Latest fix proposal from Christian Werner: revert the two previous commits and add XSync() just before the garbage collector, which minimizes the number of XSync() calls, therefore optimizing performance while still fixing the bug.

1 files changed, 18 insertions, 10 deletions

diff --git a/generic/tkError.c b/generic/tkError.c
index fc223e6..277d7f0 100644
--- a/generic/tkError.c
+++ b/generic/tkError.c
@@ -82,8 +82,8 @@ Tk_CreateErrorHandler(
 				 * errors. */
     ClientData clientData)	/* Arbitrary value to pass to errorProc. */
 {
-    register TkErrorHandler *errorPtr;
-    register TkDisplay *dispPtr;
+    TkErrorHandler *errorPtr;
+    TkDisplay *dispPtr;
 
     /*
      * Find the display. If Tk doesn't know about this display then it's an
@@ -147,8 +147,8 @@ Tk_DeleteErrorHandler(
     Tk_ErrorHandler handler)	/* Token for handler to delete; was previous
 				 * return value from Tk_CreateErrorHandler. */
 {
-    register TkErrorHandler *errorPtr = (TkErrorHandler *) handler;
-    register TkDisplay *dispPtr = errorPtr->dispPtr;
+    TkErrorHandler *errorPtr = (TkErrorHandler *) handler;
+    TkDisplay *dispPtr = errorPtr->dispPtr;
 
     errorPtr->lastRequest = NextRequest(dispPtr->display) - 1;
 
@@ -166,12 +166,20 @@ Tk_DeleteErrorHandler(
 
     dispPtr->deleteCount += 1;
     if (dispPtr->deleteCount >= 10) {
-	register TkErrorHandler *prevPtr;
+	TkErrorHandler *prevPtr;
 	TkErrorHandler *nextPtr;
-	int lastSerial;
+	int lastSerial = LastKnownRequestProcessed(dispPtr->display);
 
+	/*
+	 * Last chance to catch errors for this handler: if no event/error
+	 * processing took place to follow up the end of this error handler
+	 * we need a round trip with the X server now.
+	 */
+
+	if (errorPtr->lastRequest > (unsigned long) lastSerial) {
+	    XSync(dispPtr->display, False);
+	}
 	dispPtr->deleteCount = 0;
-	lastSerial = LastKnownRequestProcessed(dispPtr->display);
 	errorPtr = dispPtr->errorPtr;
 	for (prevPtr = NULL; errorPtr != NULL; errorPtr = nextPtr) {
 	    nextPtr = errorPtr->nextPtr;
@@ -213,11 +221,11 @@ Tk_DeleteErrorHandler(
 static int
 ErrorProc(
     Display *display,		/* Display for which error occurred. */
-    register XErrorEvent *errEventPtr)
+    XErrorEvent *errEventPtr)
 				/* Information about error. */
 {
-    register TkDisplay *dispPtr;
-    register TkErrorHandler *errorPtr;
+    TkDisplay *dispPtr;
+    TkErrorHandler *errorPtr;
 
     /*
      * See if we know anything about the display. If not, then invoke the