Bug#247848: tetex-bin: xdvi: large numerical prefixes lead to integer overflow

[Stefan Ulrich <stefan-ulrich.nntp@zen.co.uk>]

Matt Swift <swift@alum.mit.edu> writes:

> In any case, I don't have the full fix, but I have a fix in
> pseudocode, if someone else figures out how to define the portable C
> MAXINT magical constant.

> (Hi Stefan -- yes, this problem is still there in xdvi 22.82.1-cvs1.
> The code from the Debian version quoted below is only slightly
> different: no "static" number and no #if TOOLKIT.  I submit the bug to
> Debian because I hope a Debian person can supply the part I don't know
> how to write and submit a real patch upstream.)

Thanks very much for the suggestions; I've added them to the
xdvik CVS (xdvik-22.83-CVS2).


>   if (  (number <  MAXINT_QUOT) || \
>        ((number == MAXINT_QUOT) && (digit <= MAXINT_MOD)) ) {
>     number = number * 10 + digit;
>   }
>   else {
>     number = MAXINT;  /* maybe not wise because not what the user requested */
>     WARNING_NUMBER_HAS_GOTTEN_TOO_LARGE();

here I went for giving a warning and not changing the current value.

>   }

> I have not checked the above code carefully for off-by-one errors at
> boundary conditions!

looks OK to me ;-)

Best,
Stefan