MSDN says:
> When you write .dds files, you should set the DDSD_CAPS and
> DDSD_PIXELFORMAT flags, and for mipmapped textures you should also
> set the DDSD_MIPMAPCOUNT flag. However, when you read a .dds file,
> you should not rely on the DDSD_CAPS, DDSD_PIXELFORMAT, and
> DDSD_MIPMAPCOUNT flags being set because some writers of such a file
> might not set these flags.
https://docs.microsoft.com/en-us/windows/win32/direct3ddds/dds-header
¯\_(ツ)_/¯
Fixes#39516.
0f21249a2d