl_AppendResult(interp,
 	    "can't convert value to option except via GetOptionFromObj API",
 	    NULL);
+    Tcl_SetErrorCode(interp, "TK", "API_ABUSE", NULL);
     return TCL_ERROR;
 }
-
+
 /*
  *----------------------------------------------------------------------
  *
@@ -1348,6 +1347,7 @@ Tk_SetOptions(
 	    if (interp != NULL) {
 		Tcl_AppendResult(interp, "value for \"",
 			Tcl_GetStringFromObj(*objv, NULL), "\" missing",NULL);
+		Tcl_SetErrorCode(interp, "TK", "VALUE_MISSING", NULL);
 		goto error;
 	    }
 	}
@@ -1369,11 +1369,9 @@ Tk_SetOptions(
 	if (DoObjConfig(interp, recordPtr, optionPtr, objv[1], tkwin,
 		(savePtr != NULL) ? &lastSavePtr->items[lastSavePtr->numItems]
 		: NULL) != TCL_OK) {
-	    char msg[100];
-
-	    sprintf(msg, "\n    (processing \"%.40s\" option)",
-		    Tcl_GetStringFromObj(*objv, NULL));
-	    Tcl_AddErrorInfo(interp, msg);
+	    Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
+		    "\n    (processing \"%.40s\" option)",
+		    Tcl_GetStringFromObj(*objv, NULL)));
 	    goto error;
 	}
 	if (savePtr != NULL) {
@@ -1771,7 +1769,6 @@ FreeResources(
  *	single option or all the configuration options in a table.
  *
  * Results:
-
  *	This function normally returns a pointer to an object. If namePtr
  *	isn't NULL, then the result object is a list with five elements: the
  *	option's name, its database name, database class, default value, and
@@ -2154,8 +2151,7 @@ TkDebugConfig(
     Tcl_Obj *objPtr;
 
     objPtr = Tcl_NewObj();
-    hashTablePtr = (Tcl_HashTable *) Tcl_GetAssocData(interp, OPTION_HASH_KEY,
-	    NULL);
+    hashTablePtr = Tcl_GetAssocData(interp, OPTION_HASH_KEY, NULL);
     if (hashTablePtr == NULL) {
 	return objPtr;
     }
diff --git a/generic/tkEntry.c b/generic/tkEntry.c
index 044a35b..39aa228 100644
--- a/generic/tkEntry.c
+++ b/generic/tkEntry.c
@@ -2935,10 +2935,9 @@ EntryUpdateScrollbar(
     code = Tcl_VarEval(interp, entryPtr->scrollCmd, " ", firstStr, " ",
 	    lastStr, NULL);
     if (code != TCL_OK) {
-	Tcl_AddErrorInfo(interp,
-		"\n    (horizontal scrolling command executed by ");
-	Tcl_AddErrorInfo(interp, Tk_PathName(entryPtr->tkwin));
-	Tcl_AddErrorInfo(interp, ")");
+	Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
+		"\n    (horizontal scrolling command executed by %s)",
+		Tk_PathName(entryPtr->tkwin)));
 	Tcl_BackgroundException(interp, code);
     }
     Tcl_ResetResult(interp);
@@ -3141,7 +3140,7 @@ EntryValidate(
 
     if (code != TCL_OK && code != TCL_RETURN) {
 	Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
-		"\n\t(in validation command executed by %s)",
+		"\n    (in validation command executed by %s)",
 		Tk_PathName(entryPtr->tkwin)));
 	Tcl_BackgroundException(interp, code);
 	return TCL_ERROR;
@@ -3154,7 +3153,7 @@ EntryValidate(
     if (Tcl_GetBooleanFromObj(interp, Tcl_GetObjResult(interp),
 	    &bool) != TCL_OK) {
 	Tcl_AddErrorInfo(interp,
-		 "\nvalid boolean not returned by validation command");
+		 "\n    (invalid boolean result from validation command)");
 	Tcl_BackgroundError(interp);
 	Tcl_ResetResult(interp);
 	return TCL_ERROR;
@@ -3280,7 +3279,7 @@ EntryValidateChange(
 		    TCL_EVAL_GLOBAL | TCL_EVAL_DIRECT);
 	    if (result != TCL_OK) {
 		Tcl_AddErrorInfo(entryPtr->interp,
-			"\n\t(in invalidcommand executed by entry)");
+			"\n    (in invalidcommand executed by entry)");
 		Tcl_BackgroundException(entryPtr->interp, result);
 		code = TCL_ERROR;
 		entryPtr->validate = VALIDATE_NONE;
@@ -4284,7 +4283,8 @@ SpinboxInvoke(
 	Tcl_DStringFree(&script);
 
 	if (code != TCL_OK) {
-	    Tcl_AddErrorInfo(interp, "\n\t(in command executed by spinbox)");
+	    Tcl_AddErrorInfo(interp,
+		    "\n    (in command executed by spinbox)");
 	    Tcl_BackgroundException(interp, code);
 
 	    /*
diff --git a/generic/tkFont.c b/generic/tkFont.c
index 32d0589..e536c41 100644
--- a/generic/tkFont.c
+++ b/generic/tkFont.c
@@ -569,6 +569,7 @@ Tk_FontObjCmd(
 			-1, 40, "...");
 		Tcl_AppendToObj(resultPtr, "\"", -1);
 		Tcl_SetObjResult(interp, resultPtr);
+		Tcl_SetErrorCode(interp, "TK", "VALUE", "FONT_SAMPLE", NULL);
 		return TCL_ERROR;
 	    }
 	    uniChar = Tcl_GetUniChar(charPtr, 0);
@@ -618,6 +619,7 @@ Tk_FontObjCmd(
 	if ((namedHashPtr == NULL) || (nfPtr->deletePending != 0)) {
 	    Tcl_AppendResult(interp, "named font \"", string,
 		    "\" doesn't exist", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "FONT", string, NULL);
 	    return TCL_ERROR;
 	}
 	if (objc == 3) {
@@ -951,6 +953,7 @@ TkCreateNamedFont(
 	    if (interp) {
 		Tcl_AppendResult(interp, "named font \"", name,
 			"\" already exists", NULL);
+		Tcl_SetErrorCode(interp, "TK", "FONT", "EXISTS", NULL);
 	    }
 	    return TCL_ERROR;
 	}
@@ -1002,6 +1005,7 @@ TkDeleteNamedFont(
 	if (interp) {
 	    Tcl_AppendResult(interp, "named font \"", name,
 		    "\" doesn't exist", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "FONT", name, NULL);
 	}
 	return TCL_ERROR;
     }
@@ -1185,6 +1189,7 @@ Tk_AllocFontFromObj(
 	}
 	Tcl_AppendResult(interp, "failed to allocate font due to ",
 		"internal system font engine problem", NULL);
+	Tcl_SetErrorCode(interp, "TK", "FONT", "INTERNAL_PROBLEM", NULL);
 	return NULL;
     }
 
@@ -3405,6 +3410,7 @@ ConfigAttributesObj(
 	    if (interp != NULL) {
 		Tcl_AppendResult(interp, "value for \"",
 			Tcl_GetString(optionPtr), "\" option missing", NULL);
+		Tcl_SetErrorCode(interp, "TK", "FONT", "NO_ATTRIBUTE", NULL);
 	    }
 	    return TCL_ERROR;
 	}
@@ -3648,6 +3654,7 @@ ParseFontNameObj(
 	if (interp != NULL) {
 	    Tcl_AppendResult(interp, "font \"", string, "\" doesn't exist",
 		    NULL);
+	    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "FONT", string, NULL);
 	}
 	return TCL_ERROR;
     }
@@ -3696,6 +3703,8 @@ ParseFontNameObj(
 	if (interp != NULL) {
 	    Tcl_AppendResult(interp, "unknown font style \"",
 		    Tcl_GetString(objv[i]), "\"", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "FONT_STYLE",
+		    Tcl_GetString(objv[i]), NULL);
 	}
 	return TCL_ERROR;
     }
@@ -4077,7 +4086,6 @@ TkFontGetPoints(
  *	platform expects when asking for the font.
  *
  * Results:
-
  *	As above. The return value is NULL if the font name has no aliases.
  *
  * Side effects:
diff --git a/generic/tkGrab.c b/generic/tkGrab.c
index 695690b..9e9daae 100644
--- a/generic/tkGrab.c
+++ b/generic/tkGrab.c
@@ -215,6 +215,7 @@ Tk_GrabObjCmd(
 	Tcl_AppendResult(interp, "wrong # args: should be \"",
 		Tcl_GetString(objv[0]), " ?-global? window\" or \"",
 		Tcl_GetString(objv[0]), " option ?arg ...?\"", NULL);
+	Tcl_SetErrorCode(interp, "TCL", "WRONGARGS", NULL);
 	return TCL_ERROR;
     }
 
@@ -410,10 +411,7 @@ Tk_Grab(
 	    return TCL_OK;
 	}
 	if (dispPtr->eventualGrabWinPtr->mainPtr != winPtr->mainPtr) {
-	alreadyGrabbed:
-	    Tcl_SetResult(interp, "grab failed: another application has grab",
-		    TCL_STATIC);
-	    return TCL_ERROR;
+	    goto alreadyGrabbed;
 	}
 	Tk_Ungrab((Tk_Window) dispPtr->eventualGrabWinPtr);
     }
@@ -423,7 +421,7 @@ Tk_Grab(
     if (!grabGlobal)
 #else
     if (0)
-#endif
+#endif /* MAC_OSX_TK */
     {
 	Window dummy1, dummy2;
 	int dummy3, dummy4, dummy5, dummy6;
@@ -479,26 +477,7 @@ Tk_Grab(
 	    Tcl_Sleep(100);
 	}
 	if (grabResult != 0) {
-	grabError:
-	    if (grabResult == GrabNotViewable) {
-		Tcl_SetResult(interp, "grab failed: window not viewable",
-			TCL_STATIC);
-	    } else if (grabResult == AlreadyGrabbed) {
-		goto alreadyGrabbed;
-	    } else if (grabResult == GrabFrozen) {
-		Tcl_SetResult(interp,
-			"grab failed: keyboard or pointer frozen", TCL_STATIC);
-	    } else if (grabResult == GrabInvalidTime) {
-		Tcl_SetResult(interp, "grab failed: invalid time",
-			TCL_STATIC);
-	    } else {
-		char msg[64 + TCL_INTEGER_SPACE];
-
-		sprintf(msg, "grab failed for unknown reason (code %d)",
-			grabResult);
-		Tcl_AppendResult(interp, msg, NULL);
-	    }
-	    return TCL_ERROR;
+	    goto grabError;
 	}
 	grabResult = XGrabKeyboard(dispPtr->display, Tk_WindowId(tkwin),
 		False, GrabModeAsync, GrabModeAsync, CurrentTime);
@@ -546,6 +525,29 @@ Tk_Grab(
     }
     QueueGrabWindowChange(dispPtr, winPtr);
     return TCL_OK;
+
+  grabError:
+    if (grabResult == GrabNotViewable) {
+	Tcl_SetResult(interp, "grab failed: window not viewable", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "GRAB", "UNVIEWABLE", NULL);
+    } else if (grabResult == AlreadyGrabbed) {
+    alreadyGrabbed:
+	Tcl_SetResult(interp, "grab failed: another application has grab",
+		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "GRAB", "GRABBED", NULL);
+    } else if (grabResult == GrabFrozen) {
+	Tcl_SetResult(interp,
+		"grab failed: keyboard or pointer frozen", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "GRAB", "FROZEN", NULL);
+    } else if (grabResult == GrabInvalidTime) {
+	Tcl_SetResult(interp, "grab failed: invalid time", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "GRAB", "BADTIME", NULL);
+    } else {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"grab failed for unknown reason (code %d)", grabResult));
+	Tcl_SetErrorCode(interp, "TK", "GRAB", "UNKNOWN", NULL);
+    }
+    return TCL_ERROR;
 }
 
 /*
diff --git a/generic/tkGrid.c b/generic/tkGrid.c
index 70d463e..627bb89 100644
--- a/generic/tkGrid.c
+++ b/generic/tkGrid.c
@@ -402,7 +402,7 @@ Tk_GridObjCmd(
     }
 
     /* This should not happen */
-    Tcl_SetResult(interp, "Internal error in grid.", TCL_STATIC);
+    Tcl_SetResult(interp, "internal error in grid", TCL_STATIC);
     return TCL_ERROR;
 }
 
@@ -997,6 +997,7 @@ GridRowColumnConfigureCommand(
 	Tcl_AppendResult(interp, "no ",
 		(slotType == COLUMN) ? "column" : "row",
 		" indices specified", NULL);
+	Tcl_SetErrorCode(interp, "TK", "GRID", "NOINDEX", NULL);
 	Tcl_DecrRefCount(listCopy);
 	return TCL_ERROR;
     }
@@ -1010,6 +1011,7 @@ GridRowColumnConfigureCommand(
 	    Tcl_AppendResult(interp, Tcl_GetString(objv[0]), " ",
 		    Tcl_GetString(objv[1]),
 		    ": must specify a single element on retrieval", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GRID", "USAGE", NULL);
 	    Tcl_DecrRefCount(listCopy);
 	    return TCL_ERROR;
 	}
@@ -1017,6 +1019,7 @@ GridRowColumnConfigureCommand(
 	    Tcl_AppendResult(interp,
 		    " (when retreiving options only integer indices are "
 		    "allowed)", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GRID", "INDEX_FORMAT", NULL);
 	    Tcl_DecrRefCount(listCopy);
 	    return TCL_ERROR;
 	}
@@ -1122,6 +1125,7 @@ GridRowColumnConfigureCommand(
 			Tcl_GetString(objv[1]), ": the window \"",
 			Tcl_GetString(lObjv[j]), "\" is not managed by \"",
 		 	Tcl_GetString(objv[2]), "\"", NULL);
+		Tcl_SetErrorCode(interp, "TK", "LOOKUP", "GRID_MASTER", NULL);
 		Tcl_DecrRefCount(listCopy);
 		return TCL_ERROR;
 	    }
@@ -1129,6 +1133,7 @@ GridRowColumnConfigureCommand(
 	    Tcl_AppendResult(interp, Tcl_GetString(objv[0]), " ",
 		    Tcl_GetString(objv[1]), ": illegal index \"",
 		    Tcl_GetString(lObjv[j]), "\"", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "VALUE", "GRID_INDEX", NULL);
 	    Tcl_DecrRefCount(listCopy);
 	    return TCL_ERROR;
 	}
@@ -1152,6 +1157,7 @@ GridRowColumnConfigureCommand(
 			    Tcl_GetString(objv[1]), ": \"",
 			    Tcl_GetString(lObjv[j]),
 			    "\" is out of range", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "GRID", "INDEX_RANGE", NULL);
 		    Tcl_DecrRefCount(listCopy);
 		    return TCL_ERROR;
 		}
@@ -1189,6 +1195,8 @@ GridRowColumnConfigureCommand(
 				    Tcl_GetString(objv[i]),
 				    "\": should be non-negative", NULL);
 			    Tcl_DecrRefCount(listCopy);
+			    Tcl_SetErrorCode(interp, "TK", "GRID",
+				    "NEG_INDEX", NULL);
 			    return TCL_ERROR;
 			} else {
 			    slotPtr[slot].weight = wt;
@@ -1209,6 +1217,8 @@ GridRowColumnConfigureCommand(
 			    Tcl_AppendResult(interp, "invalid arg \"",
 				    Tcl_GetString(objv[i]),
 				    "\": should be non-negative", NULL);
+			    Tcl_SetErrorCode(interp, "TK", "GRID",
+				    "NEG_INDEX", NULL);
 			    Tcl_DecrRefCount(listCopy);
 			    return TCL_ERROR;
 			} else {
@@ -1363,6 +1373,7 @@ GridSlavesCommand(
 	if (value < 0) {
 	    Tcl_AppendResult(interp, Tcl_GetString(objv[i]),
 		    " is an invalid value: should NOT be < 0", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GRID", "NEG_INDEX", NULL);
 	    return TCL_ERROR;
 	}
 	if (index == SLAVES_COLUMN) {
@@ -2529,6 +2540,7 @@ SetSlaveColumn(
     lastCol = ((newColumn >= 0) ? newColumn : 0) + newNumCols;
     if (lastCol >= MAX_ELEMENT) {
 	Tcl_SetResult(interp, "Column out of bounds", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "GRID", "BAD_COLUMN", NULL);
 	return TCL_ERROR;
     }
 
@@ -2569,6 +2581,7 @@ SetSlaveRow(
     lastRow = ((newRow >= 0) ? newRow : 0) + newNumRows;
     if (lastRow >= MAX_ELEMENT) {
 	Tcl_SetResult(interp, "Row out of bounds", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "GRID", "BAD_ROW", NULL);
 	return TCL_ERROR;
     }
 
