Use local instead of a trip to memory.

src/xt_request.c

@@ -66,10 +66,11 @@ void xt_request_wait(Xt_request *request) {
 
 void xt_request_test(Xt_request *request, int *flag) {
   assert(request);
-  if (*request != XT_REQUEST_NULL) {
-    *flag = (*request)->vtable->test(*request);
-    if (*flag) *request = XT_REQUEST_NULL;
-  } else {
-    *flag = 1;
+  int flag_ = 1;
+  Xt_request req = *request;
+  if (req != XT_REQUEST_NULL) {
+    flag_ = req->vtable->test(req);
+    if (flag_) *request = XT_REQUEST_NULL;
   }
+  *flag = flag_;
 }