Re: [PATCH v5 8/8] convert: Update subprocess_read_status to not die on EOF

[Lars Schneider <larsxschneider@gmail.com>]

> On 07 Apr 2017, at 14:03, Ben Peart <peartben@gmail.com> wrote:
> 
> Enable sub-processes to gracefully handle when the process dies by
> updating subprocess_read_status to return an error on EOF instead of
> dying.
> 
> Update apply_multi_file_filter to take advantage of the revised
> subprocess_read_status.
> 
> Signed-off-by: Ben Peart <benpeart@microsoft.com>
> ---
> convert.c     | 10 ++++++++--
> sub-process.c | 10 +++++++---
> sub-process.h |  2 +-
> 3 files changed, 16 insertions(+), 6 deletions(-)
> 
> diff --git a/convert.c b/convert.c
> index baa41da760..9e181e27ad 100644
> --- a/convert.c
> +++ b/convert.c
> @@ -629,7 +629,10 @@ static int apply_multi_file_filter(const char *path, const char *src, size_t len
> 	if (err)
> 		goto done;
> 
> -	subprocess_read_status(process->out, &filter_status);
> +	err = subprocess_read_status(process->out, &filter_status);
> +	if (err)
> +		goto done;
> +
> 	err = strcmp(filter_status.buf, "success");
> 	if (err)
> 		goto done;
> @@ -638,7 +641,10 @@ static int apply_multi_file_filter(const char *path, const char *src, size_t len
> 	if (err)
> 		goto done;
> 
> -	subprocess_read_status(process->out, &filter_status);
> +	err = subprocess_read_status(process->out, &filter_status);
> +	if (err)
> +		goto done;
> +
> 	err = strcmp(filter_status.buf, "success");
> 
> done:
> diff --git a/sub-process.c b/sub-process.c
> index 60bb650012..c5057cafcd 100644
> --- a/sub-process.c
> +++ b/sub-process.c
> @@ -30,13 +30,15 @@ struct subprocess_entry *subprocess_find_entry(const char *cmd)
> 	return hashmap_get(&subprocess_map, &key, NULL);
> }
> 
> -void subprocess_read_status(int fd, struct strbuf *status)
> +int subprocess_read_status(int fd, struct strbuf *status)
> {
> 	struct strbuf **pair;
> 	char *line;
> +	int len;
> +
> 	for (;;) {
> -		line = packet_read_line(fd, NULL);
> -		if (!line)
> +		len = packet_read_line_gently(fd, NULL, &line);
> +		if ((len == -1) || !line)

Minor nit: Maybe "if ((len < 0) || !line)" ?


> 			break;
> 		pair = strbuf_split_str(line, '=', 2);
> 		if (pair[0] && pair[0]->len && pair[1]) {
> @@ -48,6 +50,8 @@ void subprocess_read_status(int fd, struct strbuf *status)
> 		}
> 		strbuf_list_free(pair);
> 	}
> +
> +	return len == -1 ? len : 0;

Minor nit: Maybe "return len < 0 ? len : 0;

> }
> 
> void subprocess_stop(struct subprocess_entry *entry)
> diff --git a/sub-process.h b/sub-process.h
> index 0cf1760a0a..5a1eeeece0 100644
> --- a/sub-process.h
> +++ b/sub-process.h
> @@ -41,6 +41,6 @@ static inline struct child_process *subprocess_get_child_process(
>  * key/value pairs and return the value from the last "status" packet
>  */
> 
> -void subprocess_read_status(int fd, struct strbuf *status);
> +int subprocess_read_status(int fd, struct strbuf *status);
> 
> #endif
> -- 
> 2.12.0.windows.1.31.g1548525701.dirty
> 

Looks good to me.

Thanks,
Lars