[mutter/wip/carlosg/help-cleanup-gtk-usage: 2/2] backends/x11: Flush connection after ungrab

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 45fea572846e86a06367bc0f31fc482206339e43
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon Nov 26 14:32:01 2018 +0100

    backends/x11: Flush connection after ungrab
    
    Modal ungrabs may be followed by other clients trying to grab themselves,
    flush the connection so we ensure the right order of events on the Xserver
    side.
    
    An example of this is js/ui/modalDialog.js in gnome-shell, as the alt-F2
    dialog may launch X11 clients trying to grab themselves, commit a40daa3c22
    in gnome-shell handled the case and added a gdk_display_sync() call to
    ensure no grab existed at the time of executing.
    
    This commit aims to achieve the same built in MetaBackend. A full sync
    seems excessive though, as we just need to make sure the server got the
    messages queued before the other side tries to grab, a XFlush seems
    sufficient for this.

 src/backends/x11/meta-backend-x11.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/backends/x11/meta-backend-x11.c b/src/backends/x11/meta-backend-x11.c
index 99cc6180c..c1c976986 100644
--- a/src/backends/x11/meta-backend-x11.c
+++ b/src/backends/x11/meta-backend-x11.c
@@ -577,6 +577,7 @@ meta_backend_x11_ungrab_device (MetaBackend *backend,
   int ret;
 
   ret = XIUngrabDevice (priv->xdisplay, device_id, timestamp);
+  XFlush (priv->xdisplay);
 
   return (ret == Success);
 }