wined3d: in surface Blt when source and destination are not the same only lock the part of the destination surface that is requested to copy to.

[H. Verbeet]

2008/7/28 Aric Stewart <aric at codeweavers.com>:
> I am unsure if you are thinking i should be concerned about the mirrored or
> flipped destinations as i will admit I have no idea what that entails.
>
I seem to remember that Blt allowed top > bottom and left > right in
the source and destination rectangles, in order to support flipping or
mirroring the image data. LockRect can't handle that though, so you'd
have to make sure the rectangle you pass to LockRect has (left, top)
as the top left corner. Right now I can't seem to find the code
handling that though, so maybe it's not an issue.