1 files changed, 59 insertions, 0 deletions
diff --git a/src/preproc/preconv/tests/do-not-seek-the-unseekable.sh b/src/preproc/preconv/tests/do-not-seek-the-unseekable.sh
new file mode 100755
index 0000000..2b1142d
--- /dev/null
+++ b/src/preproc/preconv/tests/do-not-seek-the-unseekable.sh
@@ -0,0 +1,59 @@
+#!/bin/sh
+#
+# Copyright (C) 2022 Free Software Foundation, Inc.
+#
+# This file is part of groff.
+#
+# groff 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.
+#
+# groff 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 <http://www.gnu.org/licenses/>.
+#
+
+set -e
+
+preconv="${abs_top_builddir:-.}/preconv"
+
+fail=
+
+wail () {
+    echo FAILED >&2
+    fail=YES
+}
+
+# Scrape debugging output to see if we're skipping unseekable streams.
+# This is fragile, but we don't want to lock the language of diagnostic
+# messages (especially debugging ones).  If this test fails, check the
+# text of the command's debugging output for a mismatch before
+# investigating deeper problems.
+
+echo "testing seekability of file operand '-'" >&2
+output=$(printf '' | "$preconv" -d - 2>&1)
+echo "$output" | grep -q "stream is not seekable" || wail
+
+# /dev/stdin might not exist in a chroot.  Or, if it's not (a symbolic
+# link to) a character special device, the next test will not be valid,
+# as when using GNU Make's `-j` option.
+#
+# Similarly, we must have a controlling terminal.
+test -z "$fail"
+echo "skipping if /dev/stdin is not a character device" >&2
+test -c /dev/stdin || exit 77 # skip
+echo "skipping if there is no controlling terminal" >&2
+test "$(tty)" != "not a tty" || exit 77 # skip
+
+echo "testing seekability of standard input stream" >&2
+output=$(printf '' | "$preconv" -d /dev/stdin 2>&1)
+echo "$output" | grep -q "stream is not seekable" || wail
+
+test -z "$fail"
+
+# vim:set ai et sw=4 ts=4 tw=72: