Backport: Fix for 18993.

* nsterm.m (ns_send_appdefined): Check for application defined
event on Cocoa (Bug#18993).  Backport from trunk.

src/ChangeLog

@@ -1,3 +1,8 @@
+2014-11-15  Jan Djärv  <jan.h.d@swipnet.se>
+
+        * nsterm.m (ns_send_appdefined): Check for application defined
+        event on Cocoa (Bug#18993).  Backport from trunk.
+
 2014-11-15  Eli Zaretskii  <eliz@gnu.org>
 
 	* window.c (window_scroll_pixel_based): Avoid truncation/rounding

src/nsterm.m

@@ -3434,6 +3434,21 @@ overwriting cursor (usually when cursor on a tab) */
   /* Only post this event if we haven't already posted one.  This will end
        the [NXApp run] main loop after having processed all events queued at
        this moment.  */
+
+#ifdef NS_IMPL_COCOA
+  if (! send_appdefined)
+    {
+      /* OSX 10.10.1 swallows the AppDefined event we are sending ourselves
+         in certain situations (rapid incoming events).
+         So check if we have one, if not add one.  */
+      NSEvent *appev = [NSApp nextEventMatchingMask:NSApplicationDefinedMask
+                                          untilDate:[NSDate distantPast]
+                                             inMode:NSDefaultRunLoopMode
+                                            dequeue:NO];
+      if (! appev) send_appdefined = YES;
+    }
+#endif
+
   if (send_appdefined)
     {
       NSEvent *nxev;