[gjs] Bug 586665: Fix seg fault when attempting to free callback type.

[C. Scott Ananian <cananian src gnome org>]

commit 1f19b470cb5c13d7280b34636be4eeb016f704b1
Author: C. Scott Ananian <cscott litl com>
Date:   Fri Jun 5 18:29:25 2009 -0400

    Bug 586665: Fix seg fault when attempting to free callback type.

 gi/arg.c |   28 +++++++++++++++++++++++++++-
 1 files changed, 27 insertions(+), 1 deletions(-)
---
diff --git a/gi/arg.c b/gi/arg.c
index a966197..008784d 100644
--- a/gi/arg.c
+++ b/gi/arg.c
@@ -154,13 +154,39 @@ type_needs_release (GITypeInfo *type_info,
         return TRUE;
     case GI_TYPE_TAG_INTERFACE: {
         GIBaseInfo* interface_info;
+        GIInfoType interface_type;
         GType gtype;
         gboolean needs_release;
 
         interface_info = g_type_info_get_interface(type_info);
         g_assert(interface_info != NULL);
 
-        gtype = g_registered_type_info_get_g_type((GIRegisteredTypeInfo*)interface_info);
+        interface_type = g_base_info_get_type(interface_info);
+
+        switch(interface_type) {
+
+        case GI_INFO_TYPE_STRUCT:
+        case GI_INFO_TYPE_ENUM:
+        case GI_INFO_TYPE_OBJECT:
+        case GI_INFO_TYPE_INTERFACE:
+        case GI_INFO_TYPE_UNION:
+        case GI_INFO_TYPE_BOXED:
+            /* These are subtypes of GIRegisteredTypeInfo for which the
+             * cast is safe */
+            gtype = g_registered_type_info_get_g_type
+                ((GIRegisteredTypeInfo*)interface_info);
+            break;
+
+        case GI_INFO_TYPE_VALUE:
+            /* Special case for GValues */
+            gtype = G_TYPE_VALUE;
+            break;
+
+        default:
+            /* Everything else */
+            gtype = G_TYPE_NONE;
+            break;
+        }
 
         if (g_type_is_a(gtype, G_TYPE_CLOSURE) || g_type_is_a(gtype, G_TYPE_VALUE))
             needs_release = TRUE;