Tests and fix for similar issues in [menu].

3 files changed, 53 insertions, 8 deletions

diff --git a/generic/tkMenu.c b/generic/tkMenu.c
index 42ddbd5..d7f5858 100644
--- a/generic/tkMenu.c
+++ b/generic/tkMenu.c
@@ -2486,9 +2486,10 @@ MenuVarProc(
     const char *value;
     const char *name, *onValue;
 
-    if (flags & TCL_INTERP_DESTROYED) {
+    if (Tcl_InterpDeleted(interp) || (mePtr->namePtr == NULL)) {
 	/*
-	 * Do nothing if the interpreter is going away.
+	 * Do nothing if the interpreter is going away or we have
+	 * no variable name.
 	 */
 
     	return NULL;
@@ -2507,12 +2508,29 @@ MenuVarProc(
      */
 
     if (flags & TCL_TRACE_UNSETS) {
+        ClientData probe = NULL;
 	mePtr->entryFlags &= ~ENTRY_SELECTED;
-	if (flags & TCL_TRACE_DESTROYED) {
-	    Tcl_TraceVar2(interp, name, NULL,
-		    TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
-		    MenuVarProc, clientData);
-	}
+
+        do {
+                probe = Tcl_VarTraceInfo(interp, name,
+                        TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+                        MenuVarProc, probe);
+                if (probe == (ClientData)mePtr) {
+                    break;
+                }
+        } while (probe);
+        if (probe) {
+                /* 
+                 * We were able to fetch the unset trace for our
+                 * namePtr, which means it is not unset and not
+                 * the cause of this unset trace. Instead some outdated
+                 * former variable must be, and we should ignore it.
+                 */
+		return NULL;
+        }
+	Tcl_TraceVar2(interp, name, NULL,
+		TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		MenuVarProc, clientData);
 	TkpConfigureMenuEntry(mePtr);
 	TkEventuallyRedrawMenu(menuPtr, NULL);
 	return NULL;
diff --git a/generic/tkScale.c b/generic/tkScale.c
index 3920aea..4630170 100644
--- a/generic/tkScale.c
+++ b/generic/tkScale.c
@@ -1198,7 +1198,6 @@ ScaleVarProc(
      */
 
     if (flags & TCL_TRACE_UNSETS) {
-
         if (!Tcl_InterpDeleted(interp) && scalePtr->varNamePtr) {
             ClientData probe = NULL;
 
diff --git a/tests/menu.test b/tests/menu.test
index 95699ff..9378686 100644
--- a/tests/menu.test
+++ b/tests/menu.test
@@ -3162,6 +3162,34 @@ test menu-17.5 {MenuVarProc} -setup {
 } -cleanup {
 	deleteWindows
 } -result {{} goodbye {}}
+test menu-17.6 {MenuVarProc [5d991b822e]} -setup {
+	deleteWindows
+} -body {
+    # Want this not to crash
+    menu .b
+    set var INIT
+    .b add checkbutton -variable var
+    trace add variable var unset {apply {args {
+        .b entryconfigure 1 -variable {}
+    }}}
+    unset var
+} -cleanup {
+	deleteWindows
+} -result {}
+test menu-17.7 {MenuVarProc [5d991b822e]} -setup {
+	deleteWindows
+} -body {
+    # Want this not to duplicate traces
+    menu .b
+    set var INIT
+    .b add checkbutton -variable var
+    trace add variable var unset {apply {args {
+        .b entryconfigure 1 -variable new
+    }}}
+    unset var
+} -cleanup {
+	deleteWindows
+} -result {}
 
 
 test menu-18.1 {TkActivateMenuEntry} -setup {