[glib] gio: Always purge kqueue subs from missing list

[Philip Withnall <pwithnall src gnome org>]

commit e305fe971e4647d971428a772b7290b9c308a96f
Author: Steven McDonald <steven steven-mcdonald id au>
Date:   Sun Feb 12 11:02:55 2017 +1100

    gio: Always purge kqueue subs from missing list
    
    Previously, _kh_cancel_sub assumed that it only needed to call
    _km_remove if sub did not exist in subs_hash_table. This is erroneous
    because the complementary operation, _km_add_missing, can be called
    from process_kqueue_notifications, in which context sub can *only* have
    come from subs_hash_table.
    
    Since _km_remove is implemented using g_slist_remove, which is
    documented to be a noop if the list does not contain the element to be
    removed, it is safe to call _km_remove unconditionally here.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=778515

 gio/kqueue/kqueue-helper.c |   15 +++++----------
 1 files changed, 5 insertions(+), 10 deletions(-)
---
diff --git a/gio/kqueue/kqueue-helper.c b/gio/kqueue/kqueue-helper.c
index 4671396..d4e66cd 100644
--- a/gio/kqueue/kqueue-helper.c
+++ b/gio/kqueue/kqueue-helper.c
@@ -498,22 +498,17 @@ _kh_add_sub (kqueue_sub *sub)
 gboolean
 _kh_cancel_sub (kqueue_sub *sub)
 {
-  gboolean missing = FALSE;
+  gboolean removed = FALSE;
   g_assert (kqueue_socket_pair[0] != -1);
   g_assert (sub != NULL);
 
+  _km_remove (sub);
+
   G_LOCK (hash_lock);
-  missing = !g_hash_table_remove (subs_hash_table, GINT_TO_POINTER (sub->fd));
+  removed = g_hash_table_remove (subs_hash_table, GINT_TO_POINTER (sub->fd));
   G_UNLOCK (hash_lock);
 
-  if (missing)
-    {
-      /* If there were no fd for this subscription, file is still
-       * missing. */
-      KH_W ("Removing subscription from missing");
-      _km_remove (sub);
-    }
-  else
+  if (removed)
     {
       /* fd will be closed in the kqueue thread */
       _kqueue_thread_remove_fd (sub->fd);