From: Thomas Munro <tmunro@postgresql.org>
Date: Fri, 6 Jan 2023 03:38:46 +0000 (+1300)
Subject: Fix pg_truncate() on Windows.
X-Git-Tag: REL_15_2~44
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f60acde869985b35146c6f7f941dd571fc88b3c4;p=thirdparty%2Fpostgresql.git

Fix pg_truncate() on Windows.

Commit 57faaf376 added pg_truncate(const char *path, off_t length), but
"length" was ignored under WIN32 and the file was unconditionally
truncated to 0.

There was no live bug, since the only caller passes 0.

Fix, and back-patch to 14 where the function arrived.

Author: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/20230106031652.GR3109%40telsasoft.com
---

diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 24704b6a023..8d7ef91785e 100644
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -649,7 +649,7 @@ pg_truncate(const char *path, off_t length)
 	fd = OpenTransientFile(path, O_RDWR | PG_BINARY);
 	if (fd >= 0)
 	{
-		ret = ftruncate(fd, 0);
+		ret = ftruncate(fd, length);
 		save_errno = errno;
 		CloseTransientFile(fd);
 		errno = save_errno;