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From: Ed Maste <emaste@freebsd.org>
Date: Mon, 11 May 2015 15:52:23 -0400
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Subject: Re: Race VT+X11 on -current
To: Hans Petter Selasky <hps@selasky.org>
Cc: Oliver Pinter <oliver.pinter@hardenedbsd.org>, 
 Wolfgang Zenker <wolfgang@lyxys.ka.sub.org>,
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On 10 May 2015 at 13:14, Hans Petter Selasky <hps@selasky.org> wrote:
>
> Your patch is correct from what I can see. Signed modulus can be creepy
> sometimes! Better if VT_MAXWINDOWS was power of two and we used a bitwise
> AND.

The patch is correct, although signedness doesn't come into play. The
unsigned vw_number just wraps to 2^32-1, which is 3 modulo 12.