[phodav] spice-webdavd: add more preconditions

[Marc-Andre Lureau <malureau src gnome org>]

commit 6d08240698dd6093cc0faeed3f1c27d9917f1f1c
Author: Marc-André Lureau <marcandre lureau gmail com>
Date:   Mon Feb 9 14:27:39 2015 +0100

    spice-webdavd: add more preconditions

 spice/spice-webdavd.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/spice/spice-webdavd.c b/spice/spice-webdavd.c
index 2235bcb..07b9086 100644
--- a/spice/spice-webdavd.c
+++ b/spice/spice-webdavd.c
@@ -92,6 +92,8 @@ output_queue_ref (OutputQueue *q)
 static void
 output_queue_unref (OutputQueue *q)
 {
+  g_return_if_fail (q != NULL);
+
   q->refs--;
   if (q->refs == 0)
     output_queue_free (q);
@@ -171,8 +173,11 @@ static void
 output_queue_push (OutputQueue *q, const guint8 *buf, gsize size,
                    PushedCb pushed_cb, gpointer user_data)
 {
-  OutputQueueElem *e = g_new (OutputQueueElem, 1);
+  OutputQueueElem *e;
+
+  g_return_if_fail (q != NULL);
 
+  e = g_new (OutputQueueElem, 1);
   e->buf = buf;
   e->size = size;
   e->cb = pushed_cb;