[PATCH] sha1-file: release strbuf after use

[PATCH] sha1-file: release strbuf after use

[René Scharfe]

Signed-off-by: René Scharfe <l.s.r@web.de>
---
Patch generated with --function-context for easier review.

The plugged leak was added by a10a17877b (for_each_alternate_ref:
replace transport code with for-each-ref, 2017-02-08) and showed up in
709dfa6990 (object-store.h: move for_each_alternate_ref() from
transport.h, 2019-07-01), where it caught my eye, belatedly.

 sha1-file.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sha1-file.c b/sha1-file.c
index 84fd02f107..487ea35d2d 100644
--- a/sha1-file.c
+++ b/sha1-file.c
@@ -773,32 +773,33 @@ static void fill_alternate_refs_command(struct child_process *cmd,
 static void read_alternate_refs(const char *path,
 				alternate_ref_fn *cb,
 				void *data)
 {
 	struct child_process cmd = CHILD_PROCESS_INIT;
 	struct strbuf line = STRBUF_INIT;
 	FILE *fh;

 	fill_alternate_refs_command(&cmd, path);

 	if (start_command(&cmd))
 		return;

 	fh = xfdopen(cmd.out, "r");
 	while (strbuf_getline_lf(&line, fh) != EOF) {
 		struct object_id oid;
 		const char *p;

 		if (parse_oid_hex(line.buf, &oid, &p) || *p) {
 			warning(_("invalid line while parsing alternate refs: %s"),
 				line.buf);
 			break;
 		}

 		cb(&oid, data);
 	}

 	fclose(fh);
 	finish_command(&cmd);
+	strbuf_release(&line);
 }

 struct alternate_refs_data {
--
2.22.0

Re: [PATCH] sha1-file: release strbuf after use

[Jeff King]

On Wed, Aug 07, 2019 at 01:15:25PM +0200, René Scharfe wrote:

> Signed-off-by: René Scharfe <l.s.r@web.de>
> ---
> Patch generated with --function-context for easier review.
> 
> The plugged leak was added by a10a17877b (for_each_alternate_ref:
> replace transport code with for-each-ref, 2017-02-08) and showed up in
> 709dfa6990 (object-store.h: move for_each_alternate_ref() from
> transport.h, 2019-07-01), where it caught my eye, belatedly.

Thanks, the patch obviously looks good (though I wouldn't be sad for
some of your digging above to go into the commit message).

I had a vague feeling that we had seen this particular leak before (and
presumably the fix fell through the cracks). But I couldn't find it on
the list. I think after a while these strbuf_getline() leaks all start
to look the same. :)

-Peff

Re: [PATCH] sha1-file: release strbuf after use

[Derrick Stolee]

On 8/7/2019 7:15 AM, René Scharfe wrote:
> Signed-off-by: René Scharfe <l.s.r@web.de>
> ---
> Patch generated with --function-context for easier review.

Thanks again. LGTM.

-Stolee