Puzzle about ExtSelectClipRgn?

[Thomas Faber]

On 2014-12-03 03:36, Changhui Liu wrote:
> Dear all, I test this code :
>
>
> void test (HDC hdc, HRGN hregion)
> {
>      RECT srcbox;
>      RECT dstbox;
>
>
>      GetClipBox(hdc, &dstbox);
>      GetRgnBox(hregion, &srcbox);
>
>
>      TRACE("Before ExtSelectClipRgn:%s,%s\n",
>              wine_dbgstr_rect(&srcbox), wine_dbgstr_rect(&dstbox) );
>
>
>      ExtSelectClipRgn(hdc, hregion, RGN_AND );
>
>      GetClipBox(graphics->hdc,&dstbox);
>
>      TRACE("After ExtSelectClipRgn:%s,%s\n", wine_dbgstr_rect(&dstbox) );

The second %s here will print random memory.


> }
>
>
> It output in wine is :
> Before ExtSelectClipRgn:(693,5)-(763,28),(693,5)-(763,28)
> After ExtSelectClipRgn:(693,5)-(693,5)
>
>
> But I think it should be output:
> Before ExtSelectClipRgn:(693,5)-(763,28),(693,5)-(763,28)
> After ExtSelectClipRgn:(693,5)-(763,28)
>
>
> Where is my understanding mistake, or is it a bug in ExtSelectClipRgn?