@@ -2994,6 +3007,7 @@ ConfigureSlaves(
 	if (length > 1 && i == 0) {
 	    Tcl_AppendResult(interp, "bad argument \"", string,
 		    "\": must be name of window", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GRID", "BAD_PARAMETER", NULL);
 	    return TCL_ERROR;
 	}
     	if (length > 1 && firstChar == '-') {
@@ -3003,6 +3017,7 @@ ConfigureSlaves(
 	    Tcl_AppendResult(interp, "unexpected parameter, \"",
 		    string, "\", in configure list. ",
 		    "Should be window name or option", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GRID", "BAD_PARAMETER", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -3010,6 +3025,7 @@ ConfigureSlaves(
 		(prevChar == REL_SKIP) || (prevChar == REL_VERT))) {
 	    Tcl_AppendResult(interp,
 		    "Must specify window before shortcut '-'.", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GRID", "SHORTCUT_USAGE", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -3020,12 +3036,14 @@ ConfigureSlaves(
 
 	Tcl_AppendResult(interp, "invalid window shortcut, \"",
 		string, "\" should be '-', 'x', or '^'", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GRID", "SHORTCUT_USAGE", NULL);
 	return TCL_ERROR;
     }
     numWindows = i;
 
     if ((objc - numWindows) & 1) {
 	Tcl_AppendResult(interp, "extra option or option with no value", NULL);
+	Tcl_SetErrorCode(interp, "TK", "GRID", "BAD_PARAMETER", NULL);
 	return TCL_ERROR;
     }
 
@@ -3055,6 +3073,7 @@ ConfigureSlaves(
 		Tcl_AppendResult(interp, "bad row value \"",
 			Tcl_GetString(objv[i+1]), "\": must be ",
 			"a non-negative integer", NULL);
+		Tcl_SetErrorCode(interp, "TK", "VALUE", "POSITIVE_INT", NULL);
 		return TCL_ERROR;
 	    }
 	    defaultRow = tmp;
@@ -3118,6 +3137,7 @@ ConfigureSlaves(
 	if (Tk_TopWinHierarchy(slave)) {
 	    Tcl_AppendResult(interp, "can't manage \"", Tcl_GetString(objv[j]),
 		    "\": it's a top-level window", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GEOMETRY", "TOPLEVEL", NULL);
 	    return TCL_ERROR;
 	}
 	slavePtr = GetGrid(slave);
@@ -3147,6 +3167,7 @@ ConfigureSlaves(
 		    Tcl_AppendResult(interp, "bad column value \"",
 			    Tcl_GetString(objv[i+1]), "\": must be ",
 			    "a non-negative integer", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "VALUE", "COLUMN", NULL);
 		    return TCL_ERROR;
 		}
 		if (SetSlaveColumn(interp, slavePtr, tmp, -1) != TCL_OK) {
@@ -3159,6 +3180,7 @@ ConfigureSlaves(
 		    Tcl_AppendResult(interp, "bad columnspan value \"",
 			    Tcl_GetString(objv[i+1]), "\": must be ",
 			    "a positive integer", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "VALUE", "SPAN", NULL);
 		    return TCL_ERROR;
 		}
 		if (SetSlaveColumn(interp, slavePtr, -1, tmp) != TCL_OK) {
@@ -3173,6 +3195,7 @@ ConfigureSlaves(
 		if (other == slave) {
 		    Tcl_SetResult(interp, "Window can't be managed in itself",
 			    TCL_STATIC);
+		    Tcl_SetErrorCode(interp, "TK", "GEOMETRY", "SELF", NULL);
 		    return TCL_ERROR;
 		}
 		positionGiven = 1;
@@ -3186,6 +3209,7 @@ ConfigureSlaves(
 		    Tcl_AppendResult(interp, "bad stickyness value \"",
 			    Tcl_GetString(objv[i+1]), "\": must be ",
 			    "a string containing n, e, s, and/or w", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "VALUE", "STICKY", NULL);
 		    return TCL_ERROR;
 		}
 		slavePtr->sticky = sticky;
@@ -3197,6 +3221,7 @@ ConfigureSlaves(
 		    Tcl_AppendResult(interp, "bad ipadx value \"",
 			    Tcl_GetString(objv[i+1]), "\": must be ",
 			    "positive screen distance", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "VALUE", "INT_PAD", NULL);
 		    return TCL_ERROR;
 		}
 		slavePtr->iPadX = tmp * 2;
@@ -3207,6 +3232,7 @@ ConfigureSlaves(
 		    Tcl_AppendResult(interp, "bad ipady value \"",
 			    Tcl_GetString(objv[i+1]), "\": must be ",
 			    "positive screen distance", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "VALUE", "INT_PAD", NULL);
 		    return TCL_ERROR;
 		}
 		slavePtr->iPadY = tmp * 2;
@@ -3229,6 +3255,7 @@ ConfigureSlaves(
 		    Tcl_AppendResult(interp, "bad row value \"",
 			    Tcl_GetString(objv[i+1]),
 			    "\": must be a non-negative integer", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "VALUE", "COLUMN", NULL);
 		    return TCL_ERROR;
 		}
 		if (SetSlaveRow(interp, slavePtr, tmp, -1) != TCL_OK) {
@@ -3241,6 +3268,7 @@ ConfigureSlaves(
 		    Tcl_AppendResult(interp, "bad rowspan value \"",
 			    Tcl_GetString(objv[i+1]),
 			    "\": must be a positive integer", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "VALUE", "SPAN", NULL);
 		    return TCL_ERROR;
 		}
 		if (SetSlaveRow(interp, slavePtr, -1, tmp) != TCL_OK) {
@@ -3307,6 +3335,7 @@ ConfigureSlaves(
 	    if (Tk_TopWinHierarchy(ancestor)) {
 		Tcl_AppendResult(interp, "can't put ", Tcl_GetString(objv[j]),
 			" inside ", Tk_PathName(masterPtr->tkwin), NULL);
+		Tcl_SetErrorCode(interp, "TK", "GEOMETRY", "HIERARCHY", NULL);
 		Unlink(slavePtr);
 		return TCL_ERROR;
 	    }
@@ -3320,6 +3349,7 @@ ConfigureSlaves(
 	    Tcl_AppendResult(interp, "can't put ", Tcl_GetString(objv[j]),
 		    " inside ", Tk_PathName(masterPtr->tkwin),
 		    ", would cause management loop.", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GEOMETRY", "LOOP", NULL);
 	    Unlink(slavePtr);
 	    return TCL_ERROR;
      	}
@@ -3398,6 +3428,7 @@ ConfigureSlaves(
 
 	if (masterPtr == NULL) {
 	    Tcl_AppendResult(interp, "can't use '^', cant find master", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GRID", "SHORTCUT_USAGE", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -3451,12 +3482,14 @@ ConfigureSlaves(
 	if (!match) {
 	    Tcl_AppendResult(interp, "can't find slave to extend with \"^\".",
 		    NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GRID", "SHORTCUT_USAGE", NULL);
 	    return TCL_ERROR;
 	}
     }
 
     if (masterPtr == NULL) {
 	Tcl_AppendResult(interp, "can't determine master window", NULL);
+	Tcl_SetErrorCode(interp, "TK", "GRID", "SHORTCUT_USAGE", NULL);
 	return TCL_ERROR;
     }
     SetGridSize(masterPtr);
@@ -3497,6 +3530,7 @@ StickyToString(
     char *result)		/* Where to put the result. */
 {
     int count = 0;
+
     if (flags&STICK_NORTH) {
     	result[count++] = 'n';
     }
diff --git a/generic/tkImage.c b/generic/tkImage.c
index 5fa3671..9cc8738 100644
--- a/generic/tkImage.c
+++ b/generic/tkImage.c
@@ -273,6 +273,7 @@ Tk_ImageObjCmd(
 	if (typePtr == NULL) {
 	    Tcl_AppendResult(interp, "image type \"", arg, "\" doesn't exist",
 		    NULL);
+	    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "IMAGE_TYPE", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -306,6 +307,7 @@ Tk_ImageObjCmd(
 	    if (topWin != NULL && winPtr->mainPtr->winPtr == topWin) {
 		Tcl_AppendResult(interp, "images may not be named the ",
 			"same as the main window", NULL);
+		Tcl_SetErrorCode(interp, "TK", "IMAGE", "SMASH_MAIN", NULL);
 		return TCL_ERROR;
 	    }
 	}
@@ -491,6 +493,7 @@ Tk_ImageObjCmd(
 
   alreadyDeleted:
     Tcl_AppendResult(interp, "image \"", arg, "\" doesn't exist", NULL);
+    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "IMAGE", NULL);
     return TCL_ERROR;
 }
 
@@ -631,6 +634,7 @@ Tk_GetImage(
   noSuchImage:
     if (interp) {
 	Tcl_AppendResult(interp, "image \"", name, "\" doesn't exist", NULL);
+	Tcl_SetErrorCode(interp, "TK", "LOOKUP", "IMAGE", NULL);
     }
     return NULL;
 }
diff --git a/generic/tkImgBmap.c b/generic/tkImgBmap.c
index 82374cb..a08bb8f 100644
--- a/generic/tkImgBmap.c
+++ b/generic/tkImgBmap.c
@@ -279,6 +279,8 @@ ImgBmapConfigureMaster(
 	if (masterPtr->data == NULL) {
 	    Tcl_SetResult(masterPtr->interp, "can't have mask without bitmap",
 		    TCL_STATIC);
+	    Tcl_SetErrorCode(masterPtr->interp, "TK", "IMAGE", "BITMAP",
+		    "NO_BITMAP", NULL);
 	    return TCL_ERROR;
 	}
 	masterPtr->maskData = TkGetBitmapData(masterPtr->interp,
@@ -293,6 +295,8 @@ ImgBmapConfigureMaster(
 	    masterPtr->maskData = NULL;
 	    Tcl_SetResult(masterPtr->interp,
 		    "bitmap and mask have different sizes", TCL_STATIC);
+	    Tcl_SetErrorCode(masterPtr->interp, "TK", "IMAGE", "BITMAP",
+		    "MASK_SIZE", NULL);
 	    return TCL_ERROR;
 	}
     }
@@ -492,6 +496,7 @@ TkGetBitmapData(
 	if ((interp != NULL) && Tcl_IsSafe(interp)) {
 	    Tcl_AppendResult(interp, "can't get bitmap data from a file in a",
 		    " safe interpreter", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "BITMAP", "SAFE", NULL);
 	    return NULL;
 	}
 	expandedFileName = Tcl_TranslateFileName(interp, fileName, &buffer);
@@ -595,6 +600,8 @@ TkGetBitmapData(
 	    if (interp != NULL) {
 		Tcl_AppendResult(interp, "format error in bitmap data; ",
 			"looks like it's an obsolete X10 bitmap file", NULL);
+		Tcl_SetErrorCode(interp, "TK", "IMAGE", "BITMAP", "OBSOLETE",
+			NULL);
 	    }
 	    goto errorCleanup;
 	}
@@ -637,6 +644,7 @@ TkGetBitmapData(
   error:
     if (interp != NULL) {
 	Tcl_SetResult(interp, "format error in bitmap data", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "BITMAP", "FORMAT", NULL);
     }
 
   errorCleanup:
@@ -1154,6 +1162,7 @@ ImgBmapPsImagemask(
 	Tcl_ResetResult(interp);
 	Tcl_AppendResult(interp, "unable to generate postscript for bitmaps "
 		"larger than 60000 pixels", NULL);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "BITMAP", "OUTSIZE", NULL);
 	return TCL_ERROR;
     }
 
diff --git a/generic/tkImgGIF.c b/generic/tkImgGIF.c
index 4cbf94d..62d364f 100644
--- a/generic/tkImgGIF.c
+++ b/generic/tkImgGIF.c
@@ -432,6 +432,8 @@ FileReadGIF(
 	if (i == (argc-1)) {
 	    Tcl_AppendResult(interp, "no value given for \"",
 		    Tcl_GetString(objv[i]), "\" option", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF", "OPT_VALUE",
+		    NULL);
 	    return TCL_ERROR;
 	}
 	if (Tcl_GetIntFromObj(interp, objv[++i], &index) != TCL_OK) {
@@ -446,11 +448,13 @@ FileReadGIF(
     if (!ReadGIFHeader(gifConfPtr, chan, &fileWidth, &fileHeight)) {
 	Tcl_AppendResult(interp, "couldn't read GIF header from file \"",
 		fileName, "\"", NULL);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF", "HEADER", NULL);
 	return TCL_ERROR;
     }
     if ((fileWidth <= 0) || (fileHeight <= 0)) {
 	Tcl_AppendResult(interp, "GIF image file \"", fileName,
 		"\" has dimension(s) <= 0", NULL);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF", "BOGUS_SIZE", NULL);
 	return TCL_ERROR;
     }
 
@@ -466,6 +470,8 @@ FileReadGIF(
     if (BitSet(buf[0], LOCALCOLORMAP)) {	/* Global Colormap */
 	if (!ReadColorMap(gifConfPtr, chan, bitPixel, colorMap)) {
 	    Tcl_AppendResult(interp, "error reading color map", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF", "COLOR_MAP",
+		    NULL);
 	    return TCL_ERROR;
 	}
     }
@@ -503,12 +509,15 @@ FileReadGIF(
 
 	    Tcl_AppendResult(interp,
 		    "premature end of image data for this index", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF", "PREMATURE_END",
+		    NULL);
 	    goto error;
 	}
 
 	switch (buf[0]) {
 	case GIF_TERMINATOR:
 	    Tcl_AppendResult(interp, "no image data for this index", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF", "NO_DATA", NULL);
 	    goto error;
 
 	case GIF_EXTENSION:
@@ -520,12 +529,16 @@ FileReadGIF(
 		Tcl_SetResult(interp,
 			"error reading extension function code in GIF image",
 			TCL_STATIC);
+		Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF", "BAD_EXT",
+			NULL);
 		goto error;
 	    }
 	    if (DoExtension(gifConfPtr, chan, buf[0],
 		    gifConfPtr->workingBuffer, &transparent) < 0) {
 		Tcl_SetResult(interp, "error reading extension in GIF image",
 			TCL_STATIC);
+		Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF", "BAD_EXT",
+			NULL);
 		goto error;
 	    }
 	    continue;
@@ -534,6 +547,8 @@ FileReadGIF(
 		Tcl_SetResult(interp,
 			"couldn't read left/top/width/height in GIF image",
 			TCL_STATIC);
+		Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF", "DIMENSIONS",
+			NULL);
 		goto error;
 	    }
 	    break;
@@ -562,6 +577,8 @@ FileReadGIF(
 	    if (BitSet(buf[8], LOCALCOLORMAP)) {
 		if (!ReadColorMap(gifConfPtr, chan, bitPixel, colorMap)) {
 		    Tcl_AppendResult(interp, "error reading color map", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF",
+			    "COLOR_MAP", NULL);
 		    goto error;
 		}
 	    }
@@ -609,6 +626,7 @@ FileReadGIF(
     if (BitSet(buf[8], LOCALCOLORMAP)) {
 	if (!ReadColorMap(gifConfPtr, chan, bitPixel, colorMap)) {
 	    Tcl_AppendResult(interp, "error reading color map", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF", "COLOR_MAP", NULL);
 	    goto error;
 	}
     }
@@ -1018,6 +1036,7 @@ ReadImage(
 
     if (initialCodeSize > MAX_LWZ_BITS) {
 	Tcl_SetResult(interp, "malformed image", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF", "MALFORMED", NULL);
 	return TCL_ERROR;
     }
 
@@ -1690,6 +1709,7 @@ CommonWriteGIF(
     SaveMap(&state, blockPtr);
     if (state.num >= MAXCOLORMAPSIZE) {
 	Tcl_AppendResult(interp, "too many colors", NULL);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "GIF", "COLORFUL", NULL);
 	return TCL_ERROR;
     }
     if (state.num<2) {
diff --git a/generic/tkImgPNG.c b/generic/tkImgPNG.c
index 8d6721e..96a17bd 100644
--- a/generic/tkImgPNG.c
+++ b/generic/tkImgPNG.c
@@ -335,6 +335,7 @@ InitPNGImage(
     if (Tcl_ZlibStreamInit(NULL, dir, TCL_ZLIB_FORMAT_ZLIB,
 	    TCL_ZLIB_COMPRESS_DEFAULT, NULL, &pngPtr->stream) != TCL_OK) {
 	Tcl_SetResult(interp, "zlib initialization failed", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "ZLIB_INIT", NULL);
 	if (objPtr) {
 	    Tcl_DecrRefCount(objPtr);
 	}
@@ -516,6 +517,7 @@ ReadBase64(
 
     if (destSz) {
 	Tcl_SetResult(interp, "Unexpected end of image data", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "EARLY_END", NULL);
 	return TCL_ERROR;
     }
 
@@ -558,6 +560,7 @@ ReadByteArray(
 
     if (pngPtr->strDataLen < destSz) {
 	Tcl_SetResult(interp, "Unexpected end of image data", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "EARLY_END", NULL);
 	return TCL_ERROR;
     }
 
@@ -625,7 +628,8 @@ ReadData(
 
 	if (blockSz < 0) {
 	    /* TODO: failure info... */
-	    Tcl_SetResult(interp, "Channel read failed", TCL_STATIC);
+	    Tcl_AppendResult(interp, "channel read failed: ",
+		    Tcl_PosixError(interp), NULL);
 	    return TCL_ERROR;
 	}
 
