src/macosx/native/sun/osxapp/NSApplicationAWT.m

*** 339,348 ****
--- 339,352 ----
  - (void)sendEvent:(NSEvent *)event
  {
      if ([event type] == NSApplicationDefined && TS_EQUAL([event timestamp], dummyEventTimestamp)) {
          [seenDummyEventLock lockWhenCondition:NO];
          [seenDummyEventLock unlockWithCondition:YES];
+     } else if ([event type] == NSKeyUp && ([event modifierFlags] & NSCommandKeyMask)) {
+         // Cocoa won't send us key up event when releasing a key while Cmd is down,
+         // so we have to do it ourselves.
+         [[self keyWindow] sendEvent:event];
      } else {
          [super sendEvent:event];
      }
  }