From 537f9da37fa396af72d8b3e6af274e0bcbeab794 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Sun, 16 Oct 2011 12:07:05 +0200 Subject: tac: don't misbehave with multiple non-seekable inputs * src/tac.c (copy_to_temp): Do not reuse the template buffer. Instead, scribble only on a freshly-xstrdup'd copy each time. Free that buffer both here, upon failure, and ... (tac_nonseekable): ...free the buffer in caller, upon success. * tests/misc/tac-2-nonseekable: New file. * tests/Makefile.am (TESTS): Add it. * NEWS (Bug fixes): Mention it. Reported by Ambrose Feinstein in http://debbugs.gnu.org/9762. --- src/tac.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'src') diff --git a/src/tac.c b/src/tac.c index 16b918303..2898199a2 100644 --- a/src/tac.c +++ b/src/tac.c @@ -447,12 +447,13 @@ copy_to_temp (FILE **g_tmp, char **g_tempfile, int input_fd, char const *file) FIXME: clean up upon fatal signal. Don't block them, in case $TMPFILE is a remote file system. */ - char *tempfile = template; - int fd = mkstemp (template); + char *tempfile = xstrdup (template); + int fd = mkstemp (tempfile); if (fd < 0) { error (0, errno, _("cannot create temporary file in %s"), quote (tempdir)); + free (tempfile); return false; } @@ -462,6 +463,7 @@ copy_to_temp (FILE **g_tmp, char **g_tempfile, int input_fd, char const *file) error (0, errno, _("cannot open %s for writing"), quote (tempfile)); close (fd); unlink (tempfile); + free (tempfile); return false; } @@ -497,6 +499,7 @@ copy_to_temp (FILE **g_tmp, char **g_tempfile, int input_fd, char const *file) Fail: fclose (tmp); + free (tempfile); return false; } @@ -508,8 +511,16 @@ tac_nonseekable (int input_fd, const char *file) { FILE *tmp_stream; char *tmp_file; - return (copy_to_temp (&tmp_stream, &tmp_file, input_fd, file) - && tac_seekable (fileno (tmp_stream), tmp_file)); + if (copy_to_temp (&tmp_stream, &tmp_file, input_fd, file)) + { + if (tac_seekable (fileno (tmp_stream), tmp_file)) + { + free (tmp_file); + return true; + } + } + + return false; } /* Print FILE in reverse, copying it to a temporary -- cgit v1.2.3-70-g09d2