mfplay: Handle NULL item in SetMediaItem().

dlls/mfplay/player.c

@@ -1224,12 +1224,16 @@ static HRESULT media_item_create_topology(struct media_player *player, struct me
 static HRESULT WINAPI media_player_SetMediaItem(IMFPMediaPlayer *iface, IMFPMediaItem *item_iface)
 {
     struct media_player *player = impl_from_IMFPMediaPlayer(iface);
-    struct media_item *item = unsafe_impl_from_IMFPMediaItem(item_iface);
+    struct media_item *item;
     IMFTopology *topology;
     HRESULT hr;
 
     TRACE("%p, %p.\n", iface, item_iface);
 
+    if (!item_iface)
+        return E_POINTER;
+
+    item = unsafe_impl_from_IMFPMediaItem(item_iface);
     if (item->player != iface)
         return E_INVALIDARG;
 

dlls/mfplay/tests/mfplay.c

@@ -198,8 +198,23 @@ static void test_shutdown(void)
     IMFPMediaPlayer_Release(player);
 }
 
+static void test_media_item(void)
+{
+    IMFPMediaPlayer *player;
+    HRESULT hr;
+
+    hr = MFPCreateMediaPlayer(NULL, FALSE, 0, NULL, NULL, &player);
+    ok(hr == S_OK, "Unexpected hr %#x.\n", hr);
+
+    hr = IMFPMediaPlayer_SetMediaItem(player, NULL);
+    ok(hr == E_POINTER, "Unexpected hr %#x.\n", hr);
+
+    IMFPMediaPlayer_Release(player);
+}
+
 START_TEST(mfplay)
 {
     test_create_player();
     test_shutdown();
+    test_media_item();
 }