Prevented connecting drag drop events to a SwappedOut RenderViewHost in WebContentsViewGtk

content/browser/web_contents/web_drag_dest_gtk.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/web_contents/web_drag_dest_gtk.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
@@ skipping 40 matching lines @@
       widget_(widget),
       context_(NULL),
       data_requests_(0),
       delegate_(NULL),
       method_factory_(this) {
   gtk_drag_dest_set(widget, static_cast<GtkDestDefaults>(0),
                     NULL, 0,
                     static_cast<GdkDragAction>(GDK_ACTION_COPY |
                                                GDK_ACTION_LINK |
                                                GDK_ACTION_MOVE));
-  g_signal_connect(widget, "drag-motion",
-                   G_CALLBACK(OnDragMotionThunk), this);
-  g_signal_connect(widget, "drag-leave",
-                   G_CALLBACK(OnDragLeaveThunk), this);
-  g_signal_connect(widget, "drag-drop",
-                   G_CALLBACK(OnDragDropThunk), this);
-  g_signal_connect(widget, "drag-data-received",
-                   G_CALLBACK(OnDragDataReceivedThunk), this);
+
+  // If adding a handler, make sure to also update the number of handlers in
+  // ~WebDragDestGtk.
+  handlers_.reset(new int[5]);

[Charlie Reis, 2013/03/14 22:08:38]

Magic numbers aren't good.  Better to declare a kNumHandlers constant (just
above GetModifierFlags) and add a DCHECK_EQ(kNumHandlers, handlers_.size())
after you've put them all in.

[mthiesse, 2013/03/15 15:26:49]

Done.

+  handlers_.get()[0] = g_signal_connect(
+      widget, "drag-motion", G_CALLBACK(OnDragMotionThunk), this);
+  handlers_.get()[1] = g_signal_connect(
+      widget, "drag-leave", G_CALLBACK(OnDragLeaveThunk), this);
+  handlers_.get()[2] = g_signal_connect(
+      widget, "drag-drop", G_CALLBACK(OnDragDropThunk), this);
+  handlers_.get()[3] = g_signal_connect(
+      widget, "drag-data-received", G_CALLBACK(OnDragDataReceivedThunk), this);
   // TODO(tony): Need a drag-data-delete handler for moving content out of
   // the WebContents.  http://crbug.com/38989
 
-  destroy_handler_ = g_signal_connect(
+  handlers_.get()[4] = g_signal_connect(
       widget, "destroy", G_CALLBACK(gtk_widget_destroyed), &widget_);
 }
 
 WebDragDestGtk::~WebDragDestGtk() {
   if (widget_) {
     gtk_drag_dest_unset(widget_);
-    g_signal_handler_disconnect(widget_, destroy_handler_);
+    for (int i = 0; i < 5; ++i)
+      g_signal_handler_disconnect(widget_, handlers_.get()[i]);
   }
 }
 
 void WebDragDestGtk::UpdateDragStatus(WebDragOperation operation) {
   if (context_) {
     is_drop_target_ = operation != WebDragOperationNone;
     gdk_drag_status(context_, WebDragOpToGdkDragAction(operation),
                     drag_over_time_);
   }
 }
@@ skipping 211 matching lines @@
   gtk_drag_finish(context, is_drop_target_, FALSE, time);
 
   return TRUE;
 }
 
 RenderViewHostImpl* WebDragDestGtk::GetRenderViewHost() const {
   return static_cast<RenderViewHostImpl*>(web_contents_->GetRenderViewHost());
 }
 
 }  // namespace content