[PATCH resend] winex11.drv: Try harder to grab pointer.

[Zhiyi Zhang]

Some window managers temporarily grab the pointer during window transition.
We need to wait a while for window manager to release its grab, otherwise
XGrabPointer may fail with AlreadyGrabbed, causing cursor clipping to fail.

Signed-off-by: Zhiyi Zhang 
---
 dlls/winex11.drv/mouse.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/dlls/winex11.drv/mouse.c b/dlls/winex11.drv/mouse.c
index f737a306a5..7501959369 100644
--- a/dlls/winex11.drv/mouse.c
+++ b/dlls/winex11.drv/mouse.c
@@ -378,9 +378,13 @@ static BOOL grab_clipping_window( const RECT *clip )
 {
     static const WCHAR messageW[] = {'M','e','s','s','a','g','e',0};
     struct x11drv_thread_data *data = x11drv_thread_data();
+    static DWORD timeout = 5000;
+    static DWORD step = 100;
+    DWORD time = 0;
     Window clip_window;
     HWND msg_hwnd = 0;
     POINT pos;
+    INT ret;

if (GetWindowThreadProcessId( GetDesktopWindow(), NULL ) == GetCurrentThreadId())
         return TRUE;  /* don't clip in the desktop process */
@@ -416,13 +420,24 @@ static BOOL grab_clipping_window( const RECT *clip )
         clip->right < clip_rect.right || clip->bottom < clip_rect.bottom)
         data->warp_serial = NextRequest( data->display );

-    if (!XGrabPointer( data->display, clip_window, False,
-                       PointerMotionMask | ButtonPressMask | ButtonReleaseMask,
-                       GrabModeAsync, GrabModeAsync, clip_window, None, CurrentTime ))
+    /* Some windows managers temporarily grab the pointer during window transition. Retry grabbing. */
+    do
+    {
+        ret = XGrabPointer( data->display, clip_window, False, PointerMotionMask | ButtonPressMask | ButtonReleaseMask,
+                            GrabModeAsync, GrabModeAsync, clip_window, None, CurrentTime );
+        if (ret == AlreadyGrabbed || ret == GrabFrozen)
+        {
+            time += step;
+            Sleep(step);
+        }
+    } while ((ret == AlreadyGrabbed || ret == GrabFrozen) && time < timeout);
+
+    if (ret == GrabSuccess)
         clipping_cursor = TRUE;

if (!clipping_cursor)
     {
+        ERR("Failed to grab pointer\n");
         disable_xinput2();
         DestroyWindow( msg_hwnd );
         return FALSE;