@@ -647,7 +651,8 @@ ReadData(
 	 */
 
 	if (destSz && Tcl_Eof(pngPtr->channel)) {
-	    Tcl_SetResult(interp, "Unexpected end of file ", TCL_STATIC);
+	    Tcl_SetResult(interp, "unexpected end of file", TCL_STATIC);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "EOF", NULL);
 	    return TCL_ERROR;
 	}
     }
@@ -733,6 +738,7 @@ CheckCRC(
 
     if (calculated != chunked) {
 	Tcl_SetResult(interp, "CRC check failed", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "CRC", NULL);
 	return TCL_ERROR;
     }
 
@@ -882,8 +888,9 @@ ReadChunkHeader(
 	temp = PNG_INT32(pc[0], pc[1], pc[2], pc[3]);
 
 	if (temp > INT_MAX) {
-	    Tcl_SetResult(interp, "Chunk size is out of supported range "
+	    Tcl_SetResult(interp, "chunk size is out of supported range "
 		    "on this architecture", TCL_STATIC);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "OUTSIZE", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -968,8 +975,10 @@ ReadChunkHeader(
 
 	    if (!(chunkType & PNG_CF_ANCILLARY)) {
 		Tcl_SetResult(interp,
-			"Encountered an unsupported criticial chunk type",
+			"encountered an unsupported criticial chunk type",
 			TCL_STATIC);
+		Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG",
+			"UNSUPPORTED_CRITICAL", NULL);
 		return TCL_ERROR;
 	    }
 
@@ -980,7 +989,9 @@ ReadChunkHeader(
 	    for (i=0 ; i<4 ; i++) {
 		if ((pc[i] < 65) || (pc[i] > 122) ||
 			((pc[i] > 90) && (pc[i] < 97))) {
-		    Tcl_SetResult(interp, "Invalid chunk type", TCL_STATIC);
+		    Tcl_SetResult(interp, "invalid chunk type", TCL_STATIC);
+		    Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG",
+			    "INVALID_CHUNK", NULL);
 		    return TCL_ERROR;
 		}
 	    }
@@ -1083,13 +1094,15 @@ CheckColor(
 	break;
 
     default:
-	Tcl_SetResult(interp, "Unknown Color Type field", TCL_STATIC);
+	Tcl_SetResult(interp, "unknown color type field", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "UNKNOWN_COLOR", NULL);
 	return TCL_ERROR;
     }
 
     if (TCL_ERROR == result) {
-	Tcl_SetResult(interp, "Bit depth is not allowed for given color type",
+	Tcl_SetResult(interp, "bit depth is not allowed for given color type",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_DEPTH", NULL);
 	return TCL_ERROR;
     }
 
@@ -1118,8 +1131,9 @@ CheckColor(
 
     if (pngPtr->block.width > INT_MAX / pngPtr->block.pixelSize) {
 	Tcl_SetResult(interp,
-		"Image pitch is out of supported range on this architecture",
+		"image pitch is out of supported range on this architecture",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "PITCH", NULL);
 	return TCL_ERROR;
     }
 
@@ -1131,8 +1145,9 @@ CheckColor(
      */
 
     if (pngPtr->block.height > INT_MAX / pngPtr->block.pitch) {
-	Tcl_SetResult(interp, "Image total size is out of supported range "
+	Tcl_SetResult(interp, "image total size is out of supported range "
 		"on this architecture", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "SIZE", NULL);
 	return TCL_ERROR;
     }
 
@@ -1161,6 +1176,7 @@ CheckColor(
     default:
 	Tcl_SetResult(interp, "internal error - unknown color type",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "UNKNOWN_COLOR", NULL);
 	return TCL_ERROR;
     }
 
@@ -1240,8 +1256,9 @@ ReadIHDR(
     }
 
     if (mismatch) {
-	Tcl_SetResult(interp, "Data stream does not have a PNG signature",
+	Tcl_SetResult(interp, "data stream does not have a PNG signature",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "NO_SIG", NULL);
 	return TCL_ERROR;
     }
 
@@ -1257,12 +1274,14 @@ ReadIHDR(
      */
 
     if (chunkType != CHUNK_IHDR) {
-	Tcl_SetResult(interp, "Expected IHDR chunk type", TCL_STATIC);
+	Tcl_SetResult(interp, "expected IHDR chunk type", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "NO_IHDR", NULL);
 	return TCL_ERROR;
     }
 
     if (chunkSz != 13) {
-	Tcl_SetResult(interp, "Invalid IHDR chunk size", TCL_STATIC);
+	Tcl_SetResult(interp, "invalid IHDR chunk size", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_IHDR", NULL);
 	return TCL_ERROR;
     }
 
@@ -1282,8 +1301,9 @@ ReadIHDR(
 
     if (!width || !height || (width > INT_MAX) || (height > INT_MAX)) {
 	Tcl_SetResult(interp,
-		"Image dimensions are invalid or beyond architecture limits",
+		"image dimensions are invalid or beyond architecture limits",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "DIMENSIONS", NULL);
 	return TCL_ERROR;
     }
 
@@ -1326,7 +1346,8 @@ ReadIHDR(
     }
 
     if (PNG_COMPRESS_DEFLATE != pngPtr->compression) {
-	Tcl_SetResult(interp, "Unknown compression method", TCL_STATIC);
+	Tcl_SetResult(interp, "unknown compression method", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_COMPRESS", NULL);
 	return TCL_ERROR;
     }
 
@@ -1340,7 +1361,8 @@ ReadIHDR(
     }
 
     if (PNG_FILTMETH_STANDARD != pngPtr->filter) {
-	Tcl_SetResult(interp, "Unknown filter method", TCL_STATIC);
+	Tcl_SetResult(interp, "unknown filter method", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_FILTER", NULL);
 	return TCL_ERROR;
     }
 
@@ -1354,7 +1376,8 @@ ReadIHDR(
 	break;
 
     default:
-	Tcl_SetResult(interp, "Unknown interlace method", TCL_STATIC);
+	Tcl_SetResult(interp, "unknown interlace method", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_INTERLACE", NULL);
 	return TCL_ERROR;
     }
 
@@ -1399,6 +1422,8 @@ ReadPLTE(
     case PNG_COLOR_GRAYALPHA:
 	Tcl_SetResult(interp, "PLTE chunk type forbidden for grayscale",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "PLTE_UNEXPECTED",
+		NULL);
 	return TCL_ERROR;
 
     default:
@@ -1412,7 +1437,8 @@ ReadPLTE(
      */
 
     if (!chunkSz || (chunkSz > PNG_PLTE_MAXSZ) || (chunkSz % 3)) {
-	Tcl_SetResult(interp, "Invalid palette chunk size", TCL_STATIC);
+	Tcl_SetResult(interp, "invalid palette chunk size", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_PLTE", NULL);
 	return TCL_ERROR;
     }
 
@@ -1477,6 +1503,7 @@ ReadTRNS(
 	Tcl_SetResult(interp,
 		"tRNS chunk not allowed color types with a full alpha channel",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "INVALID_TRNS", NULL);
 	return TCL_ERROR;
     }
 
@@ -1486,7 +1513,8 @@ ReadTRNS(
      */
 
     if (chunkSz > PNG_TRNS_MAXSZ) {
-	Tcl_SetResult(interp, "Invalid tRNS chunk size", TCL_STATIC);
+	Tcl_SetResult(interp, "invalid tRNS chunk size", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_TRNS", NULL);
 	return TCL_ERROR;
     }
 
@@ -1516,8 +1544,9 @@ ReadTRNS(
 
 	if (chunkSz > pngPtr->paletteLen) {
 	    Tcl_SetResult(interp,
-		    "Size of tRNS chunk is too large for the palette",
+		    "size of tRNS chunk is too large for the palette",
 		    TCL_STATIC);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "TRNS_SIZE", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -1534,8 +1563,9 @@ ReadTRNS(
 
 	if (chunkSz != 2) {
 	    Tcl_SetResult(interp,
-		    "Invalid tRNS chunk size - must 2 bytes for grayscale",
+		    "invalid tRNS chunk size - must 2 bytes for grayscale",
 		    TCL_STATIC);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_TRNS", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -1560,8 +1590,9 @@ ReadTRNS(
 
 	if (chunkSz != 6) {
 	    Tcl_SetResult(interp,
-		    "Invalid tRNS chunk size - must 6 bytes for RGB",
+		    "invalid tRNS chunk size - must 6 bytes for RGB",
 		    TCL_STATIC);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_TRNS", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -1742,7 +1773,8 @@ UnfilterLine(
 	}
 	break;
     default:
-	Tcl_SetResult(interp, "Invalid filter type", TCL_STATIC);
+	Tcl_SetResult(interp, "invalid filter type", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_FILTER", NULL);
 	return TCL_ERROR;
     }
 
@@ -2049,8 +2081,10 @@ ReadIDAT(
 	     */
 
 	    if (Tcl_ZlibStreamEof(pngPtr->stream)) {
-		Tcl_SetResult(interp, "Extra data after end of zlib stream",
+		Tcl_SetResult(interp, "extra data after end of zlib stream",
 			TCL_STATIC);
+		Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "EXTRA_DATA",
+			NULL);
 		return TCL_ERROR;
 	    }
 
@@ -2090,8 +2124,10 @@ ReadIDAT(
 	if (len2 == pngPtr->phaseSize) {
 	    if (pngPtr->phase > 7) {
 		Tcl_SetResult(interp,
-			"Extra data after final scan line of final phase",
+			"extra data after final scan line of final phase",
 			TCL_STATIC);
+		Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "EXTRA_DATA",
+			NULL);
 		return TCL_ERROR;
 	    }
 
@@ -2136,6 +2172,7 @@ ReadIDAT(
     if (chunkSz != 0) {
 	Tcl_AppendResult(interp,
 		"compressed data after stream finalize in PNG data", NULL);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "EXTRA_DATA", NULL);
 	return TCL_ERROR;
     }
 
@@ -2274,6 +2311,8 @@ ParseFormat(
 		Tcl_SetResult(interp,
 			"-alpha value must be between 0.0 and 1.0",
 			TCL_STATIC);
+		Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_ALPHA",
+			NULL);
 		return TCL_ERROR;
 	    }
 	    break;
@@ -2365,6 +2404,7 @@ DecodePNG(
     } else if (PNG_COLOR_PLTE == pngPtr->colorType) {
 	Tcl_SetResult(interp, "PLTE chunk required for indexed color",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "NEED_PLTE", NULL);
 	return TCL_ERROR;
     }
 
@@ -2400,8 +2440,9 @@ DecodePNG(
      */
 
     if (CHUNK_IDAT != chunkType) {
-	Tcl_SetResult(interp, "At least one IDAT chunk is required",
+	Tcl_SetResult(interp, "at least one IDAT chunk is required",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "NEED_IDAT", NULL);
 	return TCL_ERROR;
     }
 
@@ -2423,8 +2464,9 @@ DecodePNG(
 
     if (pngPtr->block.width > ((INT_MAX - 1) / (pngPtr->numChannels * 2))) {
 	Tcl_SetResult(interp,
-		"Line size is out of supported range on this architecture",
+		"line size is out of supported range on this architecture",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "LINE_SIZE", NULL);
 	return TCL_ERROR;
     }
 
@@ -2449,7 +2491,8 @@ DecodePNG(
 
     pngPtr->block.pixelPtr = attemptckalloc(pngPtr->blockLen);
     if (!pngPtr->block.pixelPtr) {
-	Tcl_SetResult(interp, "Memory allocation failed", TCL_STATIC);
+	Tcl_SetResult(interp, "memory allocation failed", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "MALLOC", NULL);
 	return TCL_ERROR;
     }
 
@@ -2500,6 +2543,7 @@ DecodePNG(
 
     if (!Tcl_ZlibStreamEof(pngPtr->stream)) {
 	Tcl_AppendResult(interp, "unfinalized data stream in PNG data", NULL);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "EXTRA_DATA", NULL);
 	return TCL_ERROR;
     }
 
@@ -2525,6 +2569,7 @@ DecodePNG(
     if (chunkSz) {
 	Tcl_SetResult(interp, "IEND chunk contents must be empty",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_IEND", NULL);
 	return TCL_ERROR;
     }
 
@@ -2543,7 +2588,8 @@ DecodePNG(
 
 #if 0
     if (ReadData(interp, pngPtr, &c, 1, NULL) != TCL_ERROR) {
-	Tcl_SetResult(interp, "Extra data following IEND chunk", TCL_STATIC);
+	Tcl_SetResult(interp, "extra data following IEND chunk", TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "BAD_IEND", NULL);
 	return TCL_ERROR;
     }
 #endif
@@ -2796,23 +2842,24 @@ WriteData(
 
 	if (objSz > INT_MAX - srcSz) {
 	    Tcl_SetResult(interp,
-		    "Image too large to store completely in byte array",
+		    "image too large to store completely in byte array",
 		    TCL_STATIC);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "TOO_LARGE", NULL);
 	    return TCL_ERROR;
 	}
 
 	destPtr = Tcl_SetByteArrayLength(pngPtr->objDataPtr, objSz + srcSz);
 
 	if (!destPtr) {
-	    Tcl_SetResult(interp, "Memory allocation failed", TCL_STATIC);
+	    Tcl_SetResult(interp, "memory allocation failed", TCL_STATIC);
+	    Tcl_SetErrorCode(interp, "TK", "MALLOC", NULL);
 	    return TCL_ERROR;
 	}
 
 	memcpy(destPtr+objSz, srcPtr, srcSz);
     } else if (Tcl_Write(pngPtr->channel, (const char *) srcPtr, srcSz) < 0) {
-	/* TODO: reason */
-
-	Tcl_SetResult(interp, "Write to channel failed", TCL_STATIC);
+	Tcl_AppendResult(interp, "write to channel failed: ",
+		Tcl_PosixError(interp), NULL);
 	return TCL_ERROR;
     }
 
@@ -3128,6 +3175,7 @@ WriteIDAT(
 	if (Tcl_ZlibStreamPut(pngPtr->stream, pngPtr->thisLineObj,
 		flush) != TCL_OK) {
 	    Tcl_SetResult(interp, "deflate() returned error", TCL_STATIC);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "DEFLATE", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -3301,8 +3349,9 @@ EncodePNG(
 
     if ((blockPtr->width > (INT_MAX - 1) / (pngPtr->bytesPerPixel)) ||
 	    (blockPtr->height > INT_MAX / pngPtr->lineSize)) {
-	Tcl_SetResult(interp, "Image is too large to encode pixel data",
+	Tcl_SetResult(interp, "image is too large to encode pixel data",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "TOO_LARGE", NULL);
 	return TCL_ERROR;
     }
 
diff --git a/generic/tkImgPPM.c b/generic/tkImgPPM.c
index 527efa2..0378d16 100644
--- a/generic/tkImgPPM.c
+++ b/generic/tkImgPPM.c
@@ -149,11 +149,13 @@ FileReadPPM(
     if (type == 0) {
 	Tcl_AppendResult(interp, "couldn't read raw PPM header from file \"",
 		fileName, "\"", NULL);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PPM", "NO_HEADER", NULL);
 	return TCL_ERROR;
     }
     if ((fileWidth <= 0) || (fileHeight <= 0)) {
 	Tcl_AppendResult(interp, "PPM image file \"", fileName,
 		"\" has dimension(s) <= 0", NULL);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PPM", "DIMENSIONS", NULL);
 	return TCL_ERROR;
     }
     if ((maxIntensity <= 0) || (maxIntensity >= 256)) {
@@ -162,6 +164,7 @@ FileReadPPM(
 	sprintf(buffer, "%d", maxIntensity);
 	Tcl_AppendResult(interp, "PPM image file \"", fileName,
 		"\" has bad maximum intensity value ", buffer, NULL);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PPM", "INTENSITY", NULL);
 	return TCL_ERROR;
     }
 
@@ -484,11 +487,13 @@ StringReadPPM(
     if (type == 0) {
 	Tcl_AppendResult(interp, "couldn't read raw PPM header from string",
 		NULL);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PPM", "NO_HEADER", NULL);
 	return TCL_ERROR;
     }
     if ((fileWidth <= 0) || (fileHeight <= 0)) {
 	Tcl_AppendResult(interp, "PPM image data has dimension(s) <= 0",
 		NULL);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PPM", "DIMENSIONS", NULL);
 	return TCL_ERROR;
     }
     if ((maxIntensity <= 0) || (maxIntensity >= 256)) {
@@ -498,6 +503,7 @@ StringReadPPM(
 	Tcl_AppendResult(interp,
 		"PPM image data has bad maximum intensity value ", buffer,
 		NULL);
+	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PPM", "INTENSITY", NULL);
 	return TCL_ERROR;
     }
 
