--- /dev/null
+#!/bin/sh
+# Ensure an upper-case user-specified suffix works as expected.
+# This test would have failed in gzip-1.18
+
+# Copyright 2017-2018 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/>.
+# limit so don't run it by default.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ..
+
+# Use a suffix of "T":
+:|gzip > kT || framework_failure_
+
+fail=0
+gzip -d -S T kT > out 2> err || fail=1
+
+test -f k || fail=1
+compare /dev/null out || fail=1
+compare /dev/null err || fail=1
+
+Exit $fail