Thank you for the reviews Nathan, Michael.
I agree with handling NULL in ShowAllGUCConfig() instead.
I've attached the updated patch.
--
Steve Chavez
Engineering at https://supabase.com/
On Tue, 24 May 2022 at 20:21, Michael Paquier <mich...@paquier.xyz> wrote:
> On Tue, May 24, 2022 at 11:41:49AM -0700, Nathan Bossart wrote:
> > I would actually ERROR on this so that we aren't relying on
> > --enable-cassert builds to catch it. That being said, if there's no
> strong
> > reason to enforce that a short description be provided, then why not
> adjust
> > ShowAllGUCConfig() to set that column to NULL when short_desc is missing?
>
> Well, issuing an ERROR on the stable branches would be troublesome for
> extension developers when reloading after a minor update if they did
> not set their short_desc in a custom GUC. So, while I'd like to
> encourage the use of short_desc, using your suggestion to make the
> code more flexible with NULL is fine by me. GetConfigOptionByNum()
> does that for long_desc by the way, meaning that we also have a
> problem there on a build with --enable-nls for short_desc, no?
> --
> Michael
>
From 7b3d1451938f37d08e692a1f252b2f71c1ae5279 Mon Sep 17 00:00:00 2001
From: Steve Chavez <st...@supabase.io>
Date: Tue, 24 May 2022 23:46:40 -0500
Subject: [PATCH] Handle a NULL short_desc in ShowAllGUCConfig
Prevent a segfault when using a SHOW ALL, in case a DefineCustomXXXVariable()
was defined with a NULL short_desc.
---
src/backend/utils/misc/guc.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 8e9b71375c..d7dd727d45 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -9780,7 +9780,16 @@ ShowAllGUCConfig(DestReceiver *dest)
isnull[1] = true;
}
- values[2] = PointerGetDatum(cstring_to_text(conf->short_desc));
+ if (conf->short_desc)
+ {
+ values[2] = PointerGetDatum(cstring_to_text(conf->short_desc));
+ isnull[2] = false;
+ }
+ else
+ {
+ values[2] = PointerGetDatum(NULL);
+ isnull[2] = true;
+ }
/* send it to dest */
do_tup_output(tstate, values, isnull);
@@ -9792,7 +9801,10 @@ ShowAllGUCConfig(DestReceiver *dest)
pfree(setting);
pfree(DatumGetPointer(values[1]));
}
- pfree(DatumGetPointer(values[2]));
+ if (conf->short_desc)
+ {
+ pfree(DatumGetPointer(values[2]));
+ }
}
end_tup_output(tstate);
--
2.32.0
