[PATCH] pkt-line: do not report packet write errors twice

[Matheus Tavares <matheus.bernardino@usp.br>]

On write() errors, packet_write() dies with the same error message that
is already printed by its callee, packet