[evolution-data-server] evolution-source-viewer.c: Fix a frequent runtime warning.

[Matthew Barnes <mbarnes src gnome org>]

commit 021fb371e5b8b41e9cd77d1cc5b1c98be6005904
Author: Matthew Barnes <mbarnes redhat com>
Date:   Fri Jul 6 16:45:22 2012 -0400

    evolution-source-viewer.c: Fix a frequent runtime warning.

 tests/libedataserverui/evolution-source-viewer.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/tests/libedataserverui/evolution-source-viewer.c b/tests/libedataserverui/evolution-source-viewer.c
index 52c96d1..c6bbb50 100644
--- a/tests/libedataserverui/evolution-source-viewer.c
+++ b/tests/libedataserverui/evolution-source-viewer.c
@@ -994,10 +994,10 @@ e_source_viewer_build_display_tree (ESourceViewer *viewer)
 			parent_node = root;
 		} else {
 			parent_node = g_hash_table_lookup (index, parent_uid);
-			g_warn_if_fail (parent_node != NULL);
 		}
 
-		/* Should never be NULL, but just to be safe. */
+		/* This could be NULL if the registry service was
+		 * shutdown or reloaded.  All sources will vanish. */
 		if (parent_node != NULL)
 			g_node_append (parent_node, source_node);
 	}