Nikolay Sivov : mf: Handle null marker context for sample grabber stream.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: a12b5fe084510fab7f5b0e3a6665160becb59511
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=a12b5fe084510fab7f5b0e3a6665160becb59511

Author: Nikolay Sivov <nsivov at codeweavers.com>
Date:   Fri Apr 24 17:47:03 2020 +0300

mf: Handle null marker context for sample grabber stream.

Signed-off-by: Nikolay Sivov <nsivov at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>

---

 dlls/mf/samplegrabber.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/dlls/mf/samplegrabber.c b/dlls/mf/samplegrabber.c
index 21f89c0ad0..2167b5001e 100644
--- a/dlls/mf/samplegrabber.c
+++ b/dlls/mf/samplegrabber.c
@@ -446,7 +446,7 @@ static HRESULT stream_place_marker(struct sample_grabber *grabber, MFSTREAMSINK_
         const PROPVARIANT *context_value)
 {
     struct scheduled_item *item;
-    HRESULT hr;
+    HRESULT hr = S_OK;
 
     if (list_empty(&grabber->items))
     {
@@ -460,7 +460,9 @@ static HRESULT stream_place_marker(struct sample_grabber *grabber, MFSTREAMSINK_
     item->type = ITEM_TYPE_MARKER;
     item->u.marker.type = marker_type;
     list_init(&item->entry);
-    hr = PropVariantCopy(&item->u.marker.context, context_value);
+    PropVariantInit(&item->u.marker.context);
+    if (context_value)
+        hr = PropVariantCopy(&item->u.marker.context, context_value);
     if (SUCCEEDED(hr))
         list_add_tail(&grabber->items, &item->entry);
     else