zfs receive: add test to reproduce issue #18344

tests/runfiles/common.run

@@ -900,8 +900,8 @@ tests = ['redacted_compressed', 'redacted_contents', 'redacted_deleted',
     'redacted_disabled_feature', 'redacted_embedded', 'redacted_holes',
     'redacted_incrementals', 'redacted_largeblocks', 'redacted_many_clones',
     'redacted_mixed_recsize', 'redacted_mounts', 'redacted_negative',
-    'redacted_origin', 'redacted_panic', 'redacted_props', 'redacted_resume',
-    'redacted_size', 'redacted_volume']
+    'redacted_opposite_endian', 'redacted_origin', 'redacted_panic',
+    'redacted_props', 'redacted_resume', 'redacted_size', 'redacted_volume']
 tags = ['functional', 'redacted_send']
 
 [tests/functional/raidz]

tests/test-runner/bin/zts-report.py.in

@@ -163,6 +163,7 @@ known = {
     'refreserv/refreserv_004_pos': ['FAIL', known_reason],
     'rootpool/setup': ['SKIP', na_reason],
     'rsend/rsend_008_pos': ['SKIP', 6066],
+    'redacted_send/redacted_opposite_endian': ['FAIL', 18344],
     'vdev_zaps/vdev_zaps_007_pos': ['FAIL', known_reason],
 }
 

tests/zfs-tests/tests/Makefile.am

@@ -359,6 +359,8 @@ nobase_dist_datadir_zfs_tests_tests_DATA += \
 	functional/projectquota/projectquota_common.kshlib \
 	functional/quota/quota.cfg \
 	functional/quota/quota.kshlib \
+	functional/redacted_send/big-endian-redacted.zsend.bz2 \
+	functional/redacted_send/little-endian-redacted.zsend.bz2 \
 	functional/redacted_send/redacted.cfg \
 	functional/redacted_send/redacted.kshlib \
 	functional/redundancy/redundancy.cfg \
@@ -1889,6 +1891,7 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/redacted_send/redacted_mixed_recsize.ksh \
 	functional/redacted_send/redacted_mounts.ksh \
 	functional/redacted_send/redacted_negative.ksh \
+	functional/redacted_send/redacted_opposite_endian.ksh \
 	functional/redacted_send/redacted_origin.ksh \
 	functional/redacted_send/redacted_panic.ksh \
 	functional/redacted_send/redacted_props.ksh \

tests/zfs-tests/tests/functional/redacted_send/redacted_opposite_endian.ksh

@@ -0,0 +1,74 @@
+#!/bin/ksh
+# SPDX-License-Identifier: CDDL-1.0
+
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright (c) 2026, OpenZFS Contributors. All rights reserved.
+#
+
+. $STF_SUITE/tests/functional/redacted_send/redacted.kshlib
+
+#
+# Description:
+# Verify that zfs receive can accept a redacted send stream generated
+# on a system with the opposite byte order.  This is a regression test
+# for GitHub issue #18344, which reports that receiving a redacted stream
+# from an opposite-endian sender fails.
+#
+# Strategy:
+# 1. Determine the endianness of the running system.
+# 2. Select the pre-built redacted send stream from the opposite
+#    endianness.
+# 3. Decompress the stream and attempt to receive it into POOL2.
+# 4. Verify the receive succeeds.
+#
+
+verify_runnable "both"
+
+typeset recvfs="$POOL2/opposite_endian_recv"
+typeset streamdir=$STF_SUITE/tests/functional/redacted_send
+typeset tmpdir="$(get_prop mountpoint $POOL)/tmp"
+typeset sendfile=$(mktemp $tmpdir/stream.XXXX)
+
+function cleanup
+{
+	if datasetexists $recvfs; then
+		destroy_dataset $recvfs "-r"
+	fi
+	rm -f $sendfile
+}
+log_onexit cleanup
+
+log_assert "Receiving a redacted stream from an opposite-endian sender" \
+    "should succeed (issue #18344)"
+
+# Determine system endianness and select the opposite-endian stream.
+typeset native_endian=$(python3 -c "import sys; print(sys.byteorder)")
+if [[ "$native_endian" == "little" ]]; then
+	# System is little-endian; use the big-endian stream.
+	typeset streamfile="$streamdir/big-endian-redacted.zsend.bz2"
+	log_note "System is little-endian, receiving big-endian stream"
+else
+	# System is big-endian; use the little-endian stream.
+	typeset streamfile="$streamdir/little-endian-redacted.zsend.bz2"
+	log_note "System is big-endian, receiving little-endian stream"
+fi
+
+if [[ ! -f "$streamfile" ]]; then
+	log_unsupported "Opposite-endian stream file not found: $streamfile"
+fi
+
+log_must eval "bzcat <$streamfile >$sendfile"
+log_must eval "zfs recv $recvfs <$sendfile"
+
+log_pass "Successfully received opposite-endian redacted stream (issue #18344)"