In fullscreen mode, the window property of cocoaView may not be the key
window, and the current implementation would not grab mouse in fullscreen
mode after user ungrabs cursor in fullscreen mode with hot-key, and left
clicks the relative input devices to re-grab it.

This patch used value of isFullscreen as a short-cirtuit condition for
relative input device grabbing.

Signed-off-by: Chen Zhang <tgfbeta@me.com>
---
 ui/cocoa.m | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/ui/cocoa.m b/ui/cocoa.m
index 474d44cb9f..aa7cf07368 100644
--- a/ui/cocoa.m
+++ b/ui/cocoa.m
@@ -901,7 +901,12 @@ QemuCocoaView *cocoaView;
         case NSEventTypeLeftMouseUp:
             mouse_event = true;
             if (!isMouseGrabbed && [self screenContainsPoint:p]) {
-                if([[self window] isKeyWindow]) {
+                /*
+                 * In fullscreen mode, the window of cocoaView may not be the
+                 * key window, therefore the position relative to the virtual
+                 * screen alone will be sufficient.
+                 */
+                if(isFullscreen || [[self window] isKeyWindow]) {
                     [self grabMouse];
                 }
             }
-- 
2.19.2