Fix incorrect comment regarding command completion tags

The comment talked about some Asserts which did not exist and also a
variable name which seems to have long since disappeared.

Rewrite the comment in a way that will hopefully stand the test of
time and inform people why we always write "INSERT 0 <nrows>" instead of
"INSERT <nrows>" in the command completion tag for INSERT.

Reviewed-by: Mark Dilger
Discussion: https://postgr.es/m/CAApHDvpiUg09AvvGAVopNAKemA9z-kCmt7Fi6HKauc32bKzx4w@mail.gmail.com
This commit is contained in:
David Rowley 2022-10-14 14:32:00 +13:00
parent ba185d318d
commit 39b8c293fc

@ -178,17 +178,18 @@ EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_o
/*
* We assume the tagname is plain ASCII and therefore requires no
* encoding conversion.
*
* We no longer display LastOid, but to preserve the wire
* protocol, we write InvalidOid where the LastOid used to be
* written.
*
* All cases where LastOid was written also write nprocessed
* count, so just Assert that rather than having an extra test.
*/
tag = qc->commandTag;
tagname = GetCommandTagName(tag);
/*
* In PostgreSQL versions 11 and earlier, it was possible to
* create a table WITH OIDS. When inserting into such a table,
* INSERT used to include the Oid of the inserted record in the
* completion tag. To maintain compatibility in the wire
* protocol, we now write a "0" (for InvalidOid) in the location
* where we once wrote the new record's Oid.
*/
if (command_tag_display_rowcount(tag) && !force_undecorated_output)
snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
tag == CMDTAG_INSERT ?