* generic/tcl.h: Modified the Tcl call stack so

	* generic/tclBasic.c:      there is always a valid CallFrame, even
	* generic/tclCmdIL.c:      at level 0 [Patch 1577278]. Most of the
	* generic/tclInt.h:        changes involve removing tests for
	* generic/tclNamesp.c:     iPtr->(var)framePtr==NULL. There is now a
	* generic/tclObj.c:        CallFrame pushed at interp creation
	* generic/tclProc.c:       with a pointer to it stored in
	* generic/tclTrace.c:      iPtr->rootFramePtr. A second unused
	* generic/tclVar.c:        field in Interp is hijacked to enable
	further functionality, currently unused (but with several FRQs
	depending on it).

1 files changed, 18 insertions, 25 deletions

diff --git a/generic/tclProc.c b/generic/tclProc.c
index 6429488..e6a70ab 100644
--- a/generic/tclProc.c
+++ b/generic/tclProc.c
@@ -11,7 +11,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclProc.c,v 1.95 2006/10/20 15:16:47 dkf Exp $
+ * RCS: @(#) $Id: tclProc.c,v 1.96 2006/10/23 21:36:55 msofer Exp $
  */
 
 #include "tclInt.h"
@@ -604,7 +604,7 @@ TclGetFrame(
      */
 
     result = 1;
-    curLevel = (iPtr->varFramePtr == NULL) ? 0 : iPtr->varFramePtr->level;
+    curLevel = iPtr->varFramePtr->level;
     if (*name== '#') {
 	if (Tcl_GetInt(interp, name+1, &level) != TCL_OK || level < 0) {
 	    goto levelError;
@@ -623,19 +623,16 @@ TclGetFrame(
      * Figure out which frame to use, and return it to the caller.
      */
 
-    if (level == 0) {
-	framePtr = NULL;
-    } else {
-	for (framePtr = iPtr->varFramePtr; framePtr != NULL;
-		framePtr = framePtr->callerVarPtr) {
-	    if (framePtr->level == level) {
-		break;
-	    }
-	}
-	if (framePtr == NULL) {
-	    goto levelError;
+    for (framePtr = iPtr->varFramePtr; framePtr != NULL;
+	 framePtr = framePtr->callerVarPtr) {
+	if (framePtr->level == level) {
+	    break;
 	}
     }
+    if (framePtr == NULL) {
+	goto levelError;
+    }
+    
     *framePtrPtr = framePtr;
     return result;
 
@@ -687,7 +684,7 @@ TclObjGetFrame(
      */
 
     result = 1;
-    curLevel = (iPtr->varFramePtr == NULL) ? 0 : iPtr->varFramePtr->level;
+    curLevel = iPtr->varFramePtr->level;
     if (objPtr->typePtr == &levelReferenceType) {
 	if ((int) objPtr->internalRep.twoPtrValue.ptr1) {
 	    level = curLevel - (int) objPtr->internalRep.twoPtrValue.ptr2;
@@ -753,19 +750,15 @@ TclObjGetFrame(
      * Figure out which frame to use, and return it to the caller.
      */
 
-    if (level == 0) {
-	framePtr = NULL;
-    } else {
-	for (framePtr = iPtr->varFramePtr; framePtr != NULL;
-		framePtr = framePtr->callerVarPtr) {
-	    if (framePtr->level == level) {
-		break;
-	    }
-	}
-	if (framePtr == NULL) {
-	    goto levelError;
+    for (framePtr = iPtr->varFramePtr; framePtr != NULL;
+	 framePtr = framePtr->callerVarPtr) {
+	if (framePtr->level == level) {
+	    break;
 	}
     }
+    if (framePtr == NULL) {
+	goto levelError;
+    }
     *framePtrPtr = framePtr;
     return result;