1 files changed, 67 insertions, 0 deletions
diff --git a/tests/tail/pipe-f.sh b/tests/tail/pipe-f.sh
new file mode 100755
index 0000000..46bcbbe
--- /dev/null
+++ b/tests/tail/pipe-f.sh
@@ -0,0 +1,67 @@
+#!/bin/sh
+# ensure that tail -f doesn't hang in various cases
+
+# Copyright (C) 2009-2023 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_ tail test head
+trap_sigpipe_or_skip_
+
+# Speedup the non inotify case
+fastpoll='-s.1 --max-unchanged-stats=1'
+
+for mode in '' '---disable-inotify'; do
+# Ensure :|tail -f doesn't hang, per POSIX
+echo oo > exp || framework_failure_
+echo foo | timeout 10 tail -f $mode $fastpoll -c3 > out || fail=1
+compare exp out || fail=1
+cat <<\EOF > exp || framework_failure_
+==> standard input <==
+ar
+EOF
+echo bar | returns_ 1 \
+ timeout 10 tail -f $mode $fastpoll -c3 - missing > out || fail=1
+compare exp out || fail=1
+
+# This would wait indefinitely before v8.28 due to no EPIPE being
+# generated due to no data written after the first small amount.
+# Also check tail exits if SIGPIPE is being ignored.
+# Note 'trap - SIGPIPE' is ineffective if the initiating shell
+# has ignored SIGPIPE, but that's not the normal case.
+case $host_triplet in
+  *aix*) echo  'avoiding due to no way to detect closed outputs on AIX' ;;
+  *)
+for disposition in '' '-'; do
+  (trap "$disposition" PIPE;
+   returns_ 124 timeout 10 \
+    tail -n2 -f $mode $fastpoll out && touch timed_out) |
+  head -n2 > out2
+  test -e timed_out && fail=1
+  compare exp out2 || fail=1
+  rm -f timed_out
+done ;;
+esac
+
+# This would wait indefinitely before v8.28 (until first write)
+# test -w /dev/stdout is used to check that >&- is effective
+# which was seen not to be the case on NetBSD 7.1 / x86_64:
+if env test -w /dev/stdout >/dev/null &&
+   env test ! -w /dev/stdout >&-; then
+  (returns_ 1 timeout 10 tail -f $mode $fastpoll /dev/null >&-) || fail=1
+fi
+done
+
+Exit $fail