[PATCH] am: release strbuf after use in split_mail_mbox()

[PATCH] am: release strbuf after use in split_mail_mbox()

[René Scharfe]

Signed-off-by: Rene Scharfe <l.s.r@web.de>
---
 builtin/am.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/builtin/am.c b/builtin/am.c
index 02853b3e05..1ac044da2e 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -708,6 +708,7 @@ static int split_mail_mbox(struct am_state *state, const char **paths,
 {
 	struct child_process cp = CHILD_PROCESS_INIT;
 	struct strbuf last = STRBUF_INIT;
+	int ret;
 
 	cp.git_cmd = 1;
 	argv_array_push(&cp.args, "mailsplit");
@@ -721,13 +722,16 @@ static int split_mail_mbox(struct am_state *state, const char **paths,
 	argv_array_push(&cp.args, "--");
 	argv_array_pushv(&cp.args, paths);
 
-	if (capture_command(&cp, &last, 8))
-		return -1;
+	ret = capture_command(&cp, &last, 8);
+	if (ret)
+		goto exit;
 
 	state->cur = 1;
 	state->last = strtol(last.buf, NULL, 10);
 
-	return 0;
+exit:
+	strbuf_release(&last);
+	return ret ? -1 : 0;
 }
 
 /**
-- 
2.15.1

Re: [PATCH] am: release strbuf after use in split_mail_mbox()

[Jeff King]

On Thu, Dec 07, 2017 at 09:20:19PM +0100, René Scharfe wrote:

> Signed-off-by: Rene Scharfe <l.s.r@web.de>
> ---
>  builtin/am.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/builtin/am.c b/builtin/am.c
> index 02853b3e05..1ac044da2e 100644
> --- a/builtin/am.c
> +++ b/builtin/am.c
> @@ -708,6 +708,7 @@ static int split_mail_mbox(struct am_state *state, const char **paths,
>  {
>  	struct child_process cp = CHILD_PROCESS_INIT;
>  	struct strbuf last = STRBUF_INIT;
> +	int ret;
>  
>  	cp.git_cmd = 1;
>  	argv_array_push(&cp.args, "mailsplit");
> @@ -721,13 +722,16 @@ static int split_mail_mbox(struct am_state *state, const char **paths,
>  	argv_array_push(&cp.args, "--");
>  	argv_array_pushv(&cp.args, paths);
>  
> -	if (capture_command(&cp, &last, 8))
> -		return -1;
> +	ret = capture_command(&cp, &last, 8);
> +	if (ret)
> +		goto exit;

Looks good to me.

Coupled with your third patch, it made me wonder if capture_command()
should free the strbuf when it sees an error. But probably not. Some
callers would want to see the output even from a failing command (and
doubly for pipe_command(), which may capture stderr).

(And anyway, it wouldn't make this case any simpler; we were leaking in
the success code path, too!)

-Peff