From 1b40ceea24e61b246a09f9ab42f8e82594a418df Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Sat, 28 May 2022 12:13:02 +0900 Subject: [PATCH] Handle NULL for short descriptions of custom GUC variables If a short description is specified as NULL in one of the various DefineCustomXXXVariable() functions available to external modules to define a custom parameter, SHOW ALL would crash. This change teaches SHOW ALL to properly handle NULL short descriptions, as well as any code paths that manipulate it, to gain in flexibility. Note that help_config.c was already able to do that, when describing a set of GUCs for postgres --describe-config. Author: Steve Chavez Reviewed by: Nathan Bossart, Andres Freund, Michael Paquier, Tom Lane Discussion: https://postgr.es/m/CAGRrpzY6hO-Kmykna_XvsTv8P2DshGiU6G3j8yGao4mk0CqjHA%40mail.gmail.com Backpatch-through: 10 --- src/backend/utils/misc/guc.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 2bd789256bc..d4734cf133e 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -8079,7 +8079,16 @@ 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); @@ -8091,7 +8100,8 @@ 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); -- 2.30.2