[gtk+] treestore: fix transformation of GValues on set

[Cosimo Cecchi <cosimoc src gnome org>]

commit a24f7564b59a663e0208793fcfa53fa43a6e81da
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Thu Jun 7 16:05:27 2012 -0400

    treestore: fix transformation of GValues on set
    
    There are three bugs here:
    - we should check if the value type is transformable instead of being
      compatible, since that's all we care about in order to call
      g_value_transform()
    - the check is only meaningful in the direction
      passed-in-type->column-type and not viceversa
    - we should init the destination GValue to the column type before
      calling g_value_transform on it, or the destination type information
      will be missing and the method will fail
    
    Thanks to Jasper St. Pierre and Colin Walters for all the help in
    tracking this down.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=677649

 gtk/gtktreestore.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtktreestore.c b/gtk/gtktreestore.c
index 773a256..6271359 100644
--- a/gtk/gtktreestore.c
+++ b/gtk/gtktreestore.c
@@ -853,8 +853,7 @@ gtk_tree_store_real_set_value (GtkTreeStore *tree_store,
 
   if (! g_type_is_a (G_VALUE_TYPE (value), priv->column_headers[column]))
     {
-      if (! (g_value_type_compatible (G_VALUE_TYPE (value), priv->column_headers[column]) &&
-	     g_value_type_compatible (priv->column_headers[column], G_VALUE_TYPE (value))))
+      if (! (g_value_type_transformable (G_VALUE_TYPE (value), priv->column_headers[column])))
 	{
 	  g_warning ("%s: Unable to convert from %s to %s\n",
 		     G_STRLOC,
@@ -862,6 +861,8 @@ gtk_tree_store_real_set_value (GtkTreeStore *tree_store,
 		     g_type_name (priv->column_headers[column]));
 	  return retval;
 	}
+
+      g_value_init (&real_value, priv->column_headers[column]);
       if (!g_value_transform (value, &real_value))
 	{
 	  g_warning ("%s: Unable to make conversion from %s to %s\n",