pbx: Prevent execution of NULL pointer.

pbx_extension_helper has a check for q->swo.exec == NULL but it doesn't
actually return so we would still run the function.  Fix the return.
Move the 'int res' variable into the only scope which uses it.

Change-Id: I0693af921fdc7f56b6a72a21fb816ed08b960a69

diff --git a/main/pbx.c b/main/pbx.c
index 173b62e999cc2ba1086cc94b738c9ab980d9aae0..b313e05289c27aae5637ec593a55f54aab999069 100644 (file)
--- a/main/pbx.c
+++ b/main/pbx.c
@@ -2823,7 +2823,6 @@ static int pbx_extension_helper(struct ast_channel *c, struct ast_context *con,
        struct ast_exten *e;
        struct ast_app *app;
        char *substitute = NULL;
-       int res;
        struct pbx_find_info q = { .stacklen = 0 }; /* the rest is reset in pbx_find_extension */
        char passdata[EXT_DATA_SIZE];
        int matching_action = (action == E_MATCH || action == E_CANMATCH || action == E_MATCHMORE);
@@ -2840,9 +2839,12 @@ static int pbx_extension_helper(struct ast_channel *c, struct ast_context *con,
                        ast_unlock_contexts();
                        return -1;      /* success, we found it */
                } else if (action == E_FINDLABEL) { /* map the label to a priority */
-                       res = e->priority;
+                       int res = e->priority;
+
                        ast_unlock_contexts();
-                       return res;     /* the priority we were looking for */
+
+                       /* the priority we were looking for */
+                       return res;
                } else {        /* spawn */
                        if (!e->cached_app)
                                e->cached_app = pbx_findapp(e->app);
@@ -2892,7 +2894,7 @@ static int pbx_extension_helper(struct ast_channel *c, struct ast_context *con,
                } else {
                        if (!q.swo->exec) {
                                ast_log(LOG_WARNING, "No execution engine for switch %s\n", q.swo->name);
-                               res = -1;
+                               return -1;
                        }
                        return q.swo->exec(c, q.foundcontext ? q.foundcontext : context, exten, priority, callerid, q.data);
                }