[evolution-ews] ebews_start_gal_sync(): Avoid crash when EwsOALDetails list is NULL.

[Matthew Barnes <mbarnes src gnome org>]

commit 0320ac8d438213bafe24d8f696fea261aee49c54
Author: Matthew Barnes <mbarnes redhat com>
Date:   Fri Jun 15 07:42:48 2012 -0400

    ebews_start_gal_sync(): Avoid crash when EwsOALDetails list is NULL.

 src/addressbook/e-book-backend-ews.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/addressbook/e-book-backend-ews.c b/src/addressbook/e-book-backend-ews.c
index 759dcad..f49d3bb 100644
--- a/src/addressbook/e-book-backend-ews.c
+++ b/src/addressbook/e-book-backend-ews.c
@@ -1856,6 +1856,9 @@ ebews_start_gal_sync (gpointer data)
 	if (!priv->ebsdb)
 		goto exit;
 
+	if (full_l == NULL)
+		goto exit;
+
 	full = (EwsOALDetails *) full_l->data;
 	/* TODO fetch differential updates if available instead of downloading the whole GAL */
 	if (!ews_book_backend_sqlitedb_get_is_populated (priv->ebsdb, priv->folder_id, NULL) || ews_gal_needs_update (cbews, full, &error)) {