[tex-live] mf segfault

[Olaf Weber]

Thorsten Dahlheimer writes:
> Nelson H. F. Beebe wrote:

>>>> The example Metafont code uses so many independent variables
>>>> (at least 2^25) that the serial number counter (the serial_no
>>>> variable) overflows and becomes negative. But Metafont's internal
>>>> routines assume that serial numbers are positive.

>> Congratulations!  You've just uncovered a bug in Metafont that Don
>> will very likely fix (but not soon).  You should propose a patch
>> that we can incorporate in TeXlive Metafont releases until Don
>> makes an official change.  If he accepts your bug report (send it
>> to Barbara Beeton, who privately coordinates such things with Don),
>> you'll get a nice check to cash (or frame).

> Ok, I've attached a change file that adds an overflow check
> for serial_no. It will trigger a fatal error if the largest
> possible value has been reached.

FWIW, I've added the proposed code to the metafont and metapost change
files for web2c.

Lots of thanks for tracking this one down.

-- 
Olaf Weber

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