Fix [5d991b822e]: segmentation violation in TclObjLookupVarEx. Patch from Christian Werner.

8 files changed, 121 insertions, 8 deletions

diff --git a/generic/tkButton.c b/generic/tkButton.c
index b7e314e..e114a51 100644
--- a/generic/tkButton.c
+++ b/generic/tkButton.c
@@ -1611,6 +1611,19 @@ ButtonVarProc(
     Tcl_Obj *valuePtr;
 
     /*
+     * See ticket [5d991b82].
+     */
+
+    if (butPtr->selVarNamePtr == NULL) {
+	if (!(flags & TCL_INTERP_DESTROYED)) {
+	    Tcl_UntraceVar2(interp, name1, name2,
+		    TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		    ButtonVarProc, clientData);
+	}
+	return NULL;
+    }
+
+    /*
      * If the variable is being unset, then just re-establish the trace unless
      * the whole interpreter is going away.
      */
@@ -1692,8 +1705,8 @@ static char *
 ButtonTextVarProc(
     ClientData clientData,	/* Information about button. */
     Tcl_Interp *interp,		/* Interpreter containing variable. */
-    const char *name1,		/* Not used. */
-    const char *name2,		/* Not used. */
+    const char *name1,		/* Name of variable. */
+    const char *name2,		/* Second part of variable name. */
     int flags)			/* Information about what happened. */
 {
     TkButton *butPtr = clientData;
@@ -1704,6 +1717,19 @@ ButtonTextVarProc(
     }
 
     /*
+     * See ticket [5d991b82].
+     */
+
+    if (butPtr->textVarNamePtr == NULL) {
+	if (!(flags & TCL_INTERP_DESTROYED)) {
+	    Tcl_UntraceVar2(interp, name1, name2,
+		    TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		    ButtonTextVarProc, clientData);
+	}
+ 	return NULL;
+     }
+ 
+    /*
      * If the variable is unset, then immediately recreate it unless the whole
      * interpreter is going away.
      */
diff --git a/generic/tkEntry.c b/generic/tkEntry.c
index 9a2f900..6344df2 100644
--- a/generic/tkEntry.c
+++ b/generic/tkEntry.c
@@ -3137,8 +3137,8 @@ static char *
 EntryTextVarProc(
     ClientData clientData,	/* Information about button. */
     Tcl_Interp *interp,		/* Interpreter containing variable. */
-    const char *name1,		/* Not used. */
-    const char *name2,		/* Not used. */
+    const char *name1,		/* Name of variable. */
+    const char *name2,		/* Second part of variable name. */
     int flags)			/* Information about what happened. */
 {
     Entry *entryPtr = clientData;
@@ -3152,6 +3152,19 @@ EntryTextVarProc(
     }
 
     /*
+     * See ticket [5d991b82].
+     */
+
+    if (entryPtr->textVarName == NULL) {
+	if (!(flags & TCL_INTERP_DESTROYED)) {
+	    Tcl_UntraceVar2(interp, name1, name2,
+		    TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		    EntryTextVarProc, clientData);
+	}
+ 	return NULL;
+     }
+
+    /*
      * If the variable is unset, then immediately recreate it unless the whole
      * interpreter is going away.
      */
diff --git a/generic/tkListbox.c b/generic/tkListbox.c
index b18a7f4..5f650fe 100644
--- a/generic/tkListbox.c
+++ b/generic/tkListbox.c
@@ -3431,8 +3431,8 @@ static char *
 ListboxListVarProc(
     ClientData clientData,	/* Information about button. */
     Tcl_Interp *interp,		/* Interpreter containing variable. */
-    const char *name1,		/* Not used. */
-    const char *name2,		/* Not used. */
+    const char *name1,		/* Name of variable. */
+    const char *name2,		/* Second part of variable name. */
     int flags)			/* Information about what happened. */
 {
     Listbox *listPtr = clientData;
@@ -3441,6 +3441,19 @@ ListboxListVarProc(
     Tcl_HashEntry *entry;
 
