Remove the write handler only if there are no longer objects in the output...

Remove the write handler only if there are no longer objects in the output queue AND if the static buffer is empty. This bug was the cause of a possible server-stop-responding-to-client bug under some specific work load. Thanks to Pieter Noordhuis for spotting and fixing it.

src/networking.c

@@ -611,7 +611,7 @@ void sendReplyToClient(aeEventLoop *el, int fd, void *privdata, int mask) {
         }
     }
     if (totwritten > 0) c->lastinteraction = time(NULL);
-    if (listLength(c->reply) == 0) {
+    if (c->bufpos == 0 && listLength(c->reply) == 0) {
         c->sentlen = 0;
         aeDeleteFileEvent(server.el,c->fd,AE_WRITABLE);