When GOSUB is invoked within an AGI, it may not exit correctly.

(closes issue #16216)
 Reported by: atis
 Patches: 
       20091110__atis_work.diff.txt uploaded by tilghman (license 14)
 Tested by: atis


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@229351 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_stack.c

@@ -199,6 +199,7 @@ struct gosub_stack_frame {
 	unsigned char arguments;
 	struct varshead varshead;
 	int priority;
+	unsigned int is_agi:1;
 	char *context;
 	char extension[0];
 };
@@ -311,6 +312,7 @@ static int return_exec(struct ast_channel *chan, const char *data)
 	struct gosub_stack_frame *oldframe;
 	AST_LIST_HEAD(, gosub_stack_frame) *oldlist;
 	const char *retval = data;
+	int res = 0;
 
 	if (!stack_store) {
 		ast_log(LOG_ERROR, "Return without Gosub: stack is unallocated\n");
@@ -325,6 +327,9 @@ static int return_exec(struct ast_channel *chan, const char *data)
 	if (!oldframe) {
 		ast_log(LOG_ERROR, "Return without Gosub: stack is empty\n");
 		return -1;
+	} else if (oldframe->is_agi) {
+		/* Exit from AGI */
+		res = -1;
 	}
 
 	ast_explicit_goto(chan, oldframe->context, oldframe->extension, oldframe->priority);
@@ -332,7 +337,7 @@ static int return_exec(struct ast_channel *chan, const char *data)
 
 	/* Set a return value, if any */
 	pbx_builtin_setvar_helper(chan, "GOSUB_RETVAL", S_OR(retval, ""));
-	return 0;
+	return res;
 }
 
 static int gosub_exec(struct ast_channel *chan, const char *data)
@@ -619,6 +624,11 @@ static int handle_gosub(struct ast_channel *chan, AGI *agi, int argc, const char
 		if ((res = pbx_exec(chan, theapp, gosub_args)) == 0) {
 			struct ast_pbx *pbx = chan->pbx;
 			struct ast_pbx_args args;
+			struct ast_datastore *stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
+			AST_LIST_HEAD(, gosub_stack_frame) *oldlist = stack_store->data;
+			struct gosub_stack_frame *cur = AST_LIST_FIRST(oldlist);
+			cur->is_agi = 1;
+
 			memset(&args, 0, sizeof(args));
 			args.no_hangup_chan = 1;
 			/* Suppress warning about PBX already existing */