From 4f5995dd983db31bce347411c16ecc7319a2d9af Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 16 Jun 2016 12:17:03 -0400 Subject: [PATCH] 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: <20160615204036.2d35d86a@firost> --- src/backend/postmaster/postmaster.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 7e3fd0d3fd..3cfd5b8a57 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -821,10 +821,14 @@ PostmasterMain(int argc, char *argv[]) if (output_config_variable != NULL) { /* - * permission is handled because the user is reading inside the data - * dir + * "-C guc" was specified, so print GUC's value and exit. No extra + * permission check is needed because the user is reading inside the + * data dir. */ - puts(GetConfigOption(output_config_variable, false, false)); + const char *config_val = GetConfigOption(output_config_variable, + false, false); + + puts(config_val ? config_val : "(null)"); ExitPostmaster(0); }