Improve TclDuplicatePureObj(), remove unnecessary increment/decrement pairs, and add more error checking.

1 files changed, 11 insertions, 4 deletions

diff --git a/generic/tclIORChan.c b/generic/tclIORChan.c
index ada5768..c7cbfe5 100644
--- a/generic/tclIORChan.c
+++ b/generic/tclIORChan.c
@@ -580,6 +580,9 @@ TclChanCreateObjCmd(
 
     rcId = NextHandle();
     rcPtr = NewReflectedChannel(interp, cmdObj, mode, rcId);
+    if (!rcPtr) {
+	return TCL_ERROR;
+    }
 
     /*
      * Invoke 'initialize' and validate that the handler is present and ok.
@@ -2258,8 +2261,10 @@ NewReflectedChannel(
     rcPtr->mode = mode;
     rcPtr->interest = 0;		/* Initially no interest registered */
 
-    /* ASSERT: cmdpfxObj is a Tcl List */
-    rcPtr->cmd = TclDuplicatePureObj(cmdpfxObj);
+    rcPtr->cmd = TclDuplicatePureObj(interp, cmdpfxObj, &tclListType.objType);
+    if (!rcPtr->cmd) {
+	return NULL;
+    }
     Tcl_IncrRefCount(rcPtr->cmd);
     rcPtr->methods = Tcl_NewListObj(METH_WRITE + 1, NULL);
     while (mn <= (int)METH_WRITE) {
@@ -2396,8 +2401,10 @@ InvokeTclMethod(
      * before the channel id.
      */
 
-    cmd = TclDuplicatePureObj(rcPtr->cmd);
-
+    cmd = TclDuplicatePureObj(NULL, rcPtr->cmd, &tclListType.objType);
+    if (!cmd) {
+	return TCL_ERROR;
+    }
     Tcl_ListObjIndex(NULL, rcPtr->methods, method, &methObj);
     Tcl_ListObjAppendElement(NULL, cmd, methObj);
     Tcl_ListObjAppendElement(NULL, cmd, rcPtr->name);