mfplat: Append MFVIDEOFORMAT user data after the structure padding.

dlls/mfplat/mediatype.c

@@ -3864,10 +3864,14 @@ HRESULT WINAPI MFInitMediaTypeFromMFVideoFormat(IMFMediaType *media_type, const
     if (format->compressedInfo.MaxKeyFrameSpacing)
         mediatype_set_uint32(media_type, &MF_MT_MAX_KEYFRAME_SPACING, format->compressedInfo.MaxKeyFrameSpacing, &hr);
 
-    if ((palette_size = format->surfaceInfo.PaletteEntries * sizeof(*format->surfaceInfo.Palette)))
+    if (!(palette_size = format->surfaceInfo.PaletteEntries * sizeof(*format->surfaceInfo.Palette)))
+        user_data = format + 1;
+    else
+    {
         mediatype_set_blob(media_type, &MF_MT_PALETTE, (BYTE *)format->surfaceInfo.Palette, palette_size, &hr);
-
         user_data = &format->surfaceInfo.Palette[format->surfaceInfo.PaletteEntries + 1];
+    }
+
     if ((user_data_size = (BYTE *)format + format->dwSize - (BYTE *)user_data))
         mediatype_set_blob(media_type, &MF_MT_USER_DATA, user_data, user_data_size, &hr);
 

dlls/mfplat/tests/mfplat.c

@@ -8448,6 +8448,20 @@ static void test_MFInitMediaTypeFromMFVideoFormat(void)
     ok(!memcmp(user_data, expect_user_data, value32), "Unexpected user data.\n");
     IMFMediaType_DeleteAllItems(media_type);
 
+    /* check that user data follows MFVIDEOFORMAT struct, which is padded, when no palette is present */
+    format_buf->surfaceInfo.PaletteEntries = 0;
+    memmove(format_buf + 1, expect_user_data, sizeof(expect_user_data));
+    format_buf->dwSize = sizeof(*format_buf) + sizeof(expect_user_data);
+    hr = MFInitMediaTypeFromMFVideoFormat(media_type, format_buf, format_buf->dwSize);
+    ok(hr == S_OK, "Unexpected hr %#lx.\n", hr);
+    value32 = 0xdeadbeef;
+    memset(&user_data, 0xcd, sizeof(user_data));
+    hr = IMFMediaType_GetBlob(media_type, &MF_MT_USER_DATA, (BYTE *)user_data, sizeof(user_data), &value32);
+    ok(hr == S_OK, "Unexpected hr %#lx.\n", hr);
+    ok(value32 == sizeof(expect_user_data), "got %u.\n", value32);
+    ok(!memcmp(user_data, expect_user_data, value32), "Unexpected user data.\n");
+    IMFMediaType_DeleteAllItems(media_type);
+
     IMFMediaType_Release(media_type);
 }