From b18b3d00b7067c2ab092456b94e214e5c6c93711 Mon Sep 17 00:00:00 2001
From: Alexander Slobodeniuk <aslobodeniuk@fluendo.com>
Date: Thu, 28 Mar 2024 21:46:11 +0100
Subject: [PATCH] navigation: add missing sanity checks

On practice a failure happened due to a race condition, the instance
already have been freed, but it could also happen if the instance
would be null.
Instead of crashing this sanity check is a more suitable option,
since with G_DEBUG=fatal-warnings it will crash too.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6475>
---
 .../gst-libs/gst/video/navigation.c               | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/subprojects/gst-plugins-base/gst-libs/gst/video/navigation.c b/subprojects/gst-plugins-base/gst-libs/gst/video/navigation.c
index 09411ce0d2..8cf2154b74 100644
--- a/subprojects/gst-plugins-base/gst-libs/gst/video/navigation.c
+++ b/subprojects/gst-plugins-base/gst-libs/gst/video/navigation.c
@@ -93,8 +93,11 @@ gst_navigation_default_init (GstNavigationInterface * iface)
 void
 gst_navigation_send_event (GstNavigation * navigation, GstStructure * structure)
 {
-  GstNavigationInterface *iface = GST_NAVIGATION_GET_INTERFACE (navigation);
+  GstNavigationInterface *iface;
 
+  g_return_if_fail (GST_IS_NAVIGATION (navigation));
+
+  iface = GST_NAVIGATION_GET_INTERFACE (navigation);
   if (iface->send_event) {
     iface->send_event (navigation, structure);
   } else if (iface->send_event_simple) {
@@ -116,6 +119,7 @@ void
 gst_navigation_send_key_event (GstNavigation * navigation, const char *event,
     const char *key)
 {
+  g_return_if_fail (GST_IS_NAVIGATION (navigation));
   g_return_if_fail (g_strcmp0 (event, "key-press") == 0 ||
       g_strcmp0 (event, "key-release") == 0);
 
@@ -144,6 +148,7 @@ void
 gst_navigation_send_mouse_event (GstNavigation * navigation, const char *event,
     int button, double x, double y)
 {
+  g_return_if_fail (GST_IS_NAVIGATION (navigation));
   g_return_if_fail (g_strcmp0 (event, "mouse-button-press") == 0 ||
       g_strcmp0 (event, "mouse-button-release") == 0 ||
       g_strcmp0 (event, "mouse-move") == 0);
@@ -173,6 +178,8 @@ void
 gst_navigation_send_mouse_scroll_event (GstNavigation * navigation,
     double x, double y, double delta_x, double delta_y)
 {
+  g_return_if_fail (GST_IS_NAVIGATION (navigation));
+
   gst_navigation_send_event (navigation,
       gst_structure_new (GST_NAVIGATION_EVENT_NAME,
           "event", G_TYPE_STRING, "mouse-scroll",
@@ -193,6 +200,8 @@ void
 gst_navigation_send_command (GstNavigation * navigation,
     GstNavigationCommand command)
 {
+  g_return_if_fail (GST_IS_NAVIGATION (navigation));
+
   gst_navigation_send_event (navigation,
       gst_structure_new (GST_NAVIGATION_EVENT_NAME, "event", G_TYPE_STRING,
           "command", "command-code", G_TYPE_UINT, (guint) command, NULL));
@@ -209,10 +218,12 @@ gst_navigation_send_command (GstNavigation * navigation,
 void
 gst_navigation_send_event_simple (GstNavigation * navigation, GstEvent * event)
 {
-  GstNavigationInterface *iface = GST_NAVIGATION_GET_INTERFACE (navigation);
+  GstNavigationInterface *iface;
 
+  g_return_if_fail (GST_IS_NAVIGATION (navigation));
   g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_NAVIGATION);
 
+  iface = GST_NAVIGATION_GET_INTERFACE (navigation);
   if (iface->send_event_simple) {
     iface->send_event_simple (navigation, event);
   } else if (iface->send_event) {