Re: Requesting external_pid_file with postgres -C when not initialized lead to coredump

alain radix wrote:
> Hi,
>
> I faced a coredump when reading the value of the parameter
> "external_pid_file" when it was not initialized in postgresql.conf
> This came from the value not being specified to be initialized to en empty
> string in guc.c in the ConfigureNamesString array.
> the behavior can easily been tested with the following commands :
> initdb test
> postgres -D test -C external_pid_file
>
> I faced the problem with version 9.3, 9.5 and 9.6 beta 1
> This seems to come from a long time ago.
>
> I wrote a patch ( with help from Stéphane Schildknecht ) to correct the
> problem with a proper initialization.

This was fixed six days ago in a slightly different manner:

commit 0b0baf26211a98a8593279fa24635bc4dd9ac99d
Author: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
AuthorDate: Thu Jun 16 12:17:03 2016 -0400
CommitDate: Thu Jun 16 12:17:38 2016 -0400

Avoid crash in "postgres -C guc" for a GUC with a null string value.

Emit "(null)" instead, which was the behavior all along on platforms
that don't crash, eg OS X. Per report from Jehan-Guillaume de Rorthais.
Back-patch to 9.2 where -C option was introduced.

Michael Paquier

Report: <20160615204036(dot)2d35d86a(at)firost>

> The patch also removed a useless initialization of cluster_name to save a
> little memory.

Yeah, we could do away with that I suppose.

> So, here is my first patch for PostgreSQL.

Looking forward to further ones,

--
Álvaro Herrera http://www.2ndQuadrant.com/
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