Jim Meyering wrote:
...
> Thank you for the report.
> In fixing that, I made three changes:
>
> maint: tac: remove sole use of sprintf in favor of stpcpy
> tac: don't misbehave with multiple non-seekable inputs
> tac: don't leak a file descriptor for each non-seekable input
>
> Before the primary bug fix (2/3), tac could leak only one file
> descriptor, because that bug prevented us from opening 2nd and
> subsequent files. But once fixed, it would leak an FD for each "-"
> (or other nonseekable) command line argument.
...
>>From 95fa11b63f0a5c983723f02afa7c5b896e5a0a97 Mon Sep 17 00:00:00 2001
> From: Jim Meyering <meyer...@redhat.com>
> Date: Sun, 16 Oct 2011 12:14:05 +0200
> Subject: [PATCH 3/3] tac: don't leak a file descriptor for each non-seekable
> input
>
> * src/tac.c (tac_nonseekable): Call fclose after each successful
> call to copy_to_temp.
> ---
> src/tac.c | 2 ++
> 1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/src/tac.c b/src/tac.c
> index 2d8d6ea..ebafa18 100644
> --- a/src/tac.c
> +++ b/src/tac.c
> @@ -516,9 +516,11 @@ tac_nonseekable (int input_fd, const char *file)
> {
> if (tac_seekable (fileno (tmp_stream), tmp_file))
> {
> + fclose (tmp_stream);
> free (tmp_file);
> return true;
> }
> + fclose (tmp_stream);
> }
>
> return false;
There was also an error-path leak of "tmp_file", even with the patch
above (which was not pushed). I've adjusted it to fix that, too:
>From 3f468dfce95ae301359511e19b13658f35a90444 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyer...@redhat.com>
Date: Sun, 16 Oct 2011 12:14:05 +0200
Subject: [PATCH] tac: don't leak a file descriptor for each non-seekable
input
* src/tac.c (tac_nonseekable): Call fclose and free tmp_file after
each successful call to copy_to_temp.
---
src/tac.c | 15 ++++++---------
1 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/src/tac.c b/src/tac.c
index 2d8d6ea..13b05fb 100644
--- a/src/tac.c
+++ b/src/tac.c
@@ -512,16 +512,13 @@ tac_nonseekable (int input_fd, const char *file)
{
FILE *tmp_stream;
char *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;
- }
- }
+ if (!copy_to_temp (&tmp_stream, &tmp_file, input_fd, file))
+ return false;
- return false;
+ bool ok = tac_seekable (fileno (tmp_stream), tmp_file);
+ fclose (tmp_stream);
+ free (tmp_file);
+ return ok;
}
/* Print FILE in reverse, copying it to a temporary
--
1.7.7
