don't crash if no group is specified (bug #4836)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@6237 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/funcs/func_groupcount.c b/funcs/func_groupcount.c
index 292364a..66a7367 100755 (executable)
--- a/funcs/func_groupcount.c
+++ b/funcs/func_groupcount.c
@@ -33,8 +33,10 @@ static char *group_count_function_read(struct ast_channel *chan, char *cmd, char
        ast_app_group_split_group(data, group, sizeof(group), category, sizeof(category));
 
        if (ast_strlen_zero(group)) {
-               grp = pbx_builtin_getvar_helper(chan, category);
-               ast_copy_string(group, grp, sizeof(group));
+               if ((grp = pbx_builtin_getvar_helper(chan, category)))
+                       ast_copy_string(group, grp, sizeof(group));
+               else
+                       return buf;
        }
 
        count = ast_app_group_get_count(group, category);