[folks] Don't crash if a provided TpContact ID is NULL.

[Travis Reitter <treitter src gnome org>]

commit 3c5ebf360d0dd934928683f6d1ee41c6ba106e91
Author: Travis Reitter <travis reitter collabora co uk>
Date:   Tue Jun 21 15:08:45 2011 -0700

    Don't crash if a provided TpContact ID is NULL.

 tests/lib/telepathy/contactlist/conn.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/tests/lib/telepathy/contactlist/conn.c b/tests/lib/telepathy/contactlist/conn.c
index 7a15121..748abef 100644
--- a/tests/lib/telepathy/contactlist/conn.c
+++ b/tests/lib/telepathy/contactlist/conn.c
@@ -178,7 +178,7 @@ tp_test_contact_list_normalize_contact (TpHandleRepoIface *repo,
                                         gpointer context,
                                         GError **error)
 {
-  if (id[0] == '\0')
+  if (id == NULL || id[0] == '\0')
     {
       g_set_error (error, TP_ERRORS, TP_ERROR_INVALID_HANDLE,
           "Contact ID must not be empty");
@@ -194,7 +194,7 @@ tp_test_contact_list_normalize_group (TpHandleRepoIface *repo,
                                       gpointer context,
                                       GError **error)
 {
-  if (id[0] == '\0')
+  if (id == NULL || id[0] == '\0')
     {
       g_set_error (error, TP_ERRORS, TP_ERROR_INVALID_HANDLE,
           "Contact group name cannot be empty");