Re: Crash with unmatched patterns

[Thomas Dickey]

On Sat, Jan 11, 2020 at 10:08:56AM -0800, Marc Simpson wrote:
> On Sat, Jan 11, 2020 at 9:58 AM Chris Green <address@hidden> wrote:
> >
> > On Sat, Jan 11, 2020 at 09:36:25AM -0800, Marc Simpson wrote:
> > > Hitting n or N after searching for an unmatched pattern with / or ?
> > > crashes vile.
> > >
> > > To reproduce:
> > >
> > >   /\(
> > >
> > > Vile reports
> > >
> > >   [Bad pattern: unmatched () ]
> > >
> > > which is all well and good.  Then hit
> > >
> > >   n
> > >
> > > to attempt searching again (for the bad pattern); this should
> > > reproduce the crash.
> > >
> > Doesn't happen for me, running version 9.8t on xubuntu.
> >
> > When I hit n after the unmatched one I just see "Search reached bottom
> > without matching patter".
> 
> Thanks for checking Chris.  I'm using the latest snapshot here on
> macOS and OpenBSD.
> 
> I think the issue might be
> 
>   https://github.com/ThomasDickey/vile-snapshots/blob/master/search.c#L819
> 
> which, in the event of failed compilation, doesn't clear apat (used to
> set searchpat in the caller).
> 
> I believe that this means that the pattern exists as far as n and N
> are concerned, even though it's failed to compile:
> 
>   https://github.com/ThomasDickey/vile-snapshots/blob/master/search.c#L179

maybe - but that variable's used for the initial prompted value when
doing another '/' command.

I tried reproducing this with my default (package) build on Debian 8,
and then using address-sanitizer in a one-off build.  With the latter,
(or using valgrind), I'd usually manage to see the problem.
 
> I've only had time for a quick look, so this analysis might be completely off.
> 

-- 
Thomas E. Dickey <address@hidden>
https://invisible-island.net
ftp://ftp.invisible-island.net

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