1 files changed, 76 insertions, 0 deletions
diff --git a/tests/tail-2/tail-n0f b/tests/tail-2/tail-n0f
new file mode 100755
index 0000000..298fca4
--- /dev/null
+++ b/tests/tail-2/tail-n0f
@@ -0,0 +1,76 @@
+#!/bin/sh
+# Make sure that `tail -n0 -f' and `tail -c0 -f' sleep
+# rather than doing what amounted to a busy-wait.
+
+# Copyright (C) 2003, 2006 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 2 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, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301, USA.
+
+
+# This bug was fixed for 5.0.91
+# It skips the test if your system lacks a /proc/$pid/status
+# file, or if its contents don't look right.
+
+if test "$VERBOSE" = yes; then
+  set -x
+  tail --version
+fi
+
+sleep 2 &
+pid=$!
+sleep .5
+grep '^State:[	 ]*[S]' /proc/$pid/status > /dev/null 2>&1 || \
+  {
+    echo "$0:/proc/$pid/status: missing or 'different': skipping this test" 1>&2
+    (exit 77); exit 77
+  }
+kill $pid
+
+pwd=`pwd`
+t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$
+trap 'status=$?; cd "$pwd" && chmod -R u+rwx $t0 && rm -rf $t0 && exit $status' 0
+trap '(exit $?); exit $?' 1 2 13 15
+
+framework_failure=0
+mkdir -p $tmp || framework_failure=1
+cd $tmp || framework_failure=1
+touch empty || framework_failure=1
+echo anything > nonempty || framework_failure=1
+
+if test $framework_failure = 1; then
+  echo "$0: failure in testing framework" 1>&2
+  (exit 1); exit 1
+fi
+
+fail=0
+
+for file in empty nonempty; do
+  for c_or_n in c n; do
+    tail --sleep=4 -${c_or_n} 0 -f $file &
+    pid=$!
+    sleep .5
+    set _ `sed -n '/^State:[	 ]*\([^	 ]\)/s//\1/p' /proc/$pid/status`
+    shift # Remove the leading `_'.
+    state=$1
+    case $state in
+      S*) ;;
+      *) echo $0: process in unexpected state: $state 1>&2; fail=1 ;;
+    esac
+    kill $pid
+  done
+done
+
+(exit $fail); exit $fail