@@ -539,6 +545,7 @@ StringReadPPM(
 
 	if (block.pitch*height > dataSize) {
 	    Tcl_AppendResult(interp, "truncated PPM data", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "PPM", "TRUNCATED", NULL);
 	    return TCL_ERROR;
 	}
 	block.pixelPtr = dataBuffer + srcX * block.pixelSize;
@@ -573,6 +580,7 @@ StringReadPPM(
 	if (dataSize < nBytes) {
 	    ckfree(pixelPtr);
 	    Tcl_AppendResult(interp, "truncated PPM data", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "PPM", "TRUNCATED", NULL);
 	    return TCL_ERROR;
 	}
 	for (p=pixelPtr,count=nBytes ; count>0 ; count--,p++,dataBuffer++) {
diff --git a/generic/tkImgPhoto.c b/generic/tkImgPhoto.c
index 5b172f1..d1e8524 100644
--- a/generic/tkImgPhoto.c
+++ b/generic/tkImgPhoto.c
@@ -565,6 +565,7 @@ ImgPhotoCmd(
 	    Tcl_AppendResult(interp, "image \"",
 		    Tcl_GetString(options.name), "\" doesn't",
 		    " exist or is not a photo image", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "PHOTO", NULL);
 	    return TCL_ERROR;
 	}
 	Tk_PhotoGetImage(srcHandle, &block);
@@ -573,6 +574,7 @@ ImgPhotoCmd(
 		|| (options.fromY2 > block.height)) {
 	    Tcl_AppendResult(interp, "coordinates for -from option extend ",
 		    "outside source image", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PHOTO", "BAD_FROM", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -626,6 +628,7 @@ ImgPhotoCmd(
 		    options.toY2) != TCL_OK) {
 		Tcl_ResetResult(interp);
 		Tcl_AppendResult(interp, TK_PHOTO_ALLOC_FAILURE_MESSAGE, NULL);
+		Tcl_SetErrorCode(interp, "TK", "MALLOC", NULL);
 		return TCL_ERROR;
 	    }
 	}
@@ -674,6 +677,7 @@ ImgPhotoCmd(
 		|| (options.fromY2 > masterPtr->height)) {
 	    Tcl_AppendResult(interp, "coordinates for -from option extend ",
 		    "outside image", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PHOTO", "BAD_FROM", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -722,6 +726,8 @@ ImgPhotoCmd(
 		Tcl_AppendResult(interp, "image string format \"",
 			Tcl_GetString(options.format), "\" is ",
 			(matched ? "not supported" : "unknown"), NULL);
+		Tcl_SetErrorCode(interp, "TK", "LOOKUP", "PHOTO_FORMAT",
+			NULL);
 		return TCL_ERROR;
 	    }
 	} else {
@@ -770,7 +776,7 @@ ImgPhotoCmd(
 	 * photo get command - first parse and check parameters.
 	 */
 
-	char string[TCL_INTEGER_SPACE * 3];
+	Tcl_Obj *channels[3];
 
 	if (objc != 4) {
 	    Tcl_WrongNumArgs(interp, 2, objv, "x y");
@@ -784,6 +790,7 @@ ImgPhotoCmd(
 		|| (y < 0) || (y >= masterPtr->height)) {
 	    Tcl_AppendResult(interp, Tcl_GetString(objv[0]), " get: ",
 		    "coordinates out of range", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PHOTO", "COORDINATES", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -792,9 +799,10 @@ ImgPhotoCmd(
 	 */
 
 	pixelPtr = masterPtr->pix32 + (y * masterPtr->width + x) * 4;
-	sprintf(string, "%d %d %d", pixelPtr[0], pixelPtr[1],
-		pixelPtr[2]);
-	Tcl_AppendResult(interp, string, NULL);
+	channels[0] = Tcl_NewIntObj(pixelPtr[0]);
+	channels[1] = Tcl_NewIntObj(pixelPtr[1]);
+	channels[2] = Tcl_NewIntObj(pixelPtr[2]);
+	Tcl_SetObjResult(interp, Tcl_NewListObj(3, channels));
 	return TCL_OK;
     }
 
@@ -878,6 +886,8 @@ ImgPhotoCmd(
 	    } else if (listObjc != dataWidth) {
 		Tcl_AppendResult(interp, "all elements of color list must",
 			" have the same number of elements", NULL);
+		Tcl_SetErrorCode(interp, "TK", "PHOTO", "NON_RECTANGULAR",
+			NULL);
 		break;
 	    }
 
@@ -922,6 +932,7 @@ ImgPhotoCmd(
 			colorString, &color)) {
 		    Tcl_AppendResult(interp, "can't parse color \"",
 			    colorString, "\"", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "VALUE", "COLOR", NULL);
 		    break;
 		}
 		*pixelPtr++ = color.red >> 8;
@@ -994,6 +1005,7 @@ ImgPhotoCmd(
 	if (Tcl_IsSafe(interp)) {
 	    Tcl_AppendResult(interp, "can't get image from a file in a",
 		    " safe interpreter", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PHOTO", "SAFE", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -1033,6 +1045,7 @@ ImgPhotoCmd(
 		|| (options.fromY2 > imageHeight)) {
 	    Tcl_AppendResult(interp, "coordinates for -from option extend ",
 		    "outside source image", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PHOTO", "BAD_FROM", NULL);
 	    Tcl_Close(NULL, chan);
 	    return TCL_ERROR;
 	}
@@ -1053,6 +1066,7 @@ ImgPhotoCmd(
 		    options.toY + height) != TCL_OK) {
 		Tcl_ResetResult(interp);
 		Tcl_AppendResult(interp, TK_PHOTO_ALLOC_FAILURE_MESSAGE, NULL);
+		Tcl_SetErrorCode(interp, "TK", "MALLOC", NULL);
 		return TCL_ERROR;
 	    }
 	}
@@ -1145,6 +1159,7 @@ ImgPhotoCmd(
 		    || (y < 0) || (y >= masterPtr->height)) {
 		Tcl_AppendResult(interp, Tcl_GetString(objv[0]),
 			" transparency get: coordinates out of range", NULL);
+		Tcl_SetErrorCode(interp, "TK", "PHOTO", "COORDINATES", NULL);
 		return TCL_ERROR;
 	    }
 
@@ -1182,6 +1197,7 @@ ImgPhotoCmd(
 		|| (y < 0) || (y >= masterPtr->height)) {
 		Tcl_AppendResult(interp, Tcl_GetString(objv[0]),
 			" transparency set: coordinates out of range", NULL);
+		Tcl_SetErrorCode(interp, "TK", "PHOTO", "COORDINATES", NULL);
 		return TCL_ERROR;
 	    }
 
@@ -1246,6 +1262,7 @@ ImgPhotoCmd(
 	if (Tcl_IsSafe(interp)) {
 	    Tcl_AppendResult(interp, "can't write image to a file in a",
 		    " safe interpreter", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PHOTO", "SAFE", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -1272,6 +1289,7 @@ ImgPhotoCmd(
 		|| (options.fromY2 > masterPtr->height)) {
 	    Tcl_AppendResult(interp, "coordinates for -from option extend ",
 		    "outside image", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PHOTO", "BAD_FROM", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -1343,14 +1361,12 @@ ImgPhotoCmd(
 	    } else if (!matched) {
 		Tcl_AppendResult(interp, "image file format \"",
 			fmtString, "\" is unknown", NULL);
-		Tcl_SetErrorCode(interp, "TK", "LOOKUP", "PHOTO_FORMAT",
-			fmtString, NULL);
 	    } else {
 		Tcl_AppendResult(interp, "image file format \"",
 			fmtString, "\" has no file writing capability", NULL);
-		Tcl_SetErrorCode(interp, "TK", "LOOKUP", "PHOTO_FORMAT",
-			fmtString, NULL);
 	    }
+	    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "PHOTO_FORMAT",
+		    fmtString, NULL);
 	    return TCL_ERROR;
 	}
 
@@ -1502,6 +1518,7 @@ ParseSubcommandOptions(
 		}
 		bit <<= 1;
 	    }
+	    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "PHOTO_OPTION", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -1525,6 +1542,8 @@ ParseSubcommandOptions(
 	    } else {
 		Tcl_AppendResult(interp, "the \"-background\" option ",
 			"requires a value", NULL);
+		Tcl_SetErrorCode(interp, "TK", "PHOTO", "MISSING_VALUE",
+			NULL);
 		return TCL_ERROR;
 	    }
 	} else if (bit == OPT_FORMAT) {
@@ -1539,6 +1558,8 @@ ParseSubcommandOptions(
 	    } else {
 		Tcl_AppendResult(interp, "the \"-format\" option ",
 			"requires a value", NULL);
+		Tcl_SetErrorCode(interp, "TK", "PHOTO", "MISSING_VALUE",
+			NULL);
 		return TCL_ERROR;
 	    }
 	} else if (bit == OPT_COMPOSITE) {
@@ -1567,6 +1588,8 @@ ParseSubcommandOptions(
 	    } else {
 		Tcl_AppendResult(interp, "the \"-compositingrule\" option ",
 			"requires a value", NULL);
+		Tcl_SetErrorCode(interp, "TK", "PHOTO", "MISSING_VALUE",
+			NULL);
 		return TCL_ERROR;
 	    }
 	} else if ((bit != OPT_SHRINK) && (bit != OPT_GRAYSCALE)) {
@@ -1594,6 +1617,8 @@ ParseSubcommandOptions(
 		Tcl_AppendResult(interp, "the \"", option, "\" option ",
 			 "requires one ", maxValues == 2? "or two": "to four",
 			 " integer values", NULL);
+		Tcl_SetErrorCode(interp, "TK", "PHOTO", "MISSING_VALUE",
+			NULL);
 		return TCL_ERROR;
 	    }
 	    *optIndexPtr = (index += numValues);
@@ -1620,6 +1645,7 @@ ParseSubcommandOptions(
 			&& ((values[2] < 0) || (values[3] < 0)))) {
 		    Tcl_AppendResult(interp, "value(s) for the -from",
 			    " option must be non-negative", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "PHOTO", "BAD_FROM", NULL);
 		    return TCL_ERROR;
 		}
 		if (numValues <= 2) {
@@ -1643,6 +1669,7 @@ ParseSubcommandOptions(
 			&& ((values[2] < 0) || (values[3] < 0)))) {
 		    Tcl_AppendResult(interp, "value(s) for the -to",
 			    " option must be non-negative", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "PHOTO", "BAD_TO", NULL);
 		    return TCL_ERROR;
 		}
 		if (numValues <= 2) {
@@ -1661,6 +1688,7 @@ ParseSubcommandOptions(
 		if ((values[0] <= 0) || (values[1] <= 0)) {
 		    Tcl_AppendResult(interp, "value(s) for the -zoom",
 			    " option must be positive", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "PHOTO", "BAD_ZOOM", NULL);
 		    return TCL_ERROR;
 		}
 		optPtr->zoomX = values[0];
@@ -1732,6 +1760,8 @@ ImgPhotoConfigureMaster(
 		    ckfree(args);
 		    Tcl_AppendResult(interp,
 			    "value for \"-data\" missing", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "PHOTO", "MISSING_VALUE",
+			    NULL);
 		    return TCL_ERROR;
 		}
 	    } else if ((args[j][1] == 'f') &&
@@ -1743,6 +1773,8 @@ ImgPhotoConfigureMaster(
 		    ckfree(args);
 		    Tcl_AppendResult(interp,
 			    "value for \"-format\" missing", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "PHOTO", "MISSING_VALUE",
+			    NULL);
 		    return TCL_ERROR;
 		}
 	    }
@@ -1834,6 +1866,7 @@ ImgPhotoConfigureMaster(
 	    masterPtr->height) != TCL_OK) {
 	Tcl_ResetResult(interp);
 	Tcl_AppendResult(interp, TK_PHOTO_ALLOC_FAILURE_MESSAGE, NULL);
+	Tcl_SetErrorCode(interp, "TK", "MALLOC", NULL);
 	goto errorExit;
     }
 
@@ -1853,6 +1886,7 @@ ImgPhotoConfigureMaster(
 	    Tcl_ResetResult(interp);
 	    Tcl_AppendResult(interp,
 		    "can't get image from a file in a safe interpreter", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PHOTO", "SAFE", NULL);
 	    goto errorExit;
 	}
 
@@ -1878,6 +1912,7 @@ ImgPhotoConfigureMaster(
 	    Tcl_Close(NULL, chan);
 	    Tcl_ResetResult(interp);
 	    Tcl_AppendResult(interp, TK_PHOTO_ALLOC_FAILURE_MESSAGE, NULL);
+	    Tcl_SetErrorCode(interp, "TK", "MALLOC", NULL);
 	    goto errorExit;
 	}
 	tempformat = masterPtr->format;
@@ -1908,6 +1943,7 @@ ImgPhotoConfigureMaster(
 	if (ImgPhotoSetSize(masterPtr, imageWidth, imageHeight) != TCL_OK) {
 	    Tcl_ResetResult(interp);
 	    Tcl_AppendResult(interp, TK_PHOTO_ALLOC_FAILURE_MESSAGE, NULL);
+	    Tcl_SetErrorCode(interp, "TK", "MALLOC", NULL);
 	    goto errorExit;
 	}
 	tempformat = masterPtr->format;
@@ -2353,6 +2389,8 @@ MatchFileFormat(
 	    if (formatPtr->fileMatchProc == NULL) {
 		Tcl_AppendResult(interp, "-file option isn't supported for ",
 			formatString, " images", NULL);
+		Tcl_SetErrorCode(interp, "TK", "PHOTO", "NOT_FILE_FORMAT",
+			NULL);
 		return TCL_ERROR;
 	    }
 	}
@@ -2384,6 +2422,8 @@ MatchFileFormat(
 		if (formatPtr->fileMatchProc == NULL) {
 		    Tcl_AppendResult(interp, "-file option isn't supported",
 			    " for ", formatString, " images", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "PHOTO", "NOT_FILE_FORMAT",
+			    NULL);
 		    return TCL_ERROR;
 		}
 	    }
@@ -2407,10 +2447,13 @@ MatchFileFormat(
 	if ((formatObj != NULL) && !matched) {
 	    Tcl_AppendResult(interp, "image file format \"", formatString,
 		    "\" is not supported", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "PHOTO_FORMAT", NULL);
 	} else {
 	    Tcl_AppendResult(interp,
 		    "couldn't recognize data in image file \"", fileName, "\"",
 		    NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PHOTO", "UNRECOGNIZED_DATA",
+		    NULL);
 	}
 	return TCL_ERROR;
     }
@@ -2482,6 +2525,8 @@ MatchStringFormat(
 	    if (formatPtr->stringMatchProc == NULL) {
 		Tcl_AppendResult(interp, "-data option isn't supported for ",
 			formatString, " images", NULL);
+		Tcl_SetErrorCode(interp, "TK", "PHOTO", "NOT_DATA_FORMAT",
+			NULL);
 		return TCL_ERROR;
 	    }
 	}
@@ -2506,6 +2551,8 @@ MatchStringFormat(
 		if (formatPtr->stringMatchProc == NULL) {
 		    Tcl_AppendResult(interp, "-data option isn't supported",
 			    " for ", formatString, " images", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "PHOTO", "NOT_DATA_FORMAT",
+			    NULL);
 		    return TCL_ERROR;
 		}
 	    }
@@ -2523,8 +2570,11 @@ MatchStringFormat(
 	if ((formatObj != NULL) && !matched) {
 	    Tcl_AppendResult(interp, "image format \"", formatString,
 		    "\" is not supported", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "PHOTO_FORMAT", NULL);
 	} else {
 	    Tcl_AppendResult(interp, "couldn't recognize image data", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PHOTO", "UNRECOGNIZED_DATA",
+		    NULL);
 	}
 	return TCL_ERROR;
     }
@@ -2643,6 +2693,7 @@ Tk_PhotoPutBlock(
 	    if (interp != NULL) {
 		Tcl_ResetResult(interp);
 		Tcl_AppendResult(interp, TK_PHOTO_ALLOC_FAILURE_MESSAGE, NULL);
+		Tcl_SetErrorCode(interp, "TK", "MALLOC", NULL);
 	    }
 	    return TCL_ERROR;
 	}
@@ -3039,6 +3090,7 @@ Tk_PhotoPutZoomedBlock(
 	    if (interp != NULL) {
 		Tcl_ResetResult(interp);
 		Tcl_AppendResult(interp, TK_PHOTO_ALLOC_FAILURE_MESSAGE, NULL);
+		Tcl_SetErrorCode(interp, "TK", "MALLOC", NULL);
 	    }
 	    return TCL_ERROR;
 	}
@@ -3437,6 +3489,7 @@ Tk_PhotoExpand(
 	    if (interp != NULL) {
 		Tcl_ResetResult(interp);
 		Tcl_AppendResult(interp, TK_PHOTO_ALLOC_FAILURE_MESSAGE, NULL);
+		Tcl_SetErrorCode(interp, "TK", "MALLOC", NULL);
 	    }
 	    return TCL_ERROR;
 	}
@@ -3511,6 +3564,7 @@ Tk_PhotoSetSize(
 	if (interp != NULL) {
 	    Tcl_ResetResult(interp);
 	    Tcl_AppendResult(interp, TK_PHOTO_ALLOC_FAILURE_MESSAGE, NULL);
+	    Tcl_SetErrorCode(interp, "TK", "MALLOC", NULL);
 	}
 	return TCL_ERROR;
     }
diff --git a/generic/tkListbox.c b/generic/tkListbox.c
index 7faa44b..e8817af 100644
--- a/generic/tkListbox.c
+++ b/generic/tkListbox.c
@@ -168,6 +168,13 @@ typedef struct {
 } Listbox;
 
