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Date: Tue, 17 Mar 2009 10:23:40 +0000
From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
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Subject: Re: [Qemu-devel] r6349 broke Commander Keen 4 ;-(
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To: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>

malc wrote:

> On Mon, 16 Mar 2009, Robert Riebisch wrote:
> 
>> Hi!
>>
>> When running Commander Keen 4 (<ftp://ftp.3drealms.com/share/4keen.zip>)
>> in DOS only the left half of the VGA screen is shown on the SDL interface.
>>
>> By doing lots of builds I narrowed the problem down to
>> <http://svn.savannah.gnu.org/viewvc?view=rev&root=qemu&revision=6349> by
>> Stefano Stabellini.
> 
> 6349 is indeed what broke stuff, the code was moved (why?) and uses
> disp_width that could be modified later..

Good catch! Thanks to Robert Riebisch for the extremely good bug report.

The code was moved because the DisplaySurface color depth could change
as a consequence of qemu_create_displaysurface_from or
qemu_console_resize: rgb_to_pixel depends on the DysplaySurface depth
and update_palette[16,256] depends on rgb_to_pixel.
Therefore your patch is fine because fixes the problem keeping the
benefit of the original patch.