master 011fa3a4cb: Correct implementation of extended frame synchronization

[Po Lu]

branch: master
commit 011fa3a4cb6407603f3a77511977b9563f3438ba
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Correct implementation of extended frame synchronization
    
    * src/xterm.c (handle_one_xevent): Use value provided in the
    extended synchronization message as the current counter value.
---
 src/xterm.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/xterm.c b/src/xterm.c
index 167e3a44d2..d3d8dc468c 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -9139,7 +9139,11 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                        FRAME_X_OUTPUT (f)->sync_end_pending_p = true;
                      }
                    else if (event->xclient.data.l[4] == 1)
-                     FRAME_X_OUTPUT (f)->ext_sync_end_pending_p = true;
+                     {
+                       XSyncIntsToValue (&FRAME_X_OUTPUT 
(f)->current_extended_counter_value,
+                                         event->xclient.data.l[2], 
event->xclient.data.l[3]);
+                       FRAME_X_OUTPUT (f)->ext_sync_end_pending_p = true;
+                     }
 
                    *finish = X_EVENT_DROP;
                    goto done;