From e63a3a7f310b8e8b45b24d75ade8084c246c6b7b Mon Sep 17 00:00:00 2001
From: Seungha Yang <seungha@centricular.com>
Date: Thu, 6 Jan 2022 22:00:11 +0900
Subject: [PATCH] d3d11compositor: Don't try to read empty buffer

The queued buffer may not be readable buffer in case that
upstream sends GAP event or so.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1497>
---
 .../gst-plugins-bad/sys/d3d11/gstd3d11compositor.cpp        | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/subprojects/gst-plugins-bad/sys/d3d11/gstd3d11compositor.cpp b/subprojects/gst-plugins-bad/sys/d3d11/gstd3d11compositor.cpp
index 0c70873c2b..aa319eec8e 100644
--- a/subprojects/gst-plugins-bad/sys/d3d11/gstd3d11compositor.cpp
+++ b/subprojects/gst-plugins-bad/sys/d3d11/gstd3d11compositor.cpp
@@ -2429,6 +2429,12 @@ gst_d3d11_compositor_check_device_update (GstElement * agg,
   if (!buf)
     return TRUE;
 
+  /* Ignore gap buffer */
+  if (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_GAP) ||
+      gst_buffer_get_size (buf) == 0) {
+    return TRUE;
+  }
+
   mem = gst_buffer_peek_memory (buf, 0);
   /* FIXME: we should be able to accept non-d3d11 memory later once
    * we remove intermediate elements (d3d11upload and d3d11colorconvert)