[debbugs-tracker] bug#20095: closed (conditional branching)

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Your message dated Sun, 10 May 2015 10:16:05 -0700
with message-id <address@hidden>
and subject line Re: sed conditional branching
has caused the debbugs.gnu.org bug report #20095,
regarding conditional branching
to be marked as done.

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-- 
20095: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=20095
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--- Begin Message --- Subject: conditional branching Date: Thu, 12 Mar 2015 02:42:07 +0000 (UTC)

I'm using sed to verify that a log file is in the correct format, to make it impossible for crafted input to cause any problems in a shell script.

I'm stumped, and the only explanation that I can think of for why my script isn't working is that sed's "t" command is not working properly.

If I comment out any 2 of the 3 main commands, the output is as expected:

• white space stripper always "succeeds", and thus the script jumps to the success section
• curly brace detector jumps to the "success" section if triggered.  otherwise, the t command fails, because there wasn't a substitution in the first place
  
• entry converter succeeds if format of entry is valid, assuming that there isn't any surrounding white space
  

However, if I un-comment all 3 of the main commands, the script doesn't fail when input is invalid.  Instead, it spits out the un-transformed invalid input, as if it was valid.

Am I missing something, or is this a bug?

filesystem-events.log
Description: Text Data

log-filter.sed
Description: Text document

--- End Message ---

> --- Begin Message ---
>
>
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> Subject: 
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> Re: sed conditional branching
>
>
>
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> Date: 
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> Sun, 10 May 2015 10:16:05 -0700
>
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> tags 20095 notabug
> thanks
>
> Davide Brini's analysis at https://debbugs.gnu.org/cgi/bugreport.cgi?bug=20095#8
> is correct. "t" works like this:
>
> 't LABEL'
>      Branch to LABEL only if there has been a successful 's'ubstitution
>      since the last input line was read or conditional branch was taken.
>      The LABEL may be omitted, in which case the next cycle is started.
>
> yet your script expects it to work differently.
>
> Hence, I'm marking this issue as a non-bug and closing it.
> However, you are welcome to reply here; any comments will
> be logged at https://bugs.gnu.org/20095.
>
>
> --- End Message ---