[glib] Guard g_inet_address_mask_equal against invalid input

[Dan Winship <danw src gnome org>]

commit 92d67358986c3be48ccbd4135b53ea591f15ea86
Author: Erik van Pienbroek <epienbro fedoraproject org>
Date:   Thu Jul 17 18:37:04 2014 +0200

    Guard g_inet_address_mask_equal against invalid input
    
    https://bugzilla.gnome.org/show_bug.cgi?id=733338

 gio/ginetaddressmask.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/gio/ginetaddressmask.c b/gio/ginetaddressmask.c
index b33c2f9..f717c77 100644
--- a/gio/ginetaddressmask.c
+++ b/gio/ginetaddressmask.c
@@ -465,6 +465,9 @@ gboolean
 g_inet_address_mask_equal (GInetAddressMask  *mask,
                           GInetAddressMask  *mask2)
 {
+  g_return_val_if_fail (G_IS_INET_ADDRESS_MASK (mask), FALSE);
+  g_return_val_if_fail (G_IS_INET_ADDRESS_MASK (mask2), FALSE);
+
   return ((mask->priv->length == mask2->priv->length) &&
          g_inet_address_equal (mask->priv->addr, mask2->priv->addr));
 }