[mutter] prefs: Don't crash when we get a preference changed we don't know about

[Jasper St. Pierre <jstpierre src gnome org>]

commit 1445903a34fd339abadf9ef43ae7f53c4e157902
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Tue Aug 19 14:06:10 2014 -0400

    prefs: Don't crash when we get a preference changed we don't know about
    
    We commonly used the generic, undetailed signal 'changed' to track
    changes to preferences. Since we crash on unknown preference types,
    this can be dangerous if somebody adds a new setting that has a
    type we're unfamiliar with, and something else changes it.
    
    Instead of crashing, just fizzle out doing nothing.

 src/core/prefs.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/src/core/prefs.c b/src/core/prefs.c
index c1d5411..647f01a 100644
--- a/src/core/prefs.c
+++ b/src/core/prefs.c
@@ -1210,8 +1210,9 @@ settings_changed (GSettings *settings,
     }
   else
     {
-      /* Someone added a preference of an unhandled type */
-      g_assert_not_reached ();
+      /* Unknown preference type. This quite likely simply isn't
+       * a preference we track changes to. */
+      return;
     }
 
   g_variant_unref (value);