Fix bug #16766. This should fix the requirement to release the mouse before context menus work. r=pavlov, sr=blizzard. Patch from Kevin Buhr <buhr@stat.wisc.edu>. Thanks.

widget/src/gtk/nsWidget.cpp

@@ -118,18 +118,6 @@ void nsWidget::GetLastEventTime(guint32 *aTime)
     *aTime = sLastEventTime;
 }
 
-void nsWidget::DragStarted(void)
-{
-  if (sButtonMotionTarget)
-  {
-    sButtonMotionTarget = nsnull;
-    sButtonMotionRootX = -1;
-    sButtonMotionRootY = -1;
-    sButtonMotionWidgetX = -1;
-    sButtonMotionWidgetY = -1;
-  }
-}
-
 #ifdef USE_XIM
 nsresult nsWidget::KillICSpotTimer ()
 {
@@ -409,7 +397,7 @@ NS_IMETHODIMP nsWidget::Destroy(void)
 
   // we don't want people sending us events if we are the button motion target
   if (sButtonMotionTarget == this)
-    sButtonMotionTarget = nsnull;
+    DropMotionTarget();
 
   // ok, set our state
   mIsDestroying = PR_TRUE;
@@ -1757,7 +1745,7 @@ nsWidget::OnEnterNotifySignal(GdkEventCrossing * aGdkCrossingEvent)
   //
   // XXX ramiro - Same as above.
   //
-  if (sButtonMotionTarget)
+  if (nsnull != sButtonMotionTarget)
   {
     return;
   }
@@ -2051,14 +2039,7 @@ nsWidget::OnButtonReleaseSignal(GdkEventButton * aGdkButtonEvent)
   theWidget->DispatchMouseEvent(event);
   NS_IF_RELEASE(theWidget);
 
-
-  if (sButtonMotionTarget)
-  {
-    sButtonMotionTarget = nsnull;
-
-    sButtonMotionRootX = -1;
-    sButtonMotionRootY = -1;
-  }
+  DropMotionTarget();
 }
 //////////////////////////////////////////////////////////////////////
 /* virtual */ void

widget/src/gtk/nsWidget.h

@@ -206,9 +206,11 @@ public:
   static void SetLastEventTime(guint32 aTime);
   static void GetLastEventTime(guint32 *aTime);
 
+  static void DropMotionTarget(void) { sButtonMotionTarget = nsnull; };
+
   // inform the widget code that we are about to do a drag - it must
   // release the sButtonMotionTarget if it is set.
-  static void DragStarted(void);
+  static void DragStarted(void) { DropMotionTarget(); };
 
 protected:
 

widget/src/gtk/nsWindow.cpp

@@ -821,6 +821,7 @@ void nsWindow::NativeGrab(PRBool aGrab)
   if (aGrab) {
     GdkCursor *cursor = gdk_cursor_new (GDK_ARROW);
     
+    DropMotionTarget();
     gint retval;
     retval = gdk_pointer_grab (GDK_SUPERWIN(mSuperWin)->bin_window, PR_TRUE,(GdkEventMask)
                                (GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
@@ -853,6 +854,7 @@ void nsWindow::NativeGrab(PRBool aGrab)
     printf("nsWindow::NativeGrab %p ungrab\n", this);
 #endif
     gdk_keyboard_ungrab(GDK_CURRENT_TIME);
+    DropMotionTarget();
     gdk_pointer_ungrab(GDK_CURRENT_TIME);
   }
 }
@@ -2421,7 +2423,13 @@ NS_IMETHODIMP nsWindow::CaptureMouse(PRBool aCapture)
 
   if (aCapture)
   {
+    if (!grabWidget) {
+      g_print("nsWindow::CaptureMouse on NULL grabWidget\n");
+      return NS_ERROR_FAILURE;
+    }
+
     GdkCursor *cursor = gdk_cursor_new (GDK_ARROW);
+    DropMotionTarget();
     gdk_pointer_grab (GTK_WIDGET(grabWidget)->window, PR_TRUE,(GdkEventMask)
                       (GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
                        GDK_ENTER_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK |
@@ -2432,8 +2440,9 @@ NS_IMETHODIMP nsWindow::CaptureMouse(PRBool aCapture)
   }
   else
   {
+    DropMotionTarget();
     gdk_pointer_ungrab(GDK_CURRENT_TIME);
-    gtk_grab_remove(grabWidget);
+    if (grabWidget) gtk_grab_remove(grabWidget);
   }
 
   return NS_OK;