 /*
+ * How to encode the keys for the hash tables used to store what items are
+ * selected and what the attributes are.
+ */
+
+#define KEY(i)		((char *) INT2PTR(i))
+
+/*
  * ItemAttr structures are used to store item configuration information for
  * the items in a listbox
  */
@@ -437,8 +444,8 @@ static void		MigrateHashEntries(Tcl_HashTable *table,
 static const Tk_ClassProcs listboxClass = {
     sizeof(Tk_ClassProcs),	/* size */
     ListboxWorldChanged,	/* worldChangedProc */
-    NULL,					/* createProc */
-    NULL					/* modalProc */
+    NULL,			/* createProc */
+    NULL			/* modalProc */
 };
 
 /*
@@ -480,8 +487,7 @@ Tk_ListboxObjCmd(
 	return TCL_ERROR;
     }
 
-    optionTables = (ListboxOptionTables *)
-	Tcl_GetAssocData(interp, "ListboxOptionTables", NULL);
+    optionTables = Tcl_GetAssocData(interp, "ListboxOptionTables", NULL);
     if (optionTables == NULL) {
 	/*
 	 * We haven't created the option tables for this widget class yet. Do
@@ -515,7 +521,7 @@ Tk_ListboxObjCmd(
      */
 
     listPtr			 = ckalloc(sizeof(Listbox));
-    memset(listPtr, 0, (sizeof(Listbox)));
+    memset(listPtr, 0, sizeof(Listbox));
 
     listPtr->tkwin		 = tkwin;
     listPtr->display		 = Tk_Display(tkwin);
@@ -597,6 +603,7 @@ ListboxWidgetObjCmd(
     register Listbox *listPtr = clientData;
     int cmdIndex, index;
     int result = TCL_OK;
+    Tcl_Obj *objPtr;
 
     if (objc < 2) {
 	Tcl_WrongNumArgs(interp, 1, objv, "option ?arg ...?");
@@ -661,9 +668,7 @@ ListboxWidgetObjCmd(
 	result = ListboxBboxSubCmd(interp, listPtr, index);
 	break;
 
-    case COMMAND_CGET: {
-	Tcl_Obj *objPtr;
-
+    case COMMAND_CGET:
 	if (objc != 3) {
 	    Tcl_WrongNumArgs(interp, 2, objv, "option");
 	    result = TCL_ERROR;
@@ -679,11 +684,8 @@ ListboxWidgetObjCmd(
 	Tcl_SetObjResult(interp, objPtr);
 	result = TCL_OK;
 	break;
-    }
-
-    case COMMAND_CONFIGURE: {
-	Tcl_Obj *objPtr;
 
+    case COMMAND_CONFIGURE:
 	if (objc <= 3) {
 	    objPtr = Tk_GetOptionInfo(interp, (char *) listPtr,
 		    listPtr->optionTable,
@@ -698,10 +700,8 @@ ListboxWidgetObjCmd(
 	    result = ConfigureListbox(interp, listPtr, objc-2, objv+2, 0);
 	}
 	break;
-    }
 
     case COMMAND_CURSELECTION: {
-	char indexStringRep[TCL_INTEGER_SPACE];
 	int i;
 
 	if (objc != 2) {
@@ -718,12 +718,13 @@ ListboxWidgetObjCmd(
 	 * selected.
 	 */
 
+	objPtr = Tcl_NewObj();
 	for (i = 0; i < listPtr->nElements; i++) {
-	    if (Tcl_FindHashEntry(listPtr->selection, (char *) INT2PTR(i))) {
-		sprintf(indexStringRep, "%d", i);
-		Tcl_AppendElement(interp, indexStringRep);
+	    if (Tcl_FindHashEntry(listPtr->selection, KEY(i))) {
+		Tcl_ListObjAppendElement(NULL, objPtr, Tcl_NewIntObj(i));
 	    }
 	}
+	Tcl_SetObjResult(interp, objPtr);
 	result = TCL_OK;
 	break;
     }
@@ -857,7 +858,6 @@ ListboxWidgetObjCmd(
 	break;
 
     case COMMAND_ITEMCGET: {
-	Tcl_Obj *objPtr;
 	ItemAttr *attrPtr;
 
 	if (objc != 4) {
@@ -892,7 +892,6 @@ ListboxWidgetObjCmd(
     }
 
     case COMMAND_ITEMCONFIGURE: {
-	Tcl_Obj *objPtr;
 	ItemAttr *attrPtr;
 
 	if (objc < 3) {
@@ -922,10 +921,9 @@ ListboxWidgetObjCmd(
 	    if (objPtr == NULL) {
 		result = TCL_ERROR;
 		break;
-	    } else {
-		Tcl_SetObjResult(interp, objPtr);
-		result = TCL_OK;
 	    }
+	    Tcl_SetObjResult(interp, objPtr);
+	    result = TCL_OK;
 	} else {
 	    result = ConfigureListboxItem(interp, listPtr, attrPtr,
 		    objc-3, objv+3, index);
@@ -1007,7 +1005,7 @@ ListboxWidgetObjCmd(
 	}
 	diff = listPtr->topIndex - index;
 	if (diff > 0) {
-	    if (diff <= (listPtr->fullLines/3)) {
+	    if (diff <= listPtr->fullLines / 3) {
 		ChangeListboxView(listPtr, index);
 	    } else {
 		ChangeListboxView(listPtr, index - (listPtr->fullLines-1)/2);
@@ -1015,7 +1013,7 @@ ListboxWidgetObjCmd(
 	} else {
 	    diff = index - (listPtr->topIndex + listPtr->fullLines - 1);
 	    if (diff > 0) {
-		if (diff <= (listPtr->fullLines/3)) {
+		if (diff <= listPtr->fullLines / 3) {
 		    ChangeListboxView(listPtr, listPtr->topIndex + diff);
 		} else {
 		    ChangeListboxView(listPtr, index-(listPtr->fullLines-1)/2);
@@ -1090,7 +1088,7 @@ ListboxBboxSubCmd(
      */
 
     if ((listPtr->topIndex <= index) && (index < lastVisibleIndex)) {
-	Tcl_Obj *el;
+	Tcl_Obj *el, *results[4];
 	const char *stringRep;
 	int pixelWidth, stringLen, x, y, result;
 	Tk_FontMetrics fm;
@@ -1111,8 +1109,11 @@ ListboxBboxSubCmd(
 	x = listPtr->inset + listPtr->selBorderWidth - listPtr->xOffset;
 	y = ((index - listPtr->topIndex)*listPtr->lineHeight)
 		+ listPtr->inset + listPtr->selBorderWidth;
-	Tcl_SetObjResult(interp, Tcl_ObjPrintf("%d %d %d %d",
-		x, y, pixelWidth, fm.linespace));
+	results[0] = Tcl_NewIntObj(x);
+	results[1] = Tcl_NewIntObj(y);
+	results[2] = Tcl_NewIntObj(pixelWidth);
+	results[3] = Tcl_NewIntObj(fm.linespace);
+	Tcl_SetObjResult(interp, Tcl_NewListObj(4, results));
     }
     return TCL_OK;
 }
@@ -1197,9 +1198,8 @@ ListboxSelectionSubCmd(
 	    Tcl_WrongNumArgs(interp, 3, objv, "index");
 	    return TCL_ERROR;
 	}
-	Tcl_SetObjResult(interp,
-		Tcl_NewBooleanObj((Tcl_FindHashEntry(listPtr->selection,
-			(char *) INT2PTR(first)) != NULL)));
+	Tcl_SetObjResult(interp, Tcl_NewBooleanObj(
+		Tcl_FindHashEntry(listPtr->selection, KEY(first)) != NULL));
 	result = TCL_OK;
 	break;
     case SELECTION_SET:
@@ -1232,43 +1232,45 @@ ListboxXviewSubCmd(
     int objc,			/* Number of arguments in the objv array */
     Tcl_Obj *const objv[])	/* Array of arguments to the procedure */
 {
-
-    int index, count, type, windowWidth, windowUnits;
+    int index, count, windowWidth, windowUnits;
     int offset = 0;		/* Initialized to stop gcc warnings. */
     double fraction;
 
     windowWidth = Tk_Width(listPtr->tkwin)
 	    - 2*(listPtr->inset + listPtr->selBorderWidth);
     if (objc == 2) {
+	Tcl_Obj *results[2];
+
 	if (listPtr->maxWidth == 0) {
-	    Tcl_SetResult(interp, "0.0 1.0", TCL_STATIC);
+	    results[0] = Tcl_NewDoubleObj(0.0);
+	    results[1] = Tcl_NewDoubleObj(1.0);
 	} else {
 	    double fraction2;
 
-	    fraction = listPtr->xOffset/((double) listPtr->maxWidth);
+	    fraction = listPtr->xOffset / (double) listPtr->maxWidth;
 	    fraction2 = (listPtr->xOffset + windowWidth)
-		    / ((double) listPtr->maxWidth);
+		    / (double) listPtr->maxWidth;
 	    if (fraction2 > 1.0) {
 		fraction2 = 1.0;
 	    }
-	    Tcl_SetObjResult(interp, Tcl_ObjPrintf("%g %g",
-		    fraction, fraction2));
+	    results[0] = Tcl_NewDoubleObj(fraction);
+	    results[1] = Tcl_NewDoubleObj(fraction2);
 	}
+	Tcl_SetObjResult(interp, Tcl_NewListObj(2, results));
     } else if (objc == 3) {
 	if (Tcl_GetIntFromObj(interp, objv[2], &index) != TCL_OK) {
 	    return TCL_ERROR;
 	}
 	ChangeListboxOffset(listPtr, index*listPtr->xScrollUnit);
     } else {
-	type = Tk_GetScrollInfoObj(interp, objc, objv, &fraction, &count);
-	switch (type) {
+	switch (Tk_GetScrollInfoObj(interp, objc, objv, &fraction, &count)) {
 	case TK_SCROLL_ERROR:
 	    return TCL_ERROR;
 	case TK_SCROLL_MOVETO:
 	    offset = (int) (fraction*listPtr->maxWidth + 0.5);
 	    break;
 	case TK_SCROLL_PAGES:
-	    windowUnits = windowWidth/listPtr->xScrollUnit;
+	    windowUnits = windowWidth / listPtr->xScrollUnit;
 	    if (windowUnits > 2) {
 		offset = listPtr->xOffset
 			+ count*listPtr->xScrollUnit*(windowUnits-2);
@@ -1308,12 +1310,15 @@ ListboxYviewSubCmd(
     int objc,			/* Number of arguments in the objv array */
     Tcl_Obj *const objv[])	/* Array of arguments to the procedure */
 {
-    int index, count, type;
+    int index, count;
     double fraction;
 
     if (objc == 2) {
+	Tcl_Obj *results[2];
+
 	if (listPtr->nElements == 0) {
-	    Tcl_SetResult(interp, "0.0 1.0", TCL_STATIC);
+	    results[0] = Tcl_NewDoubleObj(0.0);
+	    results[1] = Tcl_NewDoubleObj(1.0);
 	} else {
 	    double fraction2, numEls = (double) listPtr->nElements;
 
@@ -1322,17 +1327,17 @@ ListboxYviewSubCmd(
 	    if (fraction2 > 1.0) {
 		fraction2 = 1.0;
 	    }
-	    Tcl_SetObjResult(interp, Tcl_ObjPrintf("%g %g",
-		    fraction, fraction2));
+	    results[0] = Tcl_NewDoubleObj(fraction);
+	    results[1] = Tcl_NewDoubleObj(fraction2);
 	}
+	Tcl_SetObjResult(interp, Tcl_NewListObj(2, results));
     } else if (objc == 3) {
 	if (GetListboxIndex(interp, listPtr, objv[2], 0, &index) != TCL_OK) {
 	    return TCL_ERROR;
 	}
 	ChangeListboxView(listPtr, index);
     } else {
-	type = Tk_GetScrollInfoObj(interp, objc, objv, &fraction, &count);
-	switch (type) {
+	switch (Tk_GetScrollInfoObj(interp, objc, objv, &fraction, &count)) {
 	case TK_SCROLL_MOVETO:
 	    index = (int) (listPtr->nElements*fraction + 0.5);
 	    break;
@@ -1383,8 +1388,7 @@ ListboxGetItemAttributes(
     Tcl_HashEntry *entry;
     ItemAttr *attrs;
 
-    entry = Tcl_CreateHashEntry(listPtr->itemAttrTable,
-	    (char *) INT2PTR(index), &isNew);
+    entry = Tcl_CreateHashEntry(listPtr->itemAttrTable, KEY(index), &isNew);
     if (isNew) {
 	attrs = ckalloc(sizeof(ItemAttr));
 	attrs->border = NULL;
@@ -1910,7 +1914,7 @@ DisplayListbox(
 	 * special foreground/background colors.
 	 */
 
-	entry = Tcl_FindHashEntry(listPtr->itemAttrTable, (char *) INT2PTR(i));
+	entry = Tcl_FindHashEntry(listPtr->itemAttrTable, KEY(i));
 
 	/*
 	 * If the listbox is enabled, items may be drawn differently; they may
@@ -1919,7 +1923,7 @@ DisplayListbox(
 	 */
 
 	if (listPtr->state & STATE_NORMAL) {
-	    if (Tcl_FindHashEntry(listPtr->selection, (char *) INT2PTR(i))) {
+	    if (Tcl_FindHashEntry(listPtr->selection, KEY(i))) {
 		/*
 		 * Selected items are drawn differently.
 		 */
@@ -2001,8 +2005,7 @@ DisplayListbox(
 		}
 		/* Draw bottom bevel */
 		if (i + 1 == listPtr->nElements ||
-			Tcl_FindHashEntry(listPtr->selection,
-				(char *) INT2PTR(i + 1)) == NULL ) {
+			!Tcl_FindHashEntry(listPtr->selection, KEY(i + 1))) {
 		    Tk_3DHorizontalBevel(tkwin, pixmap, selectedBg, x-left,
 			    y + listPtr->lineHeight - listPtr->selBorderWidth,
 			    width+left+right, listPtr->selBorderWidth, 0, 0, 0,
@@ -2238,7 +2241,7 @@ ListboxComputeGeometry(
     width = listPtr->width;
     if (width <= 0) {
 	width = (listPtr->maxWidth + listPtr->xScrollUnit - 1)
-		/listPtr->xScrollUnit;
+		/ listPtr->xScrollUnit;
 	if (width < 1) {
 	    width = 1;
 	}
@@ -2439,13 +2442,13 @@ ListboxDeleteSubCmd(
 	 * Remove selection information.
 	 */
 
-	entry = Tcl_FindHashEntry(listPtr->selection, (char *) INT2PTR(i));
+	entry = Tcl_FindHashEntry(listPtr->selection, KEY(i));
 	if (entry != NULL) {
 	    listPtr->numSelected--;
 	    Tcl_DeleteHashEntry(entry);
 	}
 
-	entry = Tcl_FindHashEntry(listPtr->itemAttrTable, (char *) INT2PTR(i));
+	entry = Tcl_FindHashEntry(listPtr->itemAttrTable, KEY(i));
 	if (entry != NULL) {
 	    ckfree(Tcl_GetHashValue(entry));
 	    Tcl_DeleteHashEntry(entry);
@@ -2903,7 +2906,7 @@ ListboxScanTo(
      */
 
     newTopIndex = listPtr->scanMarkYIndex
-	    - (10*(y - listPtr->scanMarkY))/listPtr->lineHeight;
+	    - (10*(y - listPtr->scanMarkY)) / listPtr->lineHeight;
     if (newTopIndex > maxIndex) {
 	newTopIndex = listPtr->scanMarkYIndex = maxIndex;
 	listPtr->scanMarkY = y;
@@ -2955,7 +2958,7 @@ NearestListboxElement(
 {
     int index;
 
-    index = (y - listPtr->inset)/listPtr->lineHeight;
+    index = (y - listPtr->inset) / listPtr->lineHeight;
     if (index >= (listPtr->fullLines + listPtr->partialLine)) {
 	index = listPtr->fullLines + listPtr->partialLine - 1;
     }
@@ -3026,7 +3029,7 @@ ListboxSelect(
      */
 
     for (i = first; i <= last; i++) {
-	entry = Tcl_FindHashEntry(listPtr->selection, (char *) INT2PTR(i));
+	entry = Tcl_FindHashEntry(listPtr->selection, KEY(i));
 	if (entry != NULL) {
 	    if (!select) {
 		Tcl_DeleteHashEntry(entry);
@@ -3037,8 +3040,8 @@ ListboxSelect(
 	    }
 	} else {
 	    if (select) {
-		entry = Tcl_CreateHashEntry(listPtr->selection,
-			(char *) INT2PTR(i), &isNew);
+		entry = Tcl_CreateHashEntry(listPtr->selection, KEY(i),
+			&isNew);
 		Tcl_SetHashValue(entry, NULL);
 		listPtr->numSelected++;
 		if (firstRedisplay < 0) {
@@ -3052,7 +3055,7 @@ ListboxSelect(
 	EventuallyRedrawRange(listPtr, first, last);
     }
     if ((oldCount == 0) && (listPtr->numSelected > 0)
-	    && (listPtr->exportSelection)) {
+	    && listPtr->exportSelection) {
 	Tk_OwnSelection(listPtr->tkwin, XA_PRIMARY,
 		ListboxLostSelection, listPtr);
     }
@@ -3109,7 +3112,7 @@ ListboxFetchSelection(
     needNewline = 0;
     Tcl_DStringInit(&selection);
     for (i = 0; i < listPtr->nElements; i++) {
-	entry = Tcl_FindHashEntry(listPtr->selection, (char *) INT2PTR(i));
+	entry = Tcl_FindHashEntry(listPtr->selection, KEY(i));
 	if (entry != NULL) {
 	    if (needNewline) {
 		Tcl_DStringAppend(&selection, "\n", 1);
@@ -3250,9 +3253,9 @@ ListboxUpdateVScrollbar(
 	first = 0.0;
 	last = 1.0;
     } else {
-	first = listPtr->topIndex / ((double) listPtr->nElements);
+	first = listPtr->topIndex / (double) listPtr->nElements;
 	last = (listPtr->topIndex + listPtr->fullLines)
-		/ ((double) listPtr->nElements);
+		/ (double) listPtr->nElements;
 	if (last > 1.0) {
 	    last = 1.0;
 	}
@@ -3309,15 +3312,15 @@ ListboxUpdateHScrollbar(
     if (listPtr->xScrollCmd == NULL) {
 	return;
     }
-    windowWidth = Tk_Width(listPtr->tkwin) - 2*(listPtr->inset
-	    + listPtr->selBorderWidth);
+
+    windowWidth = Tk_Width(listPtr->tkwin)
+	    - 2*(listPtr->inset + listPtr->selBorderWidth);
     if (listPtr->maxWidth == 0) {
 	first = 0;
 	last = 1.0;
     } else {
-	first = listPtr->xOffset/((double) listPtr->maxWidth);
-	last = (listPtr->xOffset + windowWidth)
-		/((double) listPtr->maxWidth);
+	first = listPtr->xOffset / (double) listPtr->maxWidth;
+	last = (listPtr->xOffset + windowWidth) / (double) listPtr->maxWidth;
 	if (last > 1.0) {
 	    last = 1.0;
 	}
@@ -3429,7 +3432,7 @@ ListboxListVarProc(
 	     * Clean up selection.
 	     */
 
