File b_sync-fix.patch of Package xorg-x11-server.16372

Index: xorg-server-1.12.1/Xext/sync.c
===================================================================
--- xorg-server-1.12.1.orig/Xext/sync.c
+++ xorg-server-1.12.1/Xext/sync.c
@@ -2615,9 +2615,43 @@ static XSyncValue *pIdleTimeValueGreater
 static void
 IdleTimeQueryValue(pointer pCounter, CARD64 * pValue_return)
 {
-    CARD32 idle = GetTimeInMillis() - lastDeviceEventTime.milliseconds;
+    static CARD32 previousLastDeviceEventTimeMilliseconds = 0;
+    CARD32        now              = GetTimeInMillis();
+    CARD32        idle             = now - lastDeviceEventTime.milliseconds;
+    CARD32        previousIdle     = now - previousLastDeviceEventTimeMilliseconds;
+    SyncCounter  *pIdleTimeCounter = (SyncCounter*)pCounter;
 
     XSyncIntsToValue(pValue_return, idle, 0);
+    if (pCounter == NULL)
+    {
+        return;
+    }
+    if (previousLastDeviceEventTimeMilliseconds == 0)
+    {
+        /* initialize static var when this function is invoked the first time. */
+        previousLastDeviceEventTimeMilliseconds = lastDeviceEventTime.milliseconds;
+        return;
+    }
+
+    if (previousLastDeviceEventTimeMilliseconds == lastDeviceEventTime.milliseconds)
+    {
+        /* no new user event, no need to change idle counter. */
+        return;
+    }
+   previousLastDeviceEventTimeMilliseconds = lastDeviceEventTime.milliseconds;
+
+    /*
+     * Some user event occured; now update idle counter with previous
+     * event time, so idle counter has the most up-to-date value with
+     * respect to previous user event (we need old and new counter
+     * value to compute if a transition occured).  Recompute bracket
+     * values if this is system counter.
+     */
+
+    XSyncIntsToValue  (&pIdleTimeCounter->value, previousIdle, 0);
+    if (IsSystemCounter(pIdleTimeCounter)) {
+        SyncComputeBracketValues(pIdleTimeCounter);
+    }
 }
 
 static void
@@ -2700,7 +2734,7 @@ IdleTimeWakeupHandler(pointer env, int r
     if (!pIdleTimeValueLess && !pIdleTimeValueGreater)
         return;
 
-    IdleTimeQueryValue(NULL, &idle);
+    IdleTimeQueryValue(IdleTimeCounter, &idle);
 
     if ((pIdleTimeValueGreater &&
          XSyncValueGreaterOrEqual(idle, *pIdleTimeValueGreater)) ||