Index: generic/tkError.c
==================================================================
--- generic/tkError.c
+++ generic/tkError.c
@@ -163,10 +163,17 @@
      * reduces the overhead of scanning the list to clean up (particularly if
      * there are many handlers that stay around forever).
      */
 
     dispPtr->deleteCount += 1;
+
+    /*
+     * Ensure that no user callback for this handler is invoked any further.
+     */
+
+    errorPtr->errorProc = NULL;
+
     if (dispPtr->deleteCount >= 10) {
 	TkErrorHandler *prevPtr;
 	TkErrorHandler *nextPtr;
 	int lastSerial = LastKnownRequestProcessed(dispPtr->display);
 

Index: unix/tkUnixRFont.c
==================================================================
--- unix/tkUnixRFont.c
+++ unix/tkUnixRFont.c
@@ -776,11 +776,12 @@
 
 	if (!errorFlag) {
 	    LOCK;
 	    XftTextExtents32(fontPtr->display, ftFont, &c, 1, &extents);
 	    UNLOCK;
-	} else {
+	}
+	if (errorFlag) {
 	    extents.xOff = 0;
 	    errorFlag = 0;
 	}
 
 	newX = curX + extents.xOff;