bug#11464: 24.1.50; pos-visible-in-window-p returns a false positive with bidi text

[Michael Welsh Duggan]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Michael Welsh Duggan <mwd@cert.org>
>> Cc: Ari Roponen <ari.roponen@gmail.com>, 11464@debbugs.gnu.org
>> Date: Thu, 17 May 2012 13:56:45 -0400
>> 
>>   else if (top_y < it.last_visible_y) ==> if (255 < 256) ==> if (TRUE)
>> 
>> hence, visible_p _would_ be set to 1 by the else if clause.
>
> And will never be reset to zero, because 27 <= 256 => FALSE.  And yet
> Ari said that he needed to change the condition to <=.

But where do you get 27?  The number was 270, I believe.

>> bottom_y = 270
>> it.last_visible_y = 256
>> top_y = 255
>> window_top_y = 0

-- 
Michael Welsh Duggan
(mwd@cert.org)