Horton

Re: Converting tab-complete.c's else-if chain to a switch

Daniel Gustafsson <daniel@yesql.se>

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From: Daniel Gustafsson <daniel@yesql.se>
To: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Thomas Munro <thomas.munro@gmail.com>, Andres Freund <andres@anarazel.de>, pgsql-hackers@lists.postgresql.org
Date: 2024-10-10T07:30:41Z
Lists: pgsql-hackers 
> On 10 Oct 2024, at 09:22, Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com> wrote:

> psql tries to read the previous word when matches are NULL. However,
> there's no previous word set here, leading to the segfault.
> 
> I've attached a patch that checks if the previous word does exist
> before trying to use it, along with an additional test for this
> codepath.

Nice, I was just typing up an email with the same fix when your landed in my
inbox after having ended up with a segfaulting psql testing a patch.  (I didn't
include a test though so yours is better.) From reading the code I agree that
we must check previous_words_count here so +1 on this patch.

--
Daniel Gustafsson

Commits

  1. Don't hard-code the input file name in gen_tabcomplete.pl's output.

  2. Avoid possible segfault in psql's tab completion.

  3. Convert tab-complete's long else-if chain to a switch statement.

  4. Prepare tab-complete.c for preprocessing.

  5. Invent "MatchAnyN" option for tab-complete.c's Matches/MatchesCS.