issue in pgfdw_report_error()?

Fujii Masao <masao.fujii@oss.nttdata.com>

From: Fujii Masao <masao.fujii@oss.nttdata.com>
To: pgsql-hackers@lists.postgresql.org
Date: 2021-11-19T08:18:22Z
Lists: pgsql-hackers
Hi,

pgfdw_report_error() in postgres_fdw is implemented to report the message
"could not obtain ..." if message_primary is NULL as follows.
But, just before this ereport(), message_primary is set to
pchomp(PQerrorMessage()) if it's NULL. So ISTM that message_primary is
always not NULL in ereport() and the message "could not obtain ..." is
never reported. Is this a bug?

-------------------
if (message_primary == NULL)
	message_primary = pchomp(PQerrorMessage(conn));

ereport(elevel,
		(errcode(sqlstate),
		 message_primary ? errmsg_internal("%s", message_primary) :
		 errmsg("could not obtain message string for remote error"),
-------------------


If this is a bug, IMO the following change needs to be applied. Thought?

-------------------
                 ereport(elevel,
                                 (errcode(sqlstate),
-                                message_primary ? errmsg_internal("%s", message_primary) :
+                                (message_primary != NULL && message_primary[0] != '\0') ?
+                                errmsg_internal("%s", message_primary) :
                                  errmsg("could not obtain message string for remote error"),
-------------------

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION



Commits

  1. postgres_fdw: Fix unexpected reporting of empty message.