-	    entry = Tcl_FindHashEntry(listPtr->selection, (char *) INT2PTR(i));
+	    entry = Tcl_FindHashEntry(listPtr->selection, KEY(i));
 	    if (entry != NULL) {
 		listPtr->numSelected--;
 		Tcl_DeleteHashEntry(entry);
@@ -3439,8 +3442,7 @@ ListboxListVarProc(
 	     * Clean up attributes.
 	     */
 
-	    entry = Tcl_FindHashEntry(listPtr->itemAttrTable,
-		    (char *) INT2PTR(i));
+	    entry = Tcl_FindHashEntry(listPtr->itemAttrTable, KEY(i));
 	    if (entry != NULL) {
 		ckfree(Tcl_GetHashValue(entry));
 		Tcl_DeleteHashEntry(entry);
@@ -3514,23 +3516,21 @@ MigrateHashEntries(
 
     if (offset > 0) {
 	for (i = last; i >= first; i--) {
-	    entry = Tcl_FindHashEntry(table, (char *) INT2PTR(i));
+	    entry = Tcl_FindHashEntry(table, KEY(i));
 	    if (entry != NULL) {
 		clientData = Tcl_GetHashValue(entry);
 		Tcl_DeleteHashEntry(entry);
-		entry = Tcl_CreateHashEntry(table,
-			(char *) INT2PTR(i + offset), &isNew);
+		entry = Tcl_CreateHashEntry(table, KEY(i + offset), &isNew);
 		Tcl_SetHashValue(entry, clientData);
 	    }
 	}
     } else {
 	for (i = first; i <= last; i++) {
-	    entry = Tcl_FindHashEntry(table, (char *) INT2PTR(i));
+	    entry = Tcl_FindHashEntry(table, KEY(i));
 	    if (entry != NULL) {
 		clientData = Tcl_GetHashValue(entry);
 		Tcl_DeleteHashEntry(entry);
-		entry = Tcl_CreateHashEntry(table,
-			(char *) INT2PTR(i + offset), &isNew);
+		entry = Tcl_CreateHashEntry(table, KEY(i + offset), &isNew);
 		Tcl_SetHashValue(entry, clientData);
 	    }
 	}
diff --git a/generic/tkObj.c b/generic/tkObj.c
index 8877d42..29a235a 100644
--- a/generic/tkObj.c
+++ b/generic/tkObj.c
@@ -506,6 +506,7 @@ SetPixelFromAny(
     if (interp != NULL) {
 	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
 		"bad screen distance \"%.50s\"", string));
+	Tcl_SetErrorCode(interp, "TK", "VALUE", "PIXELS", NULL);
     }
     return TCL_ERROR;
 }
@@ -736,6 +737,7 @@ SetMMFromAny(
 	error:
 	    Tcl_AppendResult(interp, "bad screen distance \"", string,
 		    "\"", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "VALUE", "DISTANCE", NULL);
 	    return TCL_ERROR;
 	}
 	while ((*rest != '\0') && isspace(UCHAR(*rest))) {
@@ -1036,6 +1038,7 @@ TkParsePadAmount(
 	    Tcl_AppendResult(interp, "bad pad value \"",
 		    Tcl_GetString(specObj),
 		    "\": must be positive screen distance", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "VALUE", "PADDING", "DIST", NULL);
 	    return TCL_ERROR;
 	}
 	secondInt = firstInt;
@@ -1053,6 +1056,7 @@ TkParsePadAmount(
     if (objc != 1 && objc != 2) {
 	Tcl_AppendResult(interp,
 		"wrong number of parts to pad specification", NULL);
+	Tcl_SetErrorCode(interp, "TK", "VALUE", "PADDING", "PARTS", NULL);
 	return TCL_ERROR;
     }
 
@@ -1065,6 +1069,7 @@ TkParsePadAmount(
 	Tcl_ResetResult(interp);
 	Tcl_AppendResult(interp, "bad pad value \"", Tcl_GetString(objv[0]),
 		"\": must be positive screen distance", NULL);
+	Tcl_SetErrorCode(interp, "TK", "VALUE", "PADDING", "DIST", NULL);
 	return TCL_ERROR;
     }
 
@@ -1081,6 +1086,7 @@ TkParsePadAmount(
 	Tcl_AppendResult(interp, "bad 2nd pad value \"",
 		Tcl_GetString(objv[1]),
 		"\": must be positive screen distance", NULL);
+	Tcl_SetErrorCode(interp, "TK", "VALUE", "PADDING", "DIST", NULL);
 	return TCL_ERROR;
     }
 
diff --git a/generic/tkOldConfig.c b/generic/tkOldConfig.c
index 1ab6ab6..49d505e 100644
--- a/generic/tkOldConfig.c
+++ b/generic/tkOldConfig.c
@@ -96,6 +96,7 @@ Tk_ConfigureWidget(
 	 */
 
 	Tcl_AppendResult(interp, "NULL main window", NULL);
+	Tcl_SetErrorCode(interp, "TK", "NO_MAIN_WINDOW", NULL);
 	return TCL_ERROR;
     }
 
@@ -136,6 +137,7 @@ Tk_ConfigureWidget(
 
 	if (argc < 2) {
 	    Tcl_AppendResult(interp, "value for \"", arg, "\" missing", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "VALUE_MISSING", NULL);
 	    return TCL_ERROR;
 	}
 	if (flags & TK_CONFIG_OBJS) {
@@ -144,11 +146,8 @@ Tk_ConfigureWidget(
 	    arg = argv[1];
 	}
 	if (DoConfig(interp, tkwin, specPtr, arg, 0, widgRec) != TCL_OK) {
-	    char msg[100];
-
-	    sprintf(msg, "\n    (processing \"%.40s\" option)",
-		    specPtr->argvName);
-	    Tcl_AddErrorInfo(interp, msg);
+	    Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
+		    "\n    (processing \"%.40s\" option)",specPtr->argvName));
 	    return TCL_ERROR;
 	}
 	if (!(flags & TK_CONFIG_ARGV_ONLY)) {
@@ -181,12 +180,10 @@ Tk_ConfigureWidget(
 	    if (value != NULL) {
 		if (DoConfig(interp, tkwin, specPtr, value, 1, widgRec) !=
 			TCL_OK) {
-		    char msg[200];
-
-		    sprintf(msg, "\n    (%s \"%.50s\" in widget \"%.50s\")",
-			    "database entry for",
-			    specPtr->dbName, Tk_PathName(tkwin));
-		    Tcl_AddErrorInfo(interp, msg);
+		    Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
+			    "\n    (%s \"%.50s\" in widget \"%.50s\")",
+			    "database entry for", specPtr->dbName,
+			    Tk_PathName(tkwin)));
 		    return TCL_ERROR;
 		}
 	    } else {
@@ -199,13 +196,10 @@ Tk_ConfigureWidget(
 			& TK_CONFIG_DONT_SET_DEFAULT)) {
 		    if (DoConfig(interp, tkwin, specPtr, value, 1, widgRec) !=
 			    TCL_OK) {
-			char msg[200];
-
-			sprintf(msg,
+			Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
 				"\n    (%s \"%.50s\" in widget \"%.50s\")",
-				"default value for",
-				specPtr->dbName, Tk_PathName(tkwin));
-			Tcl_AddErrorInfo(interp, msg);
+				"default value for", specPtr->dbName,
+				Tk_PathName(tkwin)));
 			return TCL_ERROR;
 		    }
 		}
@@ -274,6 +268,7 @@ FindConfigSpec(
 	if (matchPtr != NULL) {
 	    Tcl_AppendResult(interp, "ambiguous option \"", argvName,
 		    "\"", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "OPTION", argvName,NULL);
 	    return NULL;
 	}
 	matchPtr = specPtr;
@@ -281,6 +276,7 @@ FindConfigSpec(
 
     if (matchPtr == NULL) {
 	Tcl_AppendResult(interp, "unknown option \"", argvName, "\"", NULL);
+	Tcl_SetErrorCode(interp, "TK", "LOOKUP", "OPTION", argvName, NULL);
 	return NULL;
     }
 
@@ -296,6 +292,8 @@ FindConfigSpec(
 	    if (specPtr->type == TK_CONFIG_END) {
 		Tcl_AppendResult(interp, "couldn't find synonym for option \"",
 			argvName, "\"", NULL);
+		Tcl_SetErrorCode(interp, "TK", "LOOKUP", "OPTION", argvName,
+			NULL);
 		return NULL;
 	    }
 	    if ((specPtr->dbName == matchPtr->dbName)
@@ -546,14 +544,12 @@ DoConfig(
 		return TCL_ERROR;
 	    }
 	    break;
-	default: {
-	    char buf[64 + TCL_INTEGER_SPACE];
-
-	    sprintf(buf, "bad config table: unknown type %d", specPtr->type);
-	    Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	default:
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "bad config table: unknown type %d", specPtr->type));
+	    Tcl_SetErrorCode(interp, "TK", "BAD_CONFIG", NULL);
 	    return TCL_ERROR;
 	}
-	}
 	specPtr++;
     } while ((specPtr->argvName == NULL) && (specPtr->type != TK_CONFIG_END));
     return TCL_OK;
diff --git a/generic/tkOption.c b/generic/tkOption.c
index d5c423f..a258bb0 100644
--- a/generic/tkOption.c
+++ b/generic/tkOption.c
@@ -541,7 +541,7 @@ Tk_GetOption(
 
 	winClassId = Tk_GetUid(masqClass);
 	ckfree(masqClass);
-	winNameId = ((TkWindow *)tkwin)->nameUid;
+	winNameId = ((TkWindow *) tkwin)->nameUid;
 
 	levelPtr = &tsdPtr->levels[tsdPtr->curLevel];
 
@@ -619,11 +619,9 @@ Tk_OptionObjCmd(
     int index, result;
     ThreadSpecificData *tsdPtr =
 	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
-
     static const char *const optionCmds[] = {
 	"add", "clear", "get", "readfile", NULL
     };
-
     enum optionVals {
 	OPTION_ADD, OPTION_CLEAR, OPTION_GET, OPTION_READFILE
     };
@@ -663,13 +661,12 @@ Tk_OptionObjCmd(
     }
 
     case OPTION_CLEAR: {
-	TkMainInfo *mainPtr;
+	TkMainInfo *mainPtr = ((TkWindow *) tkwin)->mainPtr;
 
 	if (objc != 2) {
 	    Tcl_WrongNumArgs(interp, 2, objv, "");
 	    return TCL_ERROR;
 	}
-	mainPtr = ((TkWindow *) tkwin)->mainPtr;
 	if (mainPtr->optionRootPtr != NULL) {
 	    ClearOptionTree(mainPtr->optionRootPtr);
 	    mainPtr->optionRootPtr = NULL;
@@ -883,6 +880,7 @@ ParsePriority(
 	    Tcl_AppendResult(interp, "bad priority level \"", string,
 		    "\": must be widgetDefault, startupFile, userDefault, ",
 		    "interactive, or a number between 0 and 100", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "VALUE", "PRIORITY", NULL);
 	    return -1;
 	}
     }
@@ -964,10 +962,9 @@ AddFromString(
 	dst = name = src;
 	while (*src != ':') {
 	    if ((*src == '\0') || (*src == '\n')) {
-		char buf[32 + TCL_INTEGER_SPACE];
-
-		sprintf(buf, "missing colon on line %d", lineNum);
-		Tcl_SetResult(interp, buf, TCL_VOLATILE);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"missing colon on line %d", lineNum));
+		Tcl_SetErrorCode(interp, "TK", "OPTIONDB", "COLON", NULL);
 		return TCL_ERROR;
 	    }
 	    if ((src[0] == '\\') && (src[1] == '\n')) {
@@ -999,10 +996,9 @@ AddFromString(
 	    src++;
 	}
 	if (*src == '\0') {
-	    char buf[32 + TCL_INTEGER_SPACE];
-
-	    sprintf(buf, "missing value on line %d", lineNum);
-	    Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "missing value on line %d", lineNum));
+	    Tcl_SetErrorCode(interp, "TK", "OPTIONDB", "VALUE", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -1014,10 +1010,9 @@ AddFromString(
 	dst = value = src;
 	while (*src != '\n') {
 	    if (*src == '\0') {
-		char buf[32 + TCL_INTEGER_SPACE];
-
-		sprintf(buf, "missing newline on line %d", lineNum);
-		Tcl_SetResult(interp, buf, TCL_VOLATILE);
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"missing newline on line %d", lineNum));
+		Tcl_SetErrorCode(interp, "TK", "OPTIONDB", "NEWLINE", NULL);
 		return TCL_ERROR;
 	    }
 	    if ((src[0] == '\\') && (src[1] == '\n')) {
@@ -1085,6 +1080,7 @@ ReadOptionFile(
     if (Tcl_IsSafe(interp)) {
 	Tcl_AppendResult(interp, "can't read options from a file in a",
 		" safe interpreter", NULL);
+	Tcl_SetErrorCode(interp, "TK", "OPTIONDB", "SAFE", NULL);
 	return TCL_ERROR;
     }
 
@@ -1309,6 +1305,7 @@ SetupStacks(
     if (tsdPtr->curLevel >= tsdPtr->numLevels) {
 	StackLevel *newLevels =
 		ckalloc(tsdPtr->numLevels * 2 * sizeof(StackLevel));
+
 	memcpy(newLevels, tsdPtr->levels,
 		tsdPtr->numLevels * sizeof(StackLevel));
 	ckfree(tsdPtr->levels);
diff --git a/generic/tkPack.c b/generic/tkPack.c
index b32cc23..3c3b389 100644
--- a/generic/tkPack.c
+++ b/generic/tkPack.c
@@ -152,11 +152,12 @@ void
 TkPrintPadAmount(
     Tcl_Interp *interp,		/* The interpreter into which the result is
 				 * written. */
-    const char *switchName,		/* One of "padx", "pady", "ipadx" or "ipady" */
+    const char *switchName,	/* One of "padx", "pady", "ipadx" or "ipady" */
     int halfSpace,		/* The left or top padding amount */
     int allSpace)		/* The total amount of padding */
 {
     char buffer[60 + 2*TCL_INTEGER_SPACE];
+
     if (halfSpace*2 == allSpace) {
 	sprintf(buffer, " -%.10s %d", switchName, halfSpace);
     } else {
@@ -240,6 +241,7 @@ Tk_PackObjCmd(
 	if (prevPtr->masterPtr == NULL) {
 	    Tcl_AppendResult(interp, "window \"", argv2,
 		    "\" isn't packed", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PACK", "NOT_PACKED", NULL);
 	    return TCL_ERROR;
 	}
 	return PackAfter(interp, prevPtr, prevPtr->masterPtr, objc-3, objv+3);
@@ -273,6 +275,7 @@ Tk_PackObjCmd(
 	if (packPtr->masterPtr == NULL) {
 	    Tcl_AppendResult(interp, "window \"", argv2,
 		    "\" isn't packed", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PACK", "NOT_PACKED", NULL);
 	    return TCL_ERROR;
 	}
 	masterPtr = packPtr->masterPtr;
@@ -295,6 +298,7 @@ Tk_PackObjCmd(
 	if (argv2[0] != '.') {
 	    Tcl_AppendResult(interp, "bad argument \"", argv2,
 		    "\": must be name of window", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "VALUE", "WINDOW", NULL);
 	    return TCL_ERROR;
 	}
 	return ConfigureSlaves(interp, tkwin, objc-2, objv+2);
@@ -335,6 +339,7 @@ Tk_PackObjCmd(
 	if (slavePtr->masterPtr == NULL) {
 	    Tcl_AppendResult(interp, "window \"", argv2,
 		    "\" isn't packed", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "PACK", "NOT_PACKED", NULL);
 	    return TCL_ERROR;
 	}
 	Tcl_AppendElement(interp, "-in");
@@ -1099,6 +1104,7 @@ PackAfter(
 	    Tcl_AppendResult(interp, "wrong # args: window \"",
 		    Tcl_GetString(objv[0]), "\" should be followed by options",
 		    NULL);
+	    Tcl_SetErrorCode(interp, "TCL", "WRONGARGS", NULL);
 	    return TCL_ERROR;
 	}
 
