Checking MINIMUM_VERSION_FOR_WAL_SUMMARIES

[Artur Zakirov]

Hi hackers,

during reading the source code of new incremental backup functionality
I noticed that the following condition can by unintentional:

    /*
     * For newer server versions, likewise create pg_wal/summaries
     */
    if (PQserverVersion(conn) < MINIMUM_VERSION_FOR_WAL_SUMMARIES)
    {
        ...

        if (pg_mkdir_p(summarydir, pg_dir_create_mode) != 0 &&
            errno != EEXIST)
            pg_fatal("could not create directory \"%s\": %m", summarydir);
    }

This is from src/bin/pg_basebackup/pg_basebackup.c.

Is the condition correct? Shouldn't it be ">=". Otherwise the function
will create "/summaries" only for older PostgreSQL versions.

I've attached a patch to fix it in case this is a typo.

-- 
Artur

From 24227fdcad1fbdb67e38537bc1d70f65d9bdab05 Mon Sep 17 00:00:00 2001
From: Artur Zakirov <zaar...@gmail.com>
Date: Fri, 2 Feb 2024 01:04:27 +0100
Subject: [PATCH v1] Fix checking MINIMUM_VERSION_FOR_WAL_SUMMARIES for
 creating pg_wal/summaries directory

---
 src/bin/pg_basebackup/pg_basebackup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 77489af518..62eba4a962 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -700,7 +700,7 @@ StartLogStreamer(char *startpos, uint32 timeline, char *sysidentifier,
 		/*
 		 * For newer server versions, likewise create pg_wal/summaries
 		 */
-		if (PQserverVersion(conn) < MINIMUM_VERSION_FOR_WAL_SUMMARIES)
+		if (PQserverVersion(conn) >= MINIMUM_VERSION_FOR_WAL_SUMMARIES)
 		{
 			char		summarydir[MAXPGPATH];
 
-- 
2.40.1