Fix a logic bug in kqueue.c.

base/third_party/libevent/kqueue.c

 /*      $OpenBSD: kqueue.c,v 1.5 2002/07/10 14:41:31 art Exp $  */
 
 /*
  * Copyright 2000-2002 Niels Provos <provos@citi.umich.edu>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
@@ skipping 122 matching lines @@
                 free (kqueueop);
                 return (NULL);
         }
         kqueueop->nevents = NEVENT;
 
         /* we need to keep track of multiple events per signal */
         for (i = 0; i < NSIG; ++i) {
                 TAILQ_INIT(&kqueueop->evsigevents[i]);
         }
 
         /* Check for Mac OS X kqueue bug. */

[Mark Mentovai, 2016/07/08 11:15:02]

Since we’ve already got a bunch of local modifications, I’d be just as inclined
to remove this section altogether. It tests for a 10.4 bug that was fixed in
10.5, so it’s just bloat as far as we’re concerned.

[erikchen, 2016/07/08 15:20:06]

Done.

         memset(&kqueueop->changes[0], 0, sizeof kqueueop->changes[0]);
         kqueueop->changes[0].ident = -1;
         kqueueop->changes[0].filter = EVFILT_READ;
         kqueueop->changes[0].flags = EV_ADD;
         /* 
          * If kqueue works, then kevent will succeed, and it will
          * stick an error in events[0].  If kqueue is broken, then
          * kevent will fail.
          */
         if (kevent(kq,
                 kqueueop->changes, 1, kqueueop->events, NEVENT, NULL) != 1 ||
             kqueueop->events[0].ident != -1 ||
-            kqueueop->events[0].flags != EV_ERROR) {
+            !(kqueueop->events[0].flags & EV_ERROR)) {
                 event_warn("%s: detected broken kqueue; not using.", __func__);
                 free(kqueueop->changes);
                 free(kqueueop->events);
                 free(kqueueop);
                 close(kq);
                 return (NULL);
         }
 
         return (kqueueop);
 }
@@ skipping 279 matching lines @@
         if (kqop->changes)
                 free(kqop->changes);
         if (kqop->events)
                 free(kqop->events);
         if (kqop->kq >= 0 && kqop->pid == getpid())
                 close(kqop->kq);
 
         memset(kqop, 0, sizeof(struct kqop));
         free(kqop);
 }