Re: [PATCH 0/2] MR8327: comctl32/listview: Always set the initial background mode to TRANSPARENT.

[Nikolay Sivov (＠nsivov)]

Nikolay Sivov (@nsivov) commented about dlls/comctl32/listview.c:
>  GetClientRect(infoPtr->hwndSelf, &rcClient);
>  customdraw_fill(&nmlvcd, infoPtr, hdc, &rcClient, 0);
> - /* v5 sets the initial background mix mode to TRANSPARENT while v6 uses OPAQUE. */
> - SetBkMode(hdc, TRANSPARENT);
> cdmode = notify_customdraw(infoPtr, CDDS_PREPAINT, &nmlvcd);
> if (cdmode & CDRF_SKIPDEFAULT) goto enddraw;

I don't think we can do that unconditionally, a lot of application were never tested with v5 and very likely depend on such differences. I know that we don't run some of the painting tests on v6 at the moment. Splitting them up and having a separate test for background mode that runs on v5 and v6 is what we should do.

We might do a separate v6 build in theory, but I suspect that will be avoided for as long as possible. It should be enough to check for windows class in current context in WM_NCCREATE (and maybe for actual class name too if it's possible to use versioned name directly, I don't remember).