[gthumb] use a better error message when the catalog already exists

[Paolo Bacchilega <paobac src gnome org>]

commit 7653a60f01c7efbe9e9c5287d8e5214578d09b12
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Sun Dec 11 18:01:51 2011 +0100

    use a better error message when the catalog already exists

 extensions/catalogs/gth-file-source-catalogs.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/extensions/catalogs/gth-file-source-catalogs.c b/extensions/catalogs/gth-file-source-catalogs.c
index 1814093..92092f0 100644
--- a/extensions/catalogs/gth-file-source-catalogs.c
+++ b/extensions/catalogs/gth-file-source-catalogs.c
@@ -498,10 +498,15 @@ gth_file_source_catalogs_rename (GthFileSource *file_source,
 		}
 	}
 
+	if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_EXISTS)) {
+		g_clear_error (&error);
+		error = g_error_new_literal (G_IO_ERROR, G_IO_ERROR_EXISTS, _("Name already used"));
+	}
+
 	object_ready_with_error (file_source, callback, data, error);
 
 	_g_object_unref (new_file);
-	g_object_unref (catalog);
+	_g_object_unref (catalog);
 }