Bug 428680: Sometimes, the document node is the event target for mousemove events now, patch by Matthew Gregan <kinetik@flim.org>, r=smaug, sr=roc, a=damon

content/events/src/nsEventStateManager.cpp

@@ -833,10 +833,11 @@ nsEventStateManager::PreHandleEvent(nsPresContext* aPresContext,
     {
       nsMouseEvent* mouseEvent = static_cast<nsMouseEvent*>(aEvent);
       if (mouseEvent->exit != nsMouseEvent::eTopLevel) {
-        // treat it as a move so we don't generate spurious "exit"
-        // events Any necessary exit events will be generated by
-        // GenerateMouseEnterExit
-        aEvent->message = NS_MOUSE_MOVE;
+        // Treat it as a synthetic move so we don't generate spurious
+        // "exit" or "move" events.  Any necessary "out" or "over" events
+        // will be generated by GenerateMouseEnterExit
+        mouseEvent->message = NS_MOUSE_MOVE;
+        mouseEvent->reason = nsMouseEvent::eSynthesized;
         // then fall through...
       } else {
         GenerateMouseEnterExit((nsGUIEvent*)aEvent);

widget/src/windows/nsWindow.cpp

@@ -5740,7 +5740,15 @@ static PRBool IsTopLevelMouseExit(HWND aWnd)
   POINT mp;
   mp.x = GET_X_LPARAM(pos);
   mp.y = GET_Y_LPARAM(pos);
-  HWND mouseTopLevel = nsWindow::GetTopLevelHWND(::WindowFromPoint(mp));
+  HWND mouseWnd = ::WindowFromPoint(mp);
+
+  // GetTopLevelHWND will return a HWND for the window frame (which includes
+  // the non-client area).  If the mouse has moved into the non-client area,
+  // we should treat it as a top-level exit.
+  HWND mouseTopLevel = nsWindow::GetTopLevelHWND(mouseWnd, false);
+  if (mouseWnd == mouseTopLevel)
+    return PR_TRUE;
+
   return nsWindow::GetTopLevelHWND(aWnd) != mouseTopLevel;
 }