Change X11 error handler override to allow easy X11 error checking.

ui/base/x/x11_util.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file defines utility functions for X11 (Linux only). This code has been
 // ported from XCB since we can't use XCB on Ubuntu while its 32-bit support
 // remains woefully incomplete.
 
 #include "ui/base/x/x11_util.h"
 
@@ skipping 38 matching lines @@
 CachedPictFormats* get_cached_pict_formats() {
   static CachedPictFormats* formats = NULL;
   if (!formats)
     formats = new CachedPictFormats();
   return formats;
 }
 
 // Maximum number of CachedPictFormats we keep around.
 const size_t kMaxCacheSize = 5;
 
+XErrorHandler error_handler_ = NULL;

[Ami GONE FROM CHROMIUM, 2011/09/14 17:11:13]

file-statics don't get trailing underscores (here and below).
(will require renaming either these or the args to the new ctor below)

[dominich, 2011/09/14 19:55:06]

Done.

+XIOErrorHandler io_error_handler_ = NULL;
+
 int DefaultX11ErrorHandler(Display* d, XErrorEvent* e) {
   MessageLoop::current()->PostTask(
        FROM_HERE, NewRunnableFunction(LogErrorEventDescription, d, *e));
   return 0;
 }
 
 int DefaultX11IOErrorHandler(Display* d) {
   // If there's an IO error it likely means the X server has gone away
   LOG(ERROR) << "X IO Error detected";
   _exit(1);
@@ skipping 712 matching lines @@
     // always blowing away the cache. If we are, then we should figure out why
     // and make it bigger.
     NOTREACHED();
   }
 
   return pictformat;
 }
 
 void SetX11ErrorHandlers(XErrorHandler error_handler,
                          XIOErrorHandler io_error_handler) {
-  XSetErrorHandler(error_handler ? error_handler : DefaultX11ErrorHandler);
-  XSetIOErrorHandler(
-      io_error_handler ? io_error_handler : DefaultX11IOErrorHandler);
+  error_handler_ = error_handler ? error_handler : DefaultX11ErrorHandler;
+  io_error_handler_ = io_error_handler ?
+      io_error_handler : DefaultX11IOErrorHandler;
+  XSetErrorHandler(error_handler_);
+  XSetIOErrorHandler(io_error_handler_);
 }
 
 void LogErrorEventDescription(Display* dpy,
                               const XErrorEvent& error_event) {
   char error_str[256];
   char request_str[256];
 
   XGetErrorText(dpy, error_event.error_code, error_str, sizeof(error_str));
 
   strncpy(request_str, "Unknown", sizeof(request_str));
@@ skipping 24 matching lines @@
   LOG(ERROR) 
       << "X Error detected: "
       << "serial " << error_event.serial << ", "
       << "error_code " << static_cast<int>(error_event.error_code)
       << " (" << error_str << "), "
       << "request_code " << static_cast<int>(error_event.request_code) << ", "
       << "minor_code " << static_cast<int>(error_event.minor_code)
       << " (" << request_str << ")";
 }
 
+ScopedX11ErrorHandlerOverride::ScopedX11ErrorHandlerOverride(
+    XErrorHandler error_handler, XIOErrorHandler io_error_handler)
+    : old_error_handler_(error_handler_),
+      old_io_error_handler_(io_error_handler_) {
+  ui::SetX11ErrorHandlers(error_handler, io_error_handler);

[Ami GONE FROM CHROMIUM, 2011/09/14 17:11:13]

ui:: here and below unnecessary?

[Ami GONE FROM CHROMIUM, 2011/09/14 17:11:13]

I expected sync calls here and in the dtor.

[dominich, 2011/09/14 19:55:06]

Done.

[dominich, 2011/09/14 19:55:06]

Done.

+}
+
+ScopedX11ErrorHandlerOverride::~ScopedX11ErrorHandlerOverride() {
+  ui::SetX11ErrorHandlers(old_error_handler_, old_io_error_handler_);
+}
+
 // ----------------------------------------------------------------------------
 // End of x11_util_internal.h
 
 
 }  // namespace ui