socket: Fix internal_select()

vstinner · vstinner · commit 0cec877230a9 · 2016-07-22T17:26:53.000+02:00
Bug found by Pavel Belikov ("Fragment N1"): http://www.viva64.com/en/b/0414/#ID0ECDAE
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
@@ -648,7 +648,7 @@ internal_select(PySocketSockObject *s, int writing, _PyTime_t interval,
     assert(!(connect && !writing));
 
     /* Guard against closed socket */
-    if (s->sock_fd < 0)
+    if (s->sock_fd == INVALID_SOCKET)
         return 0;
 
     /* Prefer poll, if available, since you can poll() any fd
