From f1431f3bffa00962ae8debb98a750ed2fb09fa3b Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Sat, 28 May 2022 12:12:40 +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 | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 8e9b71375c..55d41ae7d6 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 +9801,8 @@ 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); @@ -10002,7 +10012,7 @@ GetConfigOptionByNum(int varnum, const char **values, bool *noshow) values[3] = _(config_group_names[conf->group]); /* short_desc */ - values[4] = _(conf->short_desc); + values[4] = conf->short_desc != NULL ? _(conf->short_desc) : NULL; /* extra_desc */ values[5] = conf->long_desc != NULL ? _(conf->long_desc) : NULL;