@@ -1122,6 +1128,7 @@ PackAfter(
 	    badWindow:
 		Tcl_AppendResult(interp, "can't pack ", Tcl_GetString(objv[0]),
 			" inside ", Tk_PathName(masterPtr->tkwin), NULL);
+		Tcl_SetErrorCode(interp, "TK", "GEOMETRY", "HIERARCHY", NULL);
 		return TCL_ERROR;
 	    }
 	}
@@ -1182,6 +1189,8 @@ PackAfter(
 		    Tcl_AppendResult(interp, "wrong # args: \"", curOpt,
 			    "\" option must be followed by screen distance",
 			    NULL);
+		    Tcl_SetErrorCode(interp, "TK", "OLDPACK", "BAD_PARAMETER",
+			    NULL);
 		    return TCL_ERROR;
 		}
 		if (TkParsePadAmount(interp, tkwin, options[index+1],
@@ -1209,6 +1218,8 @@ PackAfter(
 		if (optionCount < (index+2)) {
 		    Tcl_AppendResult(interp, "wrong # args: \"frame\" ",
 			    "option must be followed by anchor point", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "OLDPACK", "BAD_PARAMETER",
+			    NULL);
 		    return TCL_ERROR;
 		}
 		if (Tk_GetAnchorFromObj(interp, options[index+1],
@@ -1220,6 +1231,8 @@ PackAfter(
 		Tcl_AppendResult(interp, "bad option \"", curOpt,
 			"\": should be top, bottom, left, right, expand, ",
 			"fill, fillx, filly, padx, pady, or frame", NULL);
+		Tcl_SetErrorCode(interp, "TK", "OLDPACK", "BAD_PARAMETER",
+			NULL);
 		return TCL_ERROR;
 	    }
 	}
@@ -1536,6 +1549,7 @@ ConfigureSlaves(
 	if (Tk_TopWinHierarchy(slave)) {
 	    Tcl_AppendResult(interp, "can't pack \"", Tcl_GetString(objv[j]),
 		    "\": it's a top-level window", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GEOMETRY", "TOPLEVEL", NULL);
 	    return TCL_ERROR;
 	}
 	slavePtr = GetPacker(slave);
@@ -1561,6 +1575,7 @@ ConfigureSlaves(
 		Tcl_AppendResult(interp, "extra option \"",
 			Tcl_GetString(objv[i]),
 			"\" (option with no value?)", NULL);
+		Tcl_SetErrorCode(interp, "TK", "PACK", "BAD_PARAMETER", NULL);
 		return TCL_ERROR;
 	    }
 	    if (Tcl_GetIndexFromObj(interp, objv[i], optionStrings, "option",
@@ -1581,6 +1596,8 @@ ConfigureSlaves(
 			Tcl_AppendResult(interp, "window \"",
 				Tcl_GetString(objv[i+1]), "\" isn't packed",
 				NULL);
+			Tcl_SetErrorCode(interp, "TK", "PACK", "NOT_PACKED",
+				NULL);
 			return TCL_ERROR;
 		    }
 		    masterPtr = prevPtr->masterPtr;
@@ -1637,6 +1654,7 @@ ConfigureSlaves(
 		} else {
 		    Tcl_AppendResult(interp, "bad fill style \"", string,
 			    "\": must be none, x, y, or both", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "VALUE", "FILL", NULL);
 		    return TCL_ERROR;
 		}
 		break;
@@ -1664,6 +1682,7 @@ ConfigureSlaves(
 		    Tcl_AppendResult(interp, "bad ipadx value \"",
 			    Tcl_GetString(objv[i+1]),
 			    "\": must be positive screen distance", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "VALUE", "INT_PAD", NULL);
 		    return TCL_ERROR;
 		}
 		slavePtr->iPadX = tmp * 2;
@@ -1676,6 +1695,7 @@ ConfigureSlaves(
 		    Tcl_AppendResult(interp, "bad ipady value \"",
 			    Tcl_GetString(objv[i+1]),
 			    "\": must be positive screen distance", NULL);
+		    Tcl_SetErrorCode(interp, "TK", "VALUE", "INT_PAD", NULL);
 		    return TCL_ERROR;
 		}
 		slavePtr->iPadY = tmp * 2;
@@ -1754,12 +1774,14 @@ ConfigureSlaves(
 	    if (Tk_TopWinHierarchy(ancestor)) {
 		Tcl_AppendResult(interp, "can't pack ", Tcl_GetString(objv[j]),
 			" inside ", Tk_PathName(masterPtr->tkwin), NULL);
+		Tcl_SetErrorCode(interp, "TK", "GEOMETRY", "HIERARCHY", NULL);
 		return TCL_ERROR;
 	    }
 	}
 	if (slave == masterPtr->tkwin) {
 	    Tcl_AppendResult(interp, "can't pack ", Tcl_GetString(objv[j]),
 		    " inside itself", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GEOMETRY", "SELF", NULL);
 	    return TCL_ERROR;
 	}
 
diff --git a/generic/tkPlace.c b/generic/tkPlace.c
index 22072ce..a0d3562 100644
--- a/generic/tkPlace.c
+++ b/generic/tkPlace.c
@@ -621,6 +621,7 @@ ConfigureSlave(
     if (Tk_TopWinHierarchy(tkwin)) {
 	Tcl_AppendResult(interp, "can't use placer on top-level window \"",
 		Tk_PathName(tkwin), "\"; use wm command instead", NULL);
+	Tcl_SetErrorCode(interp, "TK", "GEOMETRY", "TOPLEVEL", NULL);
 	return TCL_ERROR;
     }
 
@@ -681,6 +682,7 @@ ConfigureSlave(
 		Tcl_AppendResult(interp, "can't place ",
 			Tk_PathName(slavePtr->tkwin), " relative to ",
 			Tk_PathName(tkwin), NULL);
+		Tcl_SetErrorCode(interp, "TK", "GEOMETRY", "HIERARCHY", NULL);
 		goto error;
 	    }
 	}
@@ -688,6 +690,7 @@ ConfigureSlave(
 	    Tcl_AppendResult(interp, "can't place ",
 		    Tk_PathName(slavePtr->tkwin), " relative to itself",
 		    NULL);
+	    Tcl_SetErrorCode(interp, "TK", "GEOMETRY", "LOOP", NULL);
 	    goto error;
 	}
 	if ((slavePtr->masterPtr != NULL)
diff --git a/generic/tkRectOval.c b/generic/tkRectOval.c
index 630737c..c41387c 100644
--- a/generic/tkRectOval.c
+++ b/generic/tkRectOval.c
@@ -348,10 +348,8 @@ RectOvalCoords(
      */
 
     if (objc != 4) {
-	char buf[64 + TCL_INTEGER_SPACE];
-
-	sprintf(buf, "wrong # coordinates: expected 0 or 4, got %d", objc);
-	Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"wrong # coordinates: expected 0 or 4, got %d", objc));
 	return TCL_ERROR;
     }
 
diff --git a/generic/tkStubInit.c b/generic/tkStubInit.c
index 271243e..b1cdd53 100644
--- a/generic/tkStubInit.c
+++ b/generic/tkStubInit.c
@@ -55,7 +55,7 @@ TkpSync(Display *display)
 void
 TkCreateXEventSource(void)
 {
-	TkWinXInit(Tk_GetHINSTANCE());
+    TkWinXInit(Tk_GetHINSTANCE());
 }
 
 #   define TkUnixContainerId 0
@@ -105,7 +105,7 @@ TkpPrintWindowId(
 				 * the hex representation of a pointer. */
     Window window)		/* Window to be printed into buffer. */
 {
-	sprintf(buf, "%#08lx", (unsigned long) (window));
+    sprintf(buf, "%#08lx", (unsigned long) (window));
 }
 
 int
diff --git a/generic/tkStyle.c b/generic/tkStyle.c
index 76291fa..965230e 100644
--- a/generic/tkStyle.c
+++ b/generic/tkStyle.c
@@ -1358,6 +1358,7 @@ Tk_GetStyle(
 	if (interp != NULL) {
 	    Tcl_AppendResult(interp, "style \"", name, "\" doesn't exist",
 		    NULL);
+	    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "STYLE", name, NULL);
 	}
 	return (Tk_Style) NULL;
     }
diff --git a/generic/tkUtil.c b/generic/tkUtil.c
index 5282708..b0ea2ea 100644
--- a/generic/tkUtil.c
+++ b/generic/tkUtil.c
@@ -96,6 +96,7 @@ TkStateParseProc(
 	Tcl_AppendResult(interp, ",", NULL);
     }
     Tcl_AppendResult(interp, " or disabled", NULL);
+    Tcl_SetErrorCode(interp, "TK", "VALUE", "STATE", NULL);
     *statePtr = TK_STATE_NORMAL;
     return TCL_ERROR;
 }
@@ -197,6 +198,7 @@ TkOrientParseProc(
     }
     Tcl_AppendResult(interp, "bad orientation \"", value,
 	    "\": must be vertical or horizontal", NULL);
+    Tcl_SetErrorCode(interp, "TK", "VALUE", "ORIENTATION", NULL);
     *orientPtr = 0;
     return TCL_ERROR;
 }
@@ -385,6 +387,7 @@ TkOffsetParseProc(
 	Tcl_AppendResult(interp, ", <index>", NULL);
     }
     Tcl_AppendResult(interp, ", n, ne, e, se, s, sw, w, nw, or center", NULL);
+    Tcl_SetErrorCode(interp, "TK", "VALUE", "OFFSET", NULL);
     return TCL_ERROR;
 }
 
@@ -482,6 +485,7 @@ TkPixelParseProc(
 
     if ((result == TCL_OK) && (clientData == NULL) && (*doublePtr < 0.0)) {
 	Tcl_AppendResult(interp, "bad screen distance \"", value, "\"", NULL);
+	Tcl_SetErrorCode(interp, "TK", "VALUE", "PIXELS", NULL);
 	return TCL_ERROR;
     }
     return result;
@@ -646,6 +650,7 @@ Tk_GetScrollInfo(
 	if (argc != 4) {
 	    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
 		    " ", argv[1], " moveto fraction\"", NULL);
+	    Tcl_SetErrorCode(interp, "TCL", "WRONGARGS", NULL);
 	    return TK_SCROLL_ERROR;
 	}
 	if (Tcl_GetDouble(interp, argv[3], dblPtr) != TCL_OK) {
@@ -657,6 +662,7 @@ Tk_GetScrollInfo(
 	if (argc != 5) {
 	    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
 		    " ", argv[1], " scroll number units|pages\"", NULL);
+	    Tcl_SetErrorCode(interp, "TCL", "WRONGARGS", NULL);
 	    return TK_SCROLL_ERROR;
 	}
 	if (Tcl_GetInt(interp, argv[3], intPtr) != TCL_OK) {
@@ -672,10 +678,13 @@ Tk_GetScrollInfo(
 
 	Tcl_AppendResult(interp, "bad argument \"", argv[4],
 		"\": must be units or pages", NULL);
+	Tcl_SetErrorCode(interp, "TK", "VALUE", "SCROLL_UNITS", NULL);
 	return TK_SCROLL_ERROR;
     }
     Tcl_AppendResult(interp, "unknown option \"", argv[2],
 	    "\": must be moveto or scroll", NULL);
+    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "INDEX", "option", argv[2],
+	    NULL);
     return TK_SCROLL_ERROR;
 }
 
@@ -746,10 +755,12 @@ Tk_GetScrollInfoObj(
 
 	Tcl_AppendResult(interp, "bad argument \"", arg,
 		"\": must be units or pages", NULL);
+	Tcl_SetErrorCode(interp, "TK", "VALUE", "SCROLL_UNITS", NULL);
 	return TK_SCROLL_ERROR;
     }
     Tcl_AppendResult(interp, "unknown option \"", arg,
 	    "\": must be moveto or scroll", NULL);
+    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "INDEX", "option", arg, NULL);
     return TK_SCROLL_ERROR;
 }
 
@@ -916,6 +927,7 @@ TkFindStateNum(
 	mPtr = mapPtr;
 	Tcl_AppendResult(interp, "bad ", option, " value \"", strKey,
 		"\": must be ", mPtr->strKey, NULL);
+	Tcl_SetErrorCode(interp, "TK", "VALUE", option, NULL);
 	for (mPtr++; mPtr->strKey != NULL; mPtr++) {
 	    Tcl_AppendResult(interp,
 		    ((mPtr[1].strKey != NULL) ? ", " : ", or "),
@@ -972,6 +984,8 @@ TkFindStateNumObj(
 	mPtr = mapPtr;
 	Tcl_AppendResult(interp, "bad ", Tcl_GetString(optionPtr),
 		" value \"", key, "\": must be ", mPtr->strKey, NULL);
+	Tcl_SetErrorCode(interp, "TK", "VALUE", Tcl_GetString(optionPtr),
+		NULL);
 	for (mPtr++; mPtr->strKey != NULL; mPtr++) {
 	    Tcl_AppendResult(interp,
 		((mPtr[1].strKey != NULL) ? ", " : ", or "),
diff --git a/generic/tkVisual.c b/generic/tkVisual.c
index 3602088..b19e78c 100644
--- a/generic/tkVisual.c
+++ b/generic/tkVisual.c
@@ -176,6 +176,7 @@ Tk_GetVisual(
 	    Tcl_ResetResult(interp);
 	    Tcl_AppendResult(interp, "bad X identifier for visual: \"",
 		    string, "\"", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "VALUE", "VISUALID", NULL);
 	    return NULL;
 	}
 	template.visualid = visualId;
@@ -204,6 +205,7 @@ Tk_GetVisual(
 	if (template.class == -1) {
 	    Tcl_AppendResult(interp, "unknown or ambiguous visual name \"",
 		    string, "\": class must be ", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "VALUE", "VISUAL", NULL);
 	    for (dictPtr = visualNames; dictPtr->name != NULL; dictPtr++) {
 		Tcl_AppendResult(interp, dictPtr->name, ", ", NULL);
 	    }
@@ -239,6 +241,7 @@ Tk_GetVisual(
     if (visInfoList == NULL) {
 	Tcl_SetResult(interp, "couldn't find an appropriate visual",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "VISUAL", "INAPPROPRIATE", NULL);
 	return NULL;
     }
 
@@ -405,11 +408,13 @@ Tk_GetColormap(
     if (Tk_Screen(other) != Tk_Screen(tkwin)) {
 	Tcl_AppendResult(interp, "can't use colormap for ", string,
 		": not on same screen", NULL);
+	Tcl_SetErrorCode(interp, "TK", "COLORMAP", "SCREEN", NULL);
 	return None;
     }
     if (Tk_Visual(other) != Tk_Visual(tkwin)) {
 	Tcl_AppendResult(interp, "can't use colormap for ", string,
 		": incompatible visuals", NULL);
+	Tcl_SetErrorCode(interp, "TK", "COLORMAP", "INCOMPATIBLE", NULL);
 	return None;
     }
     colormap = Tk_Colormap(other);
diff --git a/generic/tkWindow.c b/generic/tkWindow.c
index b04b95f..27fba69 100644
--- a/generic/tkWindow.c
+++ b/generic/tkWindow.c
@@ -103,8 +103,9 @@ static const XSetWindowAttributes defAtts= {
 
 typedef int (TkInitProc)(Tcl_Interp *interp, ClientData clientData);
 typedef struct {
-    const char *name;			/* Name of command. */
-    Tcl_ObjCmdProc *objProc;	/* Command's object- (or string-) based function, or initProc. */
+    const char *name;		/* Name of command. */
+    Tcl_ObjCmdProc *objProc;	/* Command's object- (or string-) based
+				 * function, or initProc. */
     int flags;
 } TkCmd;
 
