[glib: 4/5] gqueue: Remove a redundant branch

[Sebastian Dröge <sdroege src gnome org>]

commit d5093350f3ea6a28bd02e4ed05466f83eacbd660
Author: Philip Withnall <withnall endlessm com>
Date:   Tue Apr 30 11:01:20 2019 +0100

    gqueue: Remove a redundant branch
    
    queue->tail->next cannot be non-NULL, as pushing onto the end of the
    queue is handled by the call to g_queue_push_tail_link() above.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>

 glib/gqueue.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/glib/gqueue.c b/glib/gqueue.c
index e8c938a25..0cc7ab200 100644
--- a/glib/gqueue.c
+++ b/glib/gqueue.c
@@ -519,8 +519,10 @@ g_queue_push_nth_link (GQueue *queue,
   if (queue->head->prev)
     queue->head = queue->head->prev;
 
-  if (queue->tail->next)
-    queue->tail = queue->tail->next;
+  /* The case where we’re pushing @link_ at the end of @queue is handled above
+   * using g_queue_push_tail_link(), so we should never have to manually adjust
+   * queue->tail. */
+  g_assert (queue->tail->next == NULL);
   
   queue->length++;
 }