add missing PQfinish() calls to vacuumdb

[Nathan Bossart]

I noticed that vacuum_one_database() doesn't call PQfinish() before
pg_fatal() in a few of the server version checks.  I seem to have
unintentionally established this precedent in commit 00d1e88.  Michael
claimed to have fixed it before committing [0], but that seems to have been
missed, too.  I don't think this is a huge problem, but it does seem nicer
to properly close the connection before exiting.  If there are no
objections, I plan to commit and back-patch the attached patch shortly.

[0] https://postgr.es/m/20190108020300.GH22498%40paquier.xyz

-- 
nathan

>From be653f97707929e6b7767dc41b34c14c8b9a798b Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nat...@postgresql.org>
Date: Tue, 4 Feb 2025 10:24:09 -0600
Subject: [PATCH v1 1/1] vacuumdb: Add missing PQfinish() calls to
 vacuum_one_database().

---
 src/bin/scripts/vacuumdb.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/bin/scripts/vacuumdb.c b/src/bin/scripts/vacuumdb.c
index 3dc428674ae..74fbc7ef033 100644
--- a/src/bin/scripts/vacuumdb.c
+++ b/src/bin/scripts/vacuumdb.c
@@ -557,20 +557,32 @@ vacuum_one_database(ConnParams *cparams,
        }
 
        if (vacopts->min_xid_age != 0 && PQserverVersion(conn) < 90600)
+       {
+               PQfinish(conn);
                pg_fatal("cannot use the \"%s\" option on server versions older 
than PostgreSQL %s",
                                 "--min-xid-age", "9.6");
+       }
 
        if (vacopts->min_mxid_age != 0 && PQserverVersion(conn) < 90600)
+       {
+               PQfinish(conn);
                pg_fatal("cannot use the \"%s\" option on server versions older 
than PostgreSQL %s",
                                 "--min-mxid-age", "9.6");
+       }
 
        if (vacopts->parallel_workers >= 0 && PQserverVersion(conn) < 130000)
+       {
+               PQfinish(conn);
                pg_fatal("cannot use the \"%s\" option on server versions older 
than PostgreSQL %s",
                                 "--parallel", "13");
+       }
 
        if (vacopts->buffer_usage_limit && PQserverVersion(conn) < 160000)
+       {
+               PQfinish(conn);
                pg_fatal("cannot use the \"%s\" option on server versions older 
than PostgreSQL %s",
                                 "--buffer-usage-limit", "16");
+       }
 
        /* skip_database_stats is used automatically if server supports it */
        vacopts->skip_database_stats = (PQserverVersion(conn) >= 160000);
-- 
2.39.5 (Apple Git-154)