[PATCH] user32: Allow WM_CAPTURECHANGED indicating SetCapture() parameter

[Ken Thomases]

On Jan 31, 2016, at 7:18 PM, Christopher Thielen <cthielen at gmail.com> wrote:
> 
> A window may be notified with WM_CAPTURECHANGED about itself
> gaining mouse capture if it calls SetCapture() twice.
> 
> Tested on Windows XP and Fedora Workstation 22.
> 
> Revised to simplify based on wine-devel feedback.
> Revised to address any side-effects of new WM_CAPTURECHANGED
> messages.

The changes to comctl32 should be in a separate patch.  In general, changes to different DLLs should be in separate patches unless it can't be avoided.  The comctl32 patch should come before the change to when WM_CAPTURECHANGED is sent so that things aren't broken part-way through the patch series.  You might also put the button.c changes in a separate patch, too.

>  	case WM_CAPTURECHANGED:
> -	    return TOOLBAR_CaptureChanged(infoPtr);
> +	    if(hwnd != lParam)
> +	    {
> +	        return TOOLBAR_CaptureChanged(infoPtr);
> +	    }
> +	    else
> +	    {
> +	        return 0;
> +	    }

The second return can be hoisted out of the else since the true branch can't fall through.  Also, you can reverse the logic, so the code can look like:

    case WM_CAPTURECHANGED:
        if(hwnd == lParam)
            return 0;
        return TOOLBAR_CaptureChanged(infoPtr);

I think that's clearer and also a smaller diff.  Same for the other files.

Cheers,
Ken