From 14d24f7a530f587099057fa5411ebcf3cfc55e7d Mon Sep 17 00:00:00 2001
From: =?utf8?q?P=C3=A1draig=20Brady?= <P@draigBrady.com>
Date: Thu, 23 Oct 2025 15:25:14 +0100
Subject: [PATCH] tests: date: test --reference

* tests/date/reference.sh: Ensure the -r option is tested.
* tests/local.mk: Add the test.
---
 tests/date/reference.sh | 50 +++++++++++++++++++++++++++++++++++++++++
 tests/local.mk          |  1 +
 2 files changed, 51 insertions(+)
 create mode 100755 tests/date/reference.sh

diff --git a/tests/date/reference.sh b/tests/date/reference.sh
new file mode 100755
index 0000000000..f7db9fd5b1
--- /dev/null
+++ b/tests/date/reference.sh
@@ -0,0 +1,50 @@
+#!/bin/sh
+# Test date --reference
+
+# Copyright (C) 2025 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ date
+
+# Avoid any possible glitches due to daylight-saving changes near the
+# timestamps used during the test.
+TZ=UTC0
+export TZ
+
+t1='2025-10-23 03:00'
+t2='2025-10-23 04:00'
+
+# date(1) only considers modiication time
+touch -m -d "$t1" a || framework_failure_
+touch -m -d "$t2" b || framework_failure_
+
+test $(date +%s -r a) -lt $(date +%s -r b) || fail=1
+
+if test "$(date +%s -d "$t1")" -lt "$(date +%s)"; then
+  test "$(date +%s -r a)" -lt "$(date +%s)" || fail=1
+fi
+
+ln -s t1 t1s || framework_failure_
+if ! test t1 -ot t1s && ! test t1 -nt t1s; then
+  test "$(date -r t1)" = "$(date -r t1s)" || fail=1
+fi
+
+returns_ 1 date --reference || fail=1
+returns_ 1 date --reference= || fail=1
+returns_ 1 date --reference=missing || fail=1
+returns_ 1 date -d "$t1" -r/ || fail=1
+
+Exit $fail
diff --git a/tests/local.mk b/tests/local.mk
index bd7d602aa4..b31346a5c6 100644
--- a/tests/local.mk
+++ b/tests/local.mk
@@ -318,6 +318,7 @@ all_tests =					\
   tests/date/date-ethiopia.sh			\
   tests/date/date-iran.sh			\
   tests/date/date-locale-hour.sh		\
+  tests/date/reference.sh			\
   tests/date/date-sec.sh			\
   tests/date/date-thailand.sh			\
   tests/date/date-tz.sh				\
-- 
2.47.3