[PATCH v7 05/10] pkt-line: add packet_write_gently()

[larsxschneider@gmail.com]

From: Lars Schneider <larsxschneider@gmail.com>

packet_write_fmt_gently() uses format_packet() which lets the caller
only send string data via "%s". That means it cannot be used for
arbitrary data that may contain NULs.

Add packet_write_gently() which writes arbitrary data and returns `0`
for success and `-1` for an error. This function is used by other
pkt-line functions in a subsequent patch.

Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
---
 pkt-line.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/pkt-line.c b/pkt-line.c
index 37345ca..1d3d725 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -181,6 +181,25 @@ int packet_write_fmt_gently(int fd, const char *fmt, ...)
 	return status;
 }
 
+int packet_write_gently(const int fd_out, const char *buf, size_t size)
+{
+	static char packet_write_buffer[LARGE_PACKET_MAX];
+
+	if (size > sizeof(packet_write_buffer) - 4) {
+		error("packet write failed");
+		return -1;
+	}
+	packet_trace(buf, size, 1);
+	size += 4;
+	set_packet_header(packet_write_buffer, size);
+	memcpy(packet_write_buffer + 4, buf, size - 4);
+	if (write_in_full(fd_out, packet_write_buffer, size) == size)
+		return 0;
+
+	error("packet write failed");
+	return -1;
+}
+
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 {
 	va_list args;
-- 
2.10.0