sed -i: don't leave behind a temporary sedXXXXXX file

For example, running a command like "sed -i s//b/ F" would fail
to remove a temporary file named sedXXXXXX (for random XXXXXX)
in the directory alongside F.
* sed/sed.c (G_file_to_unlink): New global.
(register_cleanup_file, cancel_cleanup, cleanup): New functions.
(main): Call atexit.
* sed/execute.c (open_next_file): Register for unlink.
(closedown): Call cancel_cleanup right after the rename.
* sed/sed.h: Declare two of the new functions.
* NEWS (Bug fixes): Mention it.
* testsuite/temp-file-cleanup.sh: New file.  Test for this.
* testsuite/Makefile.am (T): Add it.
Reported by David Jones in http://bugs.gnu.org/20002.

1 files changed, 38 insertions, 0 deletions

diff --git a/testsuite/temp-file-cleanup.sh b/testsuite/temp-file-cleanup.sh
new file mode 100755
index 0000000..02fa91d
--- /dev/null
+++ b/testsuite/temp-file-cleanup.sh
@@ -0,0 +1,38 @@
+#!/bin/sh
+# Verify that an erroneous use of sed -i no longer leaves behind
+# a temporary file.
+
+# Copyright (C) 2015 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 <http://www.gnu.org/licenses/>.
+. "${srcdir=.}/init.sh"; path_prepend_ ../sed
+print_ver_ sed
+
+# The input file must have at least one line.
+echo > in || framework_failure_
+printf 'sed: -e expression #1, char 0: no previous regular expression\n' \
+  > exp || framework_failure_
+
+# Before sed-4.3, this would create a file named sed??????
+sed -i s//b/ in > out 2> err
+test $? = 1 || fail=1
+
+compare /dev/null out || fail=1
+compare exp err || fail=1
+
+# Ensure that no other file has been created in this directory.
+files=$(echo *)
+test "$files" = "err exp in out" || fail=1
+
+Exit $fail