From 5dabe448bda68a483bf444a4adfed2b25b30f600 Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter@cs.unisa.edu.au>
Date: Sat, 24 Nov 2007 15:00:43 +1030
Subject: [PATCH] dix: Add special treatment of NotifyUngrab for enter/leave
 events.

In some cases (e.g. using x2x) the previous model broke, with a window ending
not counting down to 0 anymore. Special treatment for NotifyUngrab seems to
help here.

Current solution: If a NotifyGrab is to be sent ignore it. If a NotifyUngrab
enter is sent, only adjust the semaphore if it is on 0. Likewise, do the same
for a NotifyUngrab leave if the semaphore is on 1. This seems to work alright
so far.
---
 dix/events.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/dix/events.c b/dix/events.c
index 88ce50179..123f21f41 100644
--- a/dix/events.c
+++ b/dix/events.c
@@ -4468,15 +4468,20 @@ LeaveNotifies(DeviceIntPtr pDev,
     }
 }
 
+/* welcome to insanity */
 #define FOCUS_SEMAPHORE_MODIFY(win, field, mode, val) \
-    { \
-        if (mode != NotifyGrab && mode != NotifyUngrab) \
-        { \
-            FocusSemaphoresPtr sem;\
-            sem = (FocusSemaphoresPtr)win->devPrivates[FocusPrivatesIndex].ptr; \
+{ \
+    FocusSemaphoresPtr sem;\
+    sem = (FocusSemaphoresPtr)win->devPrivates[FocusPrivatesIndex].ptr; \
+    if (mode != NotifyGrab && mode != NotifyUngrab) { \
+        sem->field += val; \
+    } else if (mode == NotifyUngrab) { \
+        if (sem->field == 0 && val > 0) \
             sem->field += val; \
-        } \
-    }
+        else if (sem->field == 1 && val < 0) \
+            sem->field += val; \
+    } \
+}
 #define ENTER_LEAVE_SEMAPHORE_UP(win, mode)  \
         FOCUS_SEMAPHORE_MODIFY(win, enterleave, mode, 1);