[at-spi2-core] Change some error return values to match AT-SPI-CORBA behavior

[Mike Gorse <mgorse src gnome org>]

commit 3221e4d296e89888bade934a545d05b353b88526
Author: Mike Gorse <mgorse novell com>
Date:   Fri Dec 3 13:08:13 2010 -0500

    Change some error return values to match AT-SPI-CORBA behavior

 atspi/atspi-accessible.c |   18 ++++++++++++------
 1 files changed, 12 insertions(+), 6 deletions(-)
---
diff --git a/atspi/atspi-accessible.c b/atspi/atspi-accessible.c
index 13b0d73..9e5c503 100644
--- a/atspi/atspi-accessible.c
+++ b/atspi/atspi-accessible.c
@@ -242,12 +242,12 @@ atspi_role_get_name (AtspiRole role)
 gchar *
 atspi_accessible_get_name (AtspiAccessible *obj, GError **error)
 {
-  g_return_val_if_fail (obj != NULL, NULL);
+  g_return_val_if_fail (obj != NULL, g_strdup (""));
   if (!(obj->cached_properties & ATSPI_CACHE_NAME))
   {
     if (!_atspi_dbus_get_property (obj, atspi_interface_accessible, "Name", error,
                                    "s", &obj->name))
-      return NULL;
+      return g_strdup ("");
     obj->cached_properties |= ATSPI_CACHE_NAME;
   }
   return g_strdup (obj->name);
@@ -265,12 +265,12 @@ atspi_accessible_get_name (AtspiAccessible *obj, GError **error)
 gchar *
 atspi_accessible_get_description (AtspiAccessible *obj, GError **error)
 {
-  g_return_val_if_fail (obj != NULL, NULL);
+  g_return_val_if_fail (obj != NULL, g_strdup (""));
 
   if (!(obj->cached_properties & ATSPI_CACHE_DESCRIPTION))
   {
     if (!_atspi_dbus_call (obj, atspi_interface_accessible, "GetDescription", NULL, "=>s", &obj->description))
-      return NULL;
+      return g_strdup ("");
     obj->cached_properties |= ATSPI_CACHE_DESCRIPTION;
   }
   return g_strdup (obj->description);
@@ -506,10 +506,13 @@ atspi_accessible_get_role_name (AtspiAccessible *obj, GError **error)
 {
   char *retval = NULL;
 
-  g_return_val_if_fail (obj != NULL, g_strdup ("invalid"));
+  g_return_val_if_fail (obj != NULL, NULL);
 
   _atspi_dbus_call (obj, atspi_interface_accessible, "GetRoleName", error, "=>s", &retval);
 
+  if (!retval)
+    retval = g_strdup ("");
+
   return retval;
 }
 
@@ -529,10 +532,13 @@ atspi_accessible_get_localized_role_name (AtspiAccessible *obj, GError **error)
 {
   char *retval = NULL;
 
-  g_return_val_if_fail (obj != NULL, g_strdup ("invalid"));
+  g_return_val_if_fail (obj != NULL, NULL);
 
   _atspi_dbus_call (obj, atspi_interface_accessible, "GetLocalizedRoleName", error, "=>s", &retval);
 
+  if (!retval)
+    return g_strdup ("");
+
   return retval;
 }