@@ -153,7 +154,8 @@ static const TkCmd commands[] = {
     {"panedwindow",	Tk_PanedWindowObjCmd,	ISSAFE},
     {"radiobutton",	Tk_RadiobuttonObjCmd,	ISSAFE},
     {"scale",		Tk_ScaleObjCmd,		ISSAFE},
-    {"scrollbar",	(Tcl_ObjCmdProc *) Tk_ScrollbarCmd,	NOOBJPROC|PASSMAINWINDOW|ISSAFE},
+    {"scrollbar",	(Tcl_ObjCmdProc *) Tk_ScrollbarCmd,
+					NOOBJPROC|PASSMAINWINDOW|ISSAFE},
     {"spinbox",		Tk_SpinboxObjCmd,	ISSAFE},
     {"text",		Tk_TextObjCmd,		PASSMAINWINDOW|ISSAFE},
     {"toplevel",	Tk_ToplevelObjCmd,	0},
@@ -175,7 +177,8 @@ static const TkCmd commands[] = {
     {"::tk::panedwindow",Tk_PanedWindowObjCmd,	ISSAFE},
     {"::tk::radiobutton",Tk_RadiobuttonObjCmd,	ISSAFE},
     {"::tk::scale",	Tk_ScaleObjCmd,		ISSAFE},
-    {"::tk::scrollbar",	(Tcl_ObjCmdProc *) Tk_ScrollbarCmd,			NOOBJPROC|PASSMAINWINDOW|ISSAFE},
+    {"::tk::scrollbar",	(Tcl_ObjCmdProc *) Tk_ScrollbarCmd,
+					NOOBJPROC|PASSMAINWINDOW|ISSAFE},
     {"::tk::spinbox",	Tk_SpinboxObjCmd,	ISSAFE},
     {"::tk::text",	Tk_TextObjCmd,		PASSMAINWINDOW|ISSAFE},
     {"::tk::toplevel",	Tk_ToplevelObjCmd,	0},
@@ -197,7 +200,7 @@ static const TkCmd commands[] = {
      * Misc.
      */
 
-#if defined(MAC_OSX_TK)
+#ifdef MAC_OSX_TK
     {"::tk::unsupported::MacWindowStyle",
 			TkUnsupported1ObjCmd,	PASSMAINWINDOW|ISSAFE},
 #endif
@@ -290,6 +293,7 @@ TkCloseDisplay(
 
     if (dispPtr->errorPtr != NULL) {
 	TkErrorHandler *errorPtr;
+
 	for (errorPtr = dispPtr->errorPtr;
 		errorPtr != NULL;
 		errorPtr = dispPtr->errorPtr) {
@@ -470,6 +474,7 @@ GetScreen(
 	Tcl_SetResult(interp,
 		"no display name and no $DISPLAY environment variable",
 		TCL_STATIC);
+	Tcl_SetErrorCode(interp, "TK", "NO_DISPLAY", NULL);
 	return NULL;
     }
     length = strlen(screenName);
@@ -500,6 +505,7 @@ GetScreen(
 		Tcl_ResetResult(interp);
 		Tcl_AppendResult(interp, "couldn't connect to display \"",
 			screenName, "\"", NULL);
+		Tcl_SetErrorCode(interp, "TK", "DISPLAY", "CONNECTION", NULL);
 		return NULL;
 	    }
 	    dispPtr->nextPtr = tsdPtr->displayList; /* TkGetDisplayList(); */
@@ -531,10 +537,9 @@ GetScreen(
 	}
     }
     if (screenId >= ScreenCount(dispPtr->display)) {
-	char buf[32 + TCL_INTEGER_SPACE];
-
-	sprintf(buf, "bad screen number \"%d\"", screenId);
-	Tcl_SetResult(interp, buf, TCL_VOLATILE);
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"bad screen number \"%d\"", screenId));
+	Tcl_SetErrorCode(interp, "TK", "DISPLAY", "SCREEN_NUMBER", NULL);
 	return NULL;
     }
     *screenPtr = screenId;
@@ -774,12 +779,6 @@ NameWindow(
     }
 
     /*
-     * For non-anonymous windows, set up the window name.
-     */
-
-    winPtr->nameUid = Tk_GetUid(name);
-
-    /*
      * Don't permit names that start with an upper-case letter: this will just
      * cause confusion with class names in the option database.
      */
@@ -788,10 +787,17 @@ NameWindow(
 	Tcl_AppendResult(interp,
 		"window name starts with an upper-case letter: \"",
 		name, "\"", NULL);
+	Tcl_SetErrorCode(interp, "TK", "VALUE", "WINDOW", "NOTCLASS", NULL);
 	return TCL_ERROR;
     }
 
     /*
+     * For non-anonymous windows, set up the window name.
+     */
+
+    winPtr->nameUid = Tk_GetUid(name);
+
+    /*
      * To permit names of arbitrary length, must be prepared to malloc a
      * buffer to hold the new path name. To run fast in the common case where
      * names are short, use a fixed-size buffer on the stack.
@@ -820,6 +826,7 @@ NameWindow(
     if (!isNew) {
 	Tcl_AppendResult(interp, "window name \"", name,
 		"\" already exists in parent", NULL);
+	Tcl_SetErrorCode(interp, "TK", "VALUE", "WINDOW", "EXISTS", NULL);
 	return TCL_ERROR;
     }
     Tcl_SetHashValue(hPtr, winPtr);
@@ -964,7 +971,7 @@ TkCreateMainWindow(
 	    clientData = NULL;
 	}
 	if (cmdPtr->flags & USEINITPROC) {
-	    ((TkInitProc *)cmdPtr->objProc)(interp, clientData);
+	    ((TkInitProc *) cmdPtr->objProc)(interp, clientData);
 	} else if (cmdPtr->flags & NOOBJPROC) {
 	    Tcl_CreateCommand(interp, cmdPtr->name,
 		    (Tcl_CmdProc *) cmdPtr->objProc, clientData, NULL);
@@ -972,10 +979,8 @@ TkCreateMainWindow(
 	    Tcl_CreateObjCommand(interp, cmdPtr->name, cmdPtr->objProc,
 		    clientData, NULL);
 	}
-	if (isSafe) {
-	    if (!(cmdPtr->flags & ISSAFE)) {
-		Tcl_HideCommand(interp, cmdPtr->name, cmdPtr->name);
-	    }
+	if (isSafe && !(cmdPtr->flags & ISSAFE)) {
+	    Tcl_HideCommand(interp, cmdPtr->name, cmdPtr->name);
 	}
     }
 
@@ -1034,11 +1039,13 @@ Tk_CreateWindow(
 	if (parentPtr->flags & TK_ALREADY_DEAD) {
 	    Tcl_AppendResult(interp,
 		    "can't create window: parent has been destroyed", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "CREATE", "DEAD_PARENT", NULL);
 	    return NULL;
 	} else if (parentPtr->flags & TK_CONTAINER) {
 	    Tcl_AppendResult(interp,
 		    "can't create window: its parent has -container = yes",
 		    NULL);
+	    Tcl_SetErrorCode(interp, "TK", "CREATE", "CONTAINER", NULL);
 	    return NULL;
 	} else if (screenName == NULL) {
 	    TkWindow *winPtr = TkAllocWindow(parentPtr->dispPtr,
@@ -1096,11 +1103,13 @@ Tk_CreateAnonymousWindow(
 	if (parentPtr->flags & TK_ALREADY_DEAD) {
 	    Tcl_AppendResult(interp,
 		    "can't create window: parent has been destroyed", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "CREATE", "DEAD_PARENT", NULL);
 	    return NULL;
 	} else if (parentPtr->flags & TK_CONTAINER) {
 	    Tcl_AppendResult(interp,
 		    "can't create window: its parent has -container = yes",
 		    NULL);
+	    Tcl_SetErrorCode(interp, "TK", "CREATE", "CONTAINER", NULL);
 	    return NULL;
 	} else if (screenName == NULL) {
 	    TkWindow *winPtr = TkAllocWindow(parentPtr->dispPtr,
@@ -1178,6 +1187,7 @@ Tk_CreateWindowFromPath(
     if (p == NULL) {
 	Tcl_AppendResult(interp, "bad window path name \"", pathName,
 		"\"", NULL);
+	Tcl_SetErrorCode(interp, "TK", "VALUE", "WINDOWPATH", NULL);
 	return NULL;
     }
     numChars = (int) (p-pathName);
@@ -1208,11 +1218,13 @@ Tk_CreateWindowFromPath(
     if (((TkWindow *) parent)->flags & TK_ALREADY_DEAD) {
 	Tcl_AppendResult(interp,
 		"can't create window: parent has been destroyed", NULL);
+	Tcl_SetErrorCode(interp, "TK", "CREATE", "DEAD_PARENT", NULL);
 	return NULL;
     }
     if (((TkWindow *) parent)->flags & TK_CONTAINER) {
 	Tcl_AppendResult(interp,
 		"can't create window: its parent has -container = yes", NULL);
+	Tcl_SetErrorCode(interp, "TK", "CREATE", "CONTAINER", NULL);
 	return NULL;
     }
 
@@ -1354,8 +1366,8 @@ Tk_DestroyWindow(
     }
 
     while (winPtr->childList != NULL) {
-	TkWindow *childPtr;
-	childPtr = winPtr->childList;
+	TkWindow *childPtr = winPtr->childList;
+
 	childPtr->flags |= TK_DONT_DESTROY_WINDOW;
 	Tk_DestroyWindow((Tk_Window) childPtr);
 	if (winPtr->childList == childPtr) {
@@ -1382,8 +1394,8 @@ Tk_DestroyWindow(
 	 * deleted, in which case TkpGetOtherWindow will return NULL.
 	 */
 
-	TkWindow *childPtr;
-	childPtr = TkpGetOtherWindow(winPtr);
+	TkWindow *childPtr = TkpGetOtherWindow(winPtr);
+
 	if (childPtr != NULL) {
 	    childPtr->flags |= TK_DONT_DESTROY_WINDOW;
 	    Tk_DestroyWindow((Tk_Window) childPtr);
@@ -1751,6 +1763,7 @@ Tk_MakeWindowExist(
 	    if ((winPtr2->window != None)
 		    && !(winPtr2->flags & (TK_TOP_HIERARCHY|TK_REPARENTED))) {
 		XWindowChanges changes;
+
 		changes.sibling = winPtr2->window;
 		changes.stack_mode = Below;
 		XConfigureWindow(winPtr->display, winPtr->window,
@@ -2328,7 +2341,8 @@ Tk_NameToWindow(
 	 */
 
 	if (interp != NULL) {
-	    Tcl_AppendResult(interp, "NULL main window", NULL);
+	    Tcl_SetResult(interp, "NULL main window", TCL_STATIC);
+	    Tcl_SetErrorCode(interp, "TK", "NO_MAIN_WINDOW", NULL);
 	}
 	return NULL;
     }
@@ -2339,6 +2353,7 @@ Tk_NameToWindow(
 	if (interp != NULL) {
 	    Tcl_AppendResult(interp, "bad window path name \"",
 		    pathName, "\"", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "VALUE", "WINDOWNAME", NULL);
 	}
 	return NULL;
     }
@@ -2591,9 +2606,8 @@ Tk_RestackWindow(
 
     if (winPtr->window != None) {
 	XWindowChanges changes;
-	unsigned int mask;
+	unsigned int mask = CWStackMode;
 
-	mask = CWStackMode;
 	changes.stack_mode = Above;
 	for (otherPtr = winPtr->nextPtr; otherPtr != NULL;
 		otherPtr = otherPtr->nextPtr) {
@@ -2653,6 +2667,7 @@ Tk_MainWindow(
 	}
     }
     Tcl_SetResult(interp, "this isn't a Tk application", TCL_STATIC);
+    Tcl_SetErrorCode(interp, "TK", "NO_MAIN_WINDOW", NULL);
     return NULL;
 }
 
@@ -2840,44 +2855,47 @@ static HMODULE tkcygwindll = NULL;
 /*
  * Run Tk_MainEx from libtk8.?.dll
  *
- * This function is only ever called from wish8.4.exe, the cygwin
- * port of Tcl. This means that the system encoding is utf-8,
- * so we don't have to do any encoding conversions.
+ * This function is only ever called from wish8.4.exe, the cygwin port of Tcl.
+ * This means that the system encoding is utf-8, so we don't have to do any
+ * encoding conversions.
  */
+
 int
-TkCygwinMainEx(argc, argv, appInitProc, interp)
-    int argc;				/* Number of arguments. */
-    char **argv;			/* Array of argument strings. */
-    Tcl_AppInitProc *appInitProc;	/* Application-specific initialization
-					 * procedure to call after most
-					 * initialization but before starting
-					 * to execute commands. */
-    Tcl_Interp *interp;
+TkCygwinMainEx(
+    int argc,			/* Number of arguments. */
+    char **argv,		/* Array of argument strings. */
+    Tcl_AppInitProc *appInitProc,
+				/* Application-specific initialization
+				 * procedure to call after most initialization
+				 * but before starting to execute commands. */
+    Tcl_Interp *interp)
 {
     TCHAR name[MAX_PATH];
     int len;
-    void (*sym)(int, char **, Tcl_AppInitProc *, Tcl_Interp *);
+    void (*tkmainex)(int, char **, Tcl_AppInitProc *, Tcl_Interp *);
 
     /* construct "<path>/libtk8.?.dll", from "<path>/tk8?.dll" */
-	len = GetModuleFileNameW(Tk_GetHINSTANCE(), name, MAX_PATH);
-	name[len-2] = TEXT('.');
-	name[len-1] = name[len-5];
-	_tcscpy(name+len, TEXT(".dll"));
-	memcpy(name+len-8, TEXT("libtk8"), 6 * sizeof(TCHAR));
-
-	tkcygwindll = LoadLibrary(name);
-	if (!tkcygwindll) {
-	    /* dll is not present */
-	    return 0;
-	}
-	sym = (void (*)(int, char **, Tcl_AppInitProc *, Tcl_Interp *)) GetProcAddress(tkcygwindll, "Tk_MainEx");
-	if (!sym) {
-		return 0;
-	}
-	sym(argc, argv, appInitProc, interp);
+    len = GetModuleFileNameW(Tk_GetHINSTANCE(), name, MAX_PATH);
+    name[len-2] = TEXT('.');
+    name[len-1] = name[len-5];
+    _tcscpy(name+len, TEXT(".dll"));
+    memcpy(name+len-8, TEXT("libtk8"), 6 * sizeof(TCHAR));
+
+    tkcygwindll = LoadLibrary(name);
+    if (!tkcygwindll) {
+	/* dll is not present */
+	return 0;
+    }
+    tkmainex = (void (*)(int, char **, Tcl_AppInitProc *, Tcl_Interp *))
+	    GetProcAddress(tkcygwindll, "Tk_MainEx");
+    if (!tkmainex) {
+	return 0;
+    }
+    tkmainex(argc, argv, appInitProc, interp);
     return 1;
 }
-#endif
+#endif /* __WIN32__ && !__WIN64__ */
+
 /*
  *----------------------------------------------------------------------
  *
@@ -2907,14 +2925,14 @@ Tk_Init(
 {
 #if defined(__WIN32__) && !defined(__WIN64__)
     if (tkcygwindll) {
-	int (*sym)(Tcl_Interp *);
+	int (*tkinit)(Tcl_Interp *);
 
-	sym = (int (*)(Tcl_Interp *)) GetProcAddress(tkcygwindll, "Tk_Init");
-	if (sym) {
-	    return sym(interp);
+	tkinit = (int(*)(Tcl_Interp *)) GetProcAddress(tkcygwindll,"Tk_Init");
+	if (tkinit) {
+	    return tkinit(interp);
 	}
     }
-#endif
+#endif /* __WIN32__ && !__WIN64__ */
     return Initialize(interp);
 }
 
@@ -2980,14 +2998,15 @@ Tk_SafeInit(
 
 #if defined(__WIN32__) && !defined(__WIN64__)
     if (tkcygwindll) {
-	int (*sym)(Tcl_Interp *);
+	int (*tksafeinit)(Tcl_Interp *);
 
-	sym = (int (*)(Tcl_Interp *)) GetProcAddress(tkcygwindll, "Tk_SafeInit");
-	if (sym) {
-	    return sym(interp);
+	tksafeinit = (int (*)(Tcl_Interp *))
+		GetProcAddress(tkcygwindll, "Tk_SafeInit");
+	if (tksafeinit) {
+	    return tksafeinit(interp);
 	}
     }
-#endif
+#endif /* __WIN32__ && !__WIN64__ */
     return Initialize(interp);
 }
 
@@ -2998,7 +3017,8 @@ MODULE_SCOPE const TkStubs tkStubs;
  *
  * Initialize --
  *
- *	???TODO???
+ *	The core of the initialization code for Tk, called from Tk_Init and
+ *	Tk_SafeInit.
  *
  * Results:
  *	A standard Tcl result. Also leaves an error message in the interp's
@@ -3083,6 +3103,7 @@ Initialize(
 	    master = Tcl_GetMaster(master);
 	    if (master == NULL) {
 		Tcl_AppendResult(interp, "NULL master", NULL);
+		Tcl_SetErrorCode(interp, "TK", "SAFE", "FAILED", NULL);
 		code = TCL_ERROR;
 		goto done;
 	    }
@@ -3099,6 +3120,7 @@ Initialize(
 	code = Tcl_GetInterpPath(master, interp);
 	if (code != TCL_OK) {
 	    Tcl_AppendResult(interp, "error in Tcl_GetInterpPath", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "SAFE", "FAILED", NULL);
 	    goto done;
 	}
 
@@ -3125,6 +3147,7 @@ Initialize(
 	    Tcl_DStringFree(&ds);
 	    Tcl_AppendResult(interp,
 		    "not allowed to start Tk by master's safe::TkInit", NULL);
+	    Tcl_SetErrorCode(interp, "TK", "SAFE", "FAILED", NULL);
 	    goto done;
 	}
 	Tcl_DStringFree(&ds);
@@ -3389,6 +3412,7 @@ Tk_PkgInitStubsCheck(
     }
     return actualVersion;
 }
+
 /*
  * Local Variables:
  * mode: c