[metapost] Uninitialized variable sometimes causing malformed TFM files

luigi scarso luigi.scarso at gmail.com
Sun Jun 16 16:14:00 CEST 2019


On Sun, Jun 16, 2019 at 3:41 PM Marcel Fabian Krüger <tex at 2krueger.de>
wrote:

> On Wed, Mar 20, 2019 at 08:26:22PM +0100, Marcel Krüger wrote:
> >  ---- On Wed, 20 Mar 2019 19:01:08 +0100 luigi scarso <
> luigi.scarso at gmail.com> wrote ----
> >  >
> >  >
> >  > On Wed, Mar 20, 2019 at 6:54 PM Marcel Krüger <tex at 2krueger.de>
> wrote:
> >  > Thanks. There is one other thing, I do not really know if I would
> describe it as a backward compatibility bug or a feature request:
> >  >
> >  > For non-"scaled" numbersystems, code like
> >  >
> >  > filldraw stroke z1e--z2e;
> >  > (example taken from cmbase.mf, `left_bracket`)
> >  >
> >  > fail, because z1e-- is interpreted as z 1e- - instead of z1e --. So
> z1e--z2e is equal to z1-z2e, leading to lots of errors.
> >  >
> >  > I understand that the new numbersystems and the exponential syntax
> can lead to problems of this kind, but I think this could be avoided:
> >  > Maybe a `e+` / `e-` could only be interpreted as exponential notation
> if it is followed by a  digit? I do not think
> >  > anyone would write "1e-" or "3e+" for 1 or 3, so it should not lead
> to any breakage.
> >  > On the other hand it would catch almost all cases where this is
> invoked accidentially.
> >  >
> >  > A possible implementation of this change  is attached.
> >  >
> >  >
> >  > hm it looks like a serious bug, and I fear I will not able to fix it
> for next TL --- but I hope to put it into trunk immediately after the TL
> code is frozen.
> >  >
> >
> > Right, I am sorry for bringing this up so late in the TL cycle.
> >
> > One additional note on this: The behaviour described above (`1e-` being
> interpreted as `1`) seems to be specific to the `double` mode.
> > The `decimal` mode just fails because it is not able to parse the
> number, which further reduces the risk of breaking some code by changing
> the current
> > behaviour.
> >
> > Also I attached a fixed version of the earlier patch, there was a
> smaller error.
> >
> > Best regards,
> > Marcel Krüger
> >
> >  >
> >  > --
> >  > luigi
> >  >
>
> Hi,
>
> are there still plans to fix this?
>
>
yes


-- 
luigi
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