3 files changed, 61 insertions, 25 deletions

diff --git a/res/stasis/control.c b/res/stasis/control.c
index 97b0b8809..b2b076b73 100644
--- a/res/stasis/control.c
+++ b/res/stasis/control.c
@@ -323,7 +323,7 @@ static int app_control_dial(struct stasis_app_control *control,
 		AST_BRIDGE_IMPART_CHAN_INDEPENDENT)) {
 		ast_hangup(new_chan);
 	} else {
-		control_add_channel_to_bridge(control, chan, bridge);
+		control_swap_channel_in_bridge(control, bridge, chan, NULL);
 	}
 
 	return 0;
@@ -982,11 +982,8 @@ static void bridge_after_cb_failed(enum ast_bridge_after_cb_reason reason,
 		ast_bridge_after_cb_reason_string(reason));
 }
 
-int control_add_channel_to_bridge(
-	struct stasis_app_control *control,
-	struct ast_channel *chan, void *data)
+int control_swap_channel_in_bridge(struct stasis_app_control *control, struct ast_bridge *bridge, struct ast_channel *chan, struct ast_channel *swap)
 {
-	struct ast_bridge *bridge = data;
 	int res;
 
 	if (!control || !bridge) {
@@ -1039,7 +1036,7 @@ int control_add_channel_to_bridge(
 
 		res = ast_bridge_impart(bridge,
 			chan,
-			NULL, /* swap channel */
+			swap,
 			NULL, /* features */
 			AST_BRIDGE_IMPART_CHAN_DEPARTABLE);
 		if (res != 0) {
@@ -1055,6 +1052,11 @@ int control_add_channel_to_bridge(
 	return 0;
 }
 
+int control_add_channel_to_bridge(struct stasis_app_control *control, struct ast_channel *chan, void *data)
+{
+	return control_swap_channel_in_bridge(control, data, chan, NULL);
+}
+
 int stasis_app_control_add_channel_to_bridge(
 	struct stasis_app_control *control, struct ast_bridge *bridge)
 {
diff --git a/res/stasis/control.h b/res/stasis/control.h
index 1d37a494a..868a8091b 100644
--- a/res/stasis/control.h
+++ b/res/stasis/control.h
@@ -111,12 +111,20 @@ struct stasis_app *control_app(struct stasis_app_control *control);
  * \brief Command callback for adding a channel to a bridge
  *
  * \param control The control for chan
- * \param channel The channel on which commands should be executed
- * \param bridge Data to be passed to the callback
+ * \param chan The channel on which commands should be executed
+ * \param data Bridge to be passed to the callback
+ */
+int control_add_channel_to_bridge(struct stasis_app_control *control, struct ast_channel *chan, void *data);
+
+/*!
+ * \brief Command for swapping a channel in a bridge
+ *
+ * \param control The control for chan
+ * \param chan The channel on which commands should be executed
+ * \param bridge Bridge to be passed to the callback
+ * \param swap Channel to swap with when joining the bridge
  */
-int control_add_channel_to_bridge(
-	struct stasis_app_control *control,
-	struct ast_channel *chan, void *obj);
+int control_swap_channel_in_bridge(struct stasis_app_control *control, struct ast_bridge *bridge, struct ast_channel *chan, struct ast_channel *swap);
 
 /*!
  * \brief Stop playing silence to a channel right now.
diff --git a/res/stasis/stasis_bridge.c b/res/stasis/stasis_bridge.c
index f97673d78..9ffc2d7be 100644
--- a/res/stasis/stasis_bridge.c
+++ b/res/stasis/stasis_bridge.c
@@ -76,24 +76,54 @@ static void bridge_stasis_run_cb(struct ast_channel *chan, void *data)
 	pbx_exec(chan, app_stasis, app_name);
 }
 
-static int add_channel_to_bridge(
+struct defer_bridge_add_obj {
+	/*! Bridge to join (has ref) */
+	struct ast_bridge *bridge;
+	/*!
+	 * \brief Channel to swap with in the bridge. (has ref)
+	 *
+	 * \note NULL if not swapping with a channel.
+	 */
+	struct ast_channel *swap;
+};
+
+static void defer_bridge_add_dtor(void *obj)
+{
+	struct defer_bridge_add_obj *defer = obj;
+
+	ao2_cleanup(defer->bridge);
+	ast_channel_cleanup(defer->swap);
+}
+
+static int defer_bridge_add(
 	struct stasis_app_control *control,
 	struct ast_channel *chan, void *obj)
 {
-	struct ast_bridge *bridge = obj;
-	int res;
+	struct defer_bridge_add_obj *defer = obj;
 
-	res = control_add_channel_to_bridge(control,
-		chan, bridge);
-	return res;
+	return control_swap_channel_in_bridge(control, defer->bridge, chan, defer->swap);
 }
 
 static void bridge_stasis_queue_join_action(struct ast_bridge *self,
-	struct ast_bridge_channel *bridge_channel)
+	struct ast_bridge_channel *bridge_channel, struct ast_bridge_channel *swap)
 {
+	struct defer_bridge_add_obj *defer;
+
+	defer = ao2_alloc_options(sizeof(*defer), defer_bridge_add_dtor,
+		AO2_ALLOC_OPT_LOCK_NOLOCK);
+	if (!defer) {
+		return;
+	}
+	ao2_ref(self, +1);
+	defer->bridge = self;
+	if (swap) {
+		ast_channel_ref(swap->chan);
+		defer->swap = swap->chan;
+	}
+
 	ast_channel_lock(bridge_channel->chan);
-	command_prestart_queue_command(bridge_channel->chan, add_channel_to_bridge,
-		ao2_bump(self), __ao2_cleanup);
+	command_prestart_queue_command(bridge_channel->chan, defer_bridge_add,
+		defer, __ao2_cleanup);
 	ast_channel_unlock(bridge_channel->chan);
 }
 
@@ -179,11 +209,7 @@ static int bridge_stasis_push(struct ast_bridge *self, struct ast_bridge_channel
 			return -1;
 		}
 
-		bridge_stasis_queue_join_action(self, bridge_channel);
-		if (swap) {
-			/* nudge the swap channel out of the bridge */
-			ast_bridge_channel_leave_bridge(swap, BRIDGE_CHANNEL_STATE_END_NO_DISSOLVE, 0);
-		}
+		bridge_stasis_queue_join_action(self, bridge_channel, swap);
 
 		/* Return -1 so the push fails and the after-bridge callback gets called
 		 * This keeps the bridging framework from putting the channel into the bridge