--- libx11-1.6.4/src/Xxcbint.h
+++ libx11-1.6.4-new/src/Xxcbint.h
@@ -27,6 +27,7 @@
 	PendingRequest *pending_requests;
 	PendingRequest *pending_requests_tail;
 	xcb_generic_event_t *next_event;
+	void *next_response;    
 	char *real_bufmax;
 	char *reply_data;
 	int reply_length;
--- libx11-1.6.4/src/xcb_io.c
+++ libx11-1.6.4-new/src/xcb_io.c
@@ -205,8 +205,7 @@
  */
 static void widen(uint64_t *wide, unsigned int narrow)
 {
-	uint64_t new = (*wide & ~((uint64_t)0xFFFFFFFFUL)) | narrow;
-	*wide = new + (((uint64_t)(new < *wide)) << 32);
+	*wide += (int32_t) (narrow - *wide);
 }
 
 /* Thread-safety rules:
@@ -270,13 +269,46 @@
 {
 	void *response;
 	xcb_generic_error_t *error;
+	xcb_generic_reply_t *event;
 	PendingRequest *req;
 	while(!(response = poll_for_event(dpy)) &&
 	      (req = dpy->xcb->pending_requests) &&
-	      !req->reply_waiter &&
-	      xcb_poll_for_reply64(dpy->xcb->connection, req->sequence, &response, &error))
-	{
-		uint64_t request = X_DPY_GET_REQUEST(dpy);
+	      !req->reply_waiter)
+	{
+		uint64_t request;
+
+		/* xcb_poll_for_reply64 could not set error */
+		error = NULL;
+
+		/* return next pending response relative to req */
+		if(dpy->xcb->next_response)
+		{
+			response = dpy->xcb->next_response;
+			dpy->xcb->next_response = NULL;
+			if (((xcb_generic_reply_t*)response)->response_type == X_Error)
+			{
+				error = response;
+				response = NULL;
+			}
+		}
+		else if (!xcb_poll_for_reply64(dpy->xcb->connection, req->sequence,
+					       &response, &error)) {
+			/* xcb_poll_for_reply64 may have read events even if
+			 * there is no reply. */
+			response = poll_for_event(dpy);
+			break;
+		}
+
+		/* xcb_poll_for_reply64 may have read events */
+		event = poll_for_event(dpy);
+		if(event)
+		{
+			dpy->xcb->next_response = error ? error : response;
+			response = event;
+			break;
+		}
+
+		request = X_DPY_GET_REQUEST(dpy);
 		if(XLIB_SEQUENCE_COMPARE(req->sequence, >, request))
 		{
 			throw_thread_fail_assert("Unknown sequence number "