[gnome-builder/wip/chergert/debugger: 93/106] egg-signal-group: add support for interfaces

[Christian Hergert <chergert src gnome org>]

commit 70dd298de9a71a3dcdd8514f5d15055de257e466
Author: Christian Hergert <chergert redhat com>
Date:   Sun Mar 26 17:44:55 2017 -0700

    egg-signal-group: add support for interfaces
    
    We need to pre-load the type if it is an interface, just like we do for
    classes.

 contrib/egg/egg-signal-group.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)
---
diff --git a/contrib/egg/egg-signal-group.c b/contrib/egg/egg-signal-group.c
index 550bcc4..ff3fc9b 100644
--- a/contrib/egg/egg-signal-group.c
+++ b/contrib/egg/egg-signal-group.c
@@ -109,8 +109,16 @@ egg_signal_group_set_target_type (EggSignalGroup *self,
   /* The class must be created at least once for the signals
    * to be registered, otherwise g_signal_parse_name() will fail
    */
-  if (g_type_class_peek (target_type) == NULL)
-    g_type_class_unref (g_type_class_ref (target_type));
+  if (G_TYPE_IS_INTERFACE (target_type))
+    {
+      if (g_type_default_interface_peek (target_type) == NULL)
+        g_type_default_interface_unref (g_type_default_interface_ref (target_type));
+    }
+  else
+    {
+      if (g_type_class_peek (target_type) == NULL)
+        g_type_class_unref (g_type_class_ref (target_type));
+    }
 }
 
 static void