[PATCH v5 05/15] pkt-line: add packet_write_gently_fmt()

[larsxschneider@gmail.com]

From: Lars Schneider <larsxschneider@gmail.com>

packet_write() would die in case of a write error even though for some callers
an error would be acceptable. Add packet_write_gently_fmt() which writes a
formatted pkt-line and returns `0` for success and `-1` for an error.

Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
---
 pkt-line.c | 13 +++++++++++++
 pkt-line.h |  1 +
 2 files changed, 14 insertions(+)

diff --git a/pkt-line.c b/pkt-line.c
index 4f25748..a8207dd 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -142,6 +142,19 @@ void packet_write(int fd, const char *fmt, ...)
 	write_or_die(fd, buf.buf, buf.len);
 }
 
+int packet_write_gently_fmt(int fd, const char *fmt, ...)
+{
+	static struct strbuf buf = STRBUF_INIT;
+	va_list args;
+
+	strbuf_reset(&buf);
+	va_start(args, fmt);
+	format_packet(1, &buf, fmt, args);
+	va_end(args);
+	packet_trace(buf.buf + 4, buf.len - 4, 1);
+	return (write_in_full(fd, buf.buf, buf.len) == buf.len ? 0 : -1);
+}
+
 int packet_write_gently(const int fd_out, const char *buf, size_t size)
 {
 	if (size > PKTLINE_DATA_MAXLEN)
diff --git a/pkt-line.h b/pkt-line.h
index 88584f1..82676f4 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -23,6 +23,7 @@ void packet_flush(int fd);
 void packet_write(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 void packet_buf_flush(struct strbuf *buf);
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
+int packet_write_gently_fmt(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 
 /*
  * Read a packetized line into the buffer, which must be at least size bytes
-- 
2.9.2