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

On 07 Apr 2017, at 14:03, Ben Peart [off-list ref] 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 <redacted>
---
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)

			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;

}

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