     /*
+     * See ticket [5d991b82].
+     */
+
+    if (listPtr->listVarName == NULL) {
+	if (!(flags & TCL_INTERP_DESTROYED)) {
+	    Tcl_UntraceVar2(interp, name1, name2,
+		    TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		    ListboxListVarProc, clientData);
+	}
+	return NULL;
+    }
+
+    /*
      * Bwah hahahaha! Puny mortal, you can't unset a -listvar'd variable!
      */
 
diff --git a/generic/tkMenu.c b/generic/tkMenu.c
index 0dcc1c2..9e6f37a 100644
--- a/generic/tkMenu.c
+++ b/generic/tkMenu.c
@@ -2500,6 +2500,17 @@ MenuVarProc(
     	return NULL;
     }
 
+    /*
+     * See ticket [5d991b82].
+     */
+
+    if (mePtr->namePtr == NULL) {
+	Tcl_UntraceVar2(interp, name1, name2,
+		TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		MenuVarProc, clientData);
+	return NULL;
+     }
+
     name = Tcl_GetString(mePtr->namePtr);
 
     /*
diff --git a/generic/tkMenubutton.c b/generic/tkMenubutton.c
index 1a4d5ae..2c1676c 100644
--- a/generic/tkMenubutton.c
+++ b/generic/tkMenubutton.c
@@ -882,6 +882,19 @@ MenuButtonTextVarProc(
     unsigned len;
 
     /*
+     * See ticket [5d991b82].
+     */
+
+    if (mbPtr->textVarName == NULL) {
+	if (!(flags & TCL_INTERP_DESTROYED)) {
+	    Tcl_UntraceVar2(interp, name1, name2,
+		    TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		    MenuButtonTextVarProc, clientData);
+	}
+	return NULL;
+    }
+
+    /*
      * If the variable is unset, then immediately recreate it unless the whole
      * interpreter is going away.
      */
diff --git a/generic/tkMessage.c b/generic/tkMessage.c
index 2b71998..f65b046 100644
--- a/generic/tkMessage.c
+++ b/generic/tkMessage.c
@@ -839,6 +839,19 @@ MessageTextVarProc(
     const char *value;
 
     /*
+     * See ticket [5d991b82].
+     */
+
+    if (msgPtr->textVarName == NULL) {
+	if (!(flags & TCL_INTERP_DESTROYED)) {
+	    Tcl_UntraceVar2(interp, name1, name2,
+		    TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		    MessageTextVarProc, clientData);
+	}
+	return NULL;
+    }
+
+    /*
      * If the variable is unset, then immediately recreate it unless the whole
      * interpreter is going away.
      */
diff --git a/generic/tkScale.c b/generic/tkScale.c
index ef67630..af45afa 100644
--- a/generic/tkScale.c
+++ b/generic/tkScale.c
@@ -1193,6 +1193,19 @@ ScaleVarProc(
     int result;
 
     /*
+     * See ticket [5d991b82].
+     */
+
+    if (scalePtr->varNamePtr == NULL) {
+	if (!(flags & TCL_INTERP_DESTROYED)) {
+	    Tcl_UntraceVar2(interp, name1, name2,
+		    TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		    ScaleVarProc, clientData);
+	}
+	return NULL;
+    }
+
+    /*
      * If the variable is unset, then immediately recreate it unless the whole
      * interpreter is going away.
      */
diff --git a/generic/ttk/ttkTrace.c b/generic/ttk/ttkTrace.c
index c0f17cf..c8bbdaf 100644
--- a/generic/ttk/ttkTrace.c
+++ b/generic/ttk/ttkTrace.c
@@ -26,8 +26,8 @@ static char *
 VarTraceProc(
     ClientData clientData,	/* Widget record pointer */
     Tcl_Interp *interp, 	/* Interpreter containing variable. */
-    const char *name1,		/* (unused) */
-    const char *name2,		/* (unused) */
+    const char *name1,		/* Name of variable. */
+    const char *name2,		/* Second part of variable name. */
     int flags)			/* Information about what happened. */
 {
     Ttk_TraceHandle *tracePtr = clientData;
@@ -38,6 +38,17 @@ VarTraceProc(
 	return NULL;
     }
 
+    /*
+     * See ticket [5d991b82].
+     */
+
+    if (tracePtr->varnameObj == NULL) {
+	Tcl_UntraceVar2(interp, name1, name2,
+		TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		VarTraceProc, clientData);
+	return NULL;
+    }
+
     name = Tcl_GetString(tracePtr->varnameObj);
 
     /*