From 4e3cb77fa8ed0e71793a06e7aa5a46233c5dfe00 Mon Sep 17 00:00:00 2001
From: Matthew Waters <matthew@centricular.com>
Date: Wed, 5 Oct 2016 12:11:19 +1100
Subject: [PATCH] vkdisplay: hold a weakref on the list of windows

It's possible that the window may have been destroyed when a winsys
event comes in for it.

Fixes an assertion in make -C tests/check generic/states.check
---
 ext/vulkan/vkdisplay.c | 35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/ext/vulkan/vkdisplay.c b/ext/vulkan/vkdisplay.c
index 096f251a8d..550134cd83 100644
--- a/ext/vulkan/vkdisplay.c
+++ b/ext/vulkan/vkdisplay.c
@@ -284,8 +284,12 @@ gst_vulkan_display_create_window (GstVulkanDisplay * display)
   window = klass->create_window (display);
 
   if (window) {
+    GWeakRef *ref = g_new0 (GWeakRef, 1);
+
+    g_weak_ref_set (ref, window);
+
     GST_OBJECT_LOCK (display);
-    display->windows = g_list_prepend (display->windows, window);
+    display->windows = g_list_prepend (display->windows, ref);
     GST_OBJECT_UNLOCK (display);
   }
 
@@ -298,6 +302,31 @@ gst_vulkan_display_default_create_window (GstVulkanDisplay * display)
   return gst_vulkan_window_new (display);
 }
 
+static gint
+_compare_vulkan_window (GWeakRef * ref, GstVulkanWindow * window)
+{
+  GstVulkanWindow *other = g_weak_ref_get (ref);
+  gboolean equal = window == other;
+
+  gst_object_unref (other);
+
+  return !equal;
+}
+
+static GList *
+_find_window_list_item (GstVulkanDisplay * display, GstVulkanWindow * window)
+{
+  GList *l;
+
+  if (!window)
+    return NULL;
+
+  l = g_list_find_custom (display->windows, window,
+      (GCompareFunc) _compare_vulkan_window);
+
+  return l;
+}
+
 gboolean
 gst_vulkan_display_remove_window (GstVulkanDisplay * display,
     GstVulkanWindow * window)
@@ -306,9 +335,11 @@ gst_vulkan_display_remove_window (GstVulkanDisplay * display,
   GList *l;
 
   GST_OBJECT_LOCK (display);
-  l = g_list_find (display->windows, window);
+  l = _find_window_list_item (display, window);
   if (l) {
     display->windows = g_list_delete_link (display->windows, l);
+    g_weak_ref_clear (l->data);
+    g_free (l->data);
     ret = TRUE;
   }
   GST_OBJECT_UNLOCK (display);