[l2h] Nesting amsmath constructs align and cases causes infinite loop

[Matthew Saltzman]

I can confirm that this patch does seem to take care of the problem.
Thanks very much for your help.

On Tue, 2014-08-19 at 20:12 +0900, Shigeharu TAKENO wrote: 
> shige 08/19 2014
> ----------------
> 
> | From: Matthew Saltzman <mjs at clemson.edu>
> | To: "shige at iee.niit.ac.jp" <shige at iee.niit.ac.jp>
> | CC: "latex2html at tug.org" <latex2html at tug.org>
> | Subject: Re: [l2h] Nesting amsmath constructs align and cases causes
> |  infinite loop
> =====
> | > It may workaround your problem.
> | 
> | It does indeed solve the problem.  Is it the right solution or just a
> | workaround?
> 
> I find it may be a bug of versions/math.pl. Please apply the 
> patch below.
> 
> ----- From here (patch for math.pl) -----
> --- versions/math.pl.ORG 2004-01-01 15:15:01.000000000 +0900
> +++ versions/math.pl     2014-08-19 20:02:50.828761000 +0900
> @@ -1432,6 +1432,7 @@
>             while ($pre_test =~ s/(($O|$OP)\d+($C|$CP))(.*)\1/$4/) {};
>             $use_all = 1 if ($pre_test=~s/($O|$OP)\d+($C|$CP)//);
>             if (!$use_all) {
> +               $pre_test = $pre_text;
>                 while ($pre_test =~ s/\\begin(($O|$OP)\d+($C|$CP))(.*)\\end\1/$4/){};
>                 $use_all = 1 if ($pre_test=~s/\\(begin|end)($O|$OP)\d+($C|$CP)//);
>             };
> ----- To here (patch for math.pl) -----
> 
> +========================================================+
>  Shigeharu TAKENO     NIigata Institute of Technology
>                        kashiwazaki,Niigata 945-1195 JAPAN
>  shige at iee.niit.ac.jp   TEL(&FAX): +81-257-22-8161
> +========================================================+

-- 
Matthew Saltzman
Clemson University Math Sciences
mjs AT clemson DOT edu