Don't attempt to purge sessions when no sessions exist

Manager's tcp/tls objects have a periodic function that purge old manager
sessions periodically.  During shutdown, the underlying container holding
those sessions can be disposed of and set to NULL before the tcp/tls periodic
function is stopped.  If the periodic function fires, it will attempt to
iterate over a NULL container.

This patch checks for whether or not the sessions container exists before
attempting to purge sessions out of it.  If the sessions container is NULL,
we simply return.

Note that this error was also caught by the Asterisk Test Suite.
........

Merged revisions 375800 from http://svn.asterisk.org/svn/asterisk/branches/1.8

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@375801 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/main/manager.c b/main/manager.c
index 22405828117bf711ded67ec4f38eae020b403627..34bd8b4dfa641d627bc8cb2c6e5397a6d7c3f1d8 100644 (file)
--- a/main/manager.c
+++ b/main/manager.c
@@ -5221,6 +5221,10 @@ static void purge_sessions(int n_max)
        time_t now = time(NULL);
        struct ao2_iterator i;
 
+       if (!sessions) {
+               return;
+       }
+
        i = ao2_iterator_init(sessions, 0);
        while ((session = ao2_iterator_next(&i)) && n_max > 0) {
                ao2_lock(session);