From e5ba545f16e989ac51c38556e727c8c81988c04e Mon Sep 17 00:00:00 2001
From: Lasse Collin <lasse.collin@tukaani.org>
Date: Fri, 9 Feb 2024 23:21:01 +0200
Subject: [PATCH] xzless: Use ||- in LESSOPEN with with "less" 451 and newer.

(cherry picked from commit 9860d418d296eb3c721e5384fb367c0499b579c8)
---
 src/scripts/xzless.in | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/scripts/xzless.in b/src/scripts/xzless.in
index 93a415d7..53650ef1 100644
--- a/src/scripts/xzless.in
+++ b/src/scripts/xzless.in
@@ -48,7 +48,14 @@ if test "${LESSMETACHARS+set}" != set; then
 fi
 
 VER=$(less -V | { read _ ver _ && echo ${ver%%.*}; })
-if test "$VER" -ge 429; then
+if test "$VER" -ge 451; then
+	# less 451 or later: If the compressed file is valid but has
+	# zero bytes of uncompressed data, using two vertical bars ||- makes
+	# "less" check the exit status of xz and if it is zero then display
+	# an empty file. With a single vertical bar |- and no output from xz,
+	# "less" would attempt to display the raw input file instead.
+	LESSOPEN="||-$xz -cdfqQ -- %s"
+elif test "$VER" -ge 429; then
 	# less 429 or later: LESSOPEN pipe will be used on
 	# standard input if $LESSOPEN begins with |-.
 	LESSOPEN="|-$xz -cdfqQ -- %s"