hashtab: Add NULL check when destroying iterator.

The hashtab API is pretty NULL tolerant which has resulted
in remaining callers not doing much checks themselves.
Unfortunately the function to destroy an iterator does not
do a NULL check and will result in a crash if passed NULL.
This change fixes that.

ASTERISK-25552 #close

Change-Id: Ic1bf8eec3639e5a440f1c941d3ae3893ac6ed619

diff --git a/main/hashtab.c b/main/hashtab.c
index 4b765979f32768fdbc4c9baaf8a7ea272cc8f77f..9b334d4a53e88c7d850ff61860a15be83a5b6a09 100644 (file)
--- a/main/hashtab.c
+++ b/main/hashtab.c
@@ -745,6 +745,8 @@ struct ast_hashtab_iter *ast_hashtab_start_write_traversal(struct ast_hashtab *t
 
 void ast_hashtab_end_traversal(struct ast_hashtab_iter *it)
 {
+       if (!it)
+               return;
        if (it->tab->do_locking)
                ast_rwlock_unlock(&it->tab->lock);
        free(it);