3 files changed, 20 insertions, 13 deletions

diff --git a/xserver/miext/sync/misync.c b/xserver/miext/sync/misync.c
index 490fa0b17..0931803f6 100644
--- a/xserver/miext/sync/misync.c
+++ b/xserver/miext/sync/misync.c
@@ -101,24 +101,29 @@ miSyncInitFence(ScreenPtr pScreen, SyncFence * pFence, Bool initially_triggered)
     pFence->funcs = miSyncFenceFuncs;
 
     pScreenPriv->funcs.CreateFence(pScreen, pFence, initially_triggered);
+
+    pFence->sync.initialized = TRUE;
 }
 
 void
 miSyncDestroyFence(SyncFence * pFence)
 {
-    ScreenPtr pScreen = pFence->pScreen;
-    SyncScreenPrivPtr pScreenPriv = SYNC_SCREEN_PRIV(pScreen);
-    SyncTriggerList *ptl, *pNext;
-
     pFence->sync.beingDestroyed = TRUE;
-    /* tell all the fence's triggers that the counter has been destroyed */
-    for (ptl = pFence->sync.pTriglist; ptl; ptl = pNext) {
-        (*ptl->pTrigger->CounterDestroyed) (ptl->pTrigger);
-        pNext = ptl->next;
-        free(ptl);              /* destroy the trigger list as we go */
-    }
 
-    pScreenPriv->funcs.DestroyFence(pScreen, pFence);
+    if (pFence->sync.initialized) {
+        ScreenPtr pScreen = pFence->pScreen;
+        SyncScreenPrivPtr pScreenPriv = SYNC_SCREEN_PRIV(pScreen);
+        SyncTriggerList *ptl, *pNext;
+
+        /* tell all the fence's triggers that the counter has been destroyed */
+        for (ptl = pFence->sync.pTriglist; ptl; ptl = pNext) {
+            (*ptl->pTrigger->CounterDestroyed) (ptl->pTrigger);
+            pNext = ptl->next;
+            free(ptl); /* destroy the trigger list as we go */
+        }
+
+        pScreenPriv->funcs.DestroyFence(pScreen, pFence);
+    }
 
     dixFreeObjectWithPrivates(pFence, PRIVATE_SYNC_FENCE);
 }
diff --git a/xserver/miext/sync/misync.h b/xserver/miext/sync/misync.h
index dc78c5fdb..f7082d5ea 100644
--- a/xserver/miext/sync/misync.h
+++ b/xserver/miext/sync/misync.h
@@ -28,6 +28,7 @@
 #ifndef _MISYNC_H_
 #define _MISYNC_H_
 
+typedef struct _SyncObject SyncObject;
 typedef struct _SyncFence SyncFence;
 typedef struct _SyncTrigger SyncTrigger;
 
diff --git a/xserver/miext/sync/misyncstr.h b/xserver/miext/sync/misyncstr.h
index 2eab2aa57..6f89714d6 100644
--- a/xserver/miext/sync/misyncstr.h
+++ b/xserver/miext/sync/misyncstr.h
@@ -38,13 +38,14 @@
 #define SYNC_COUNTER		0
 #define SYNC_FENCE		1
 
-typedef struct _SyncObject {
+struct _SyncObject {
     ClientPtr client;           /* Owning client. 0 for system counters */
     struct _SyncTriggerList *pTriglist; /* list of triggers */
     XID id;                     /* resource ID */
     unsigned char type;         /* SYNC_* */
+    unsigned char initialized;  /* FALSE if created but not initialized */
     Bool beingDestroyed;        /* in process of going away */
-} SyncObject;
+};
 
 typedef struct _SyncCounter {
     SyncObject sync;            /* Common sync object data */