Subject: Re: bug#34769: Bug in emacs 26.1 gdb-send match-string applied after non-matching string-match

From: Eli Zaretskii <[email-masked]>
Date: Thu, 07 Mar 2019 17:18:20 +0200

> Date: Wed, 6 Mar 2019 21:10:54 +0100 (CET)
> From: Tobias Zawada <[email-masked]>
> Cc: [email-masked]
> 
> Dear Eli,
> thanks for looking into this.
> 
> > > It is wrong to call (match-string 3 string) if (string-match gdb-control-commands-regexp string) returned nil.
> > ...
> > That is true, and a cleanup is a good idea. But please note that the
> > undefined results are not used if control-command-p is nil, so the
> > issue is not that serious.
> 
> The match data is that one of the previous successful matching operation.
> One gets an args-out-of-range signal if the indexes in the match data are larger than the width of the string argument to match-string. That is how I discovered the error.

You are right; I've now fixed this on the emacs-26 branch.