[debbugs-tracker] bug#34769: closed (Bug in emacs 26.1 gdb-send match-string applied after non-matching string-match)

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Your message dated Thu, 07 Mar 2019 17:18:20 +0200
with message-id <address@hidden>
and subject line Re: bug#34769: Bug in emacs 26.1 gdb-send match-string applied 
after non-matching string-match
has caused the debbugs.gnu.org bug report #34769,
regarding Bug in emacs 26.1 gdb-send match-string applied after non-matching 
string-match
to be marked as done.

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34769: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=34769
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> --- Begin Message ---
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> Subject: 
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> Bug in emacs 26.1 gdb-send match-string applied after non-matching string-match
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>
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> Date: 
>
> Wed, 6 Mar 2019 12:27:03 +0100 (CET)
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> Dear Emacs maintainers,
>
> At the end of gdb-send one finds the following lines:
>
>   (let* ((control-command-p (string-match gdb-control-commands-regexp string))
>          (command-arg (match-string 3 string))
>
> It is wrong to call (match-string 3 string) if (string-match 
> gdb-control-commands-regexp string) returned nil.
> The doc of match-string says:
> "Return string of text matched by last search."
> That means match-string only returns sensible results if the last match was 
> successful.
>
> Possible correction:
>
>   (let* ((control-command-p (string-match gdb-control-commands-regexp string))
>          (command-arg (and control-command-p (match-string 3 string)))
>
>
> System info:
> GNU Emacs 26.1 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.22.30) of 
> 2018-05-29
>
> Best regards,
> Tobias
>
>
>
> --- End Message ---
> --- Begin Message ---
>
>
>
> Subject: 
>
> Re: bug#34769: Bug in emacs 26.1 gdb-send match-string applied after non-matching string-match
>
>
>
>
> Date: 
>
> Thu, 07 Mar 2019 17:18:20 +0200
>
>
>
>
> > Date: Wed, 6 Mar 2019 21:10:54 +0100 (CET)
> > From: Tobias Zawada <address@hidden>
> > Cc: address@hidden
> > 
> > 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.
>
>
> --- End Message ---