[balsa/gtk3] Do not crash after deleting address book

[Peter Bloomfield <peterb src gnome org>]

commit 8516cf63f76b962c6afa450567875716a56fd0d1
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Fri Feb 20 18:42:54 2015 -0500

    Do not crash after deleting address book
    
        * src/ab-main.c (address_book_change_state): do not crash after
        deleting address book.

 ChangeLog     |    5 +++++
 src/ab-main.c |    2 +-
 2 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 98a6463..e4f7137 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2015-02-20  Peter Bloomfield  <pbloomfield bellsouth net>
 
+       * src/ab-main.c (address_book_change_state): do not crash after
+       deleting address book.
+
+2015-02-20  Peter Bloomfield  <pbloomfield bellsouth net>
+
        * libbalsa/application-helpers.c (libbalsa_window_get_menu_bar),
        (libbalsa_window_set_accels): remove old accel group before
        setting new one.
diff --git a/src/ab-main.c b/src/ab-main.c
index 3bdddbc..c66e299 100644
--- a/src/ab-main.c
+++ b/src/ab-main.c
@@ -231,7 +231,7 @@ address_book_change_state(GSimpleAction * action,
     value = g_variant_get_string(state, NULL);
     for (l = contacts_app.address_book_list; l; l = l->next) {
         address_book = l->data;
-        if (strcmp(value, address_book->name) == 0)
+        if (address_book && strcmp(value, address_book->name) == 0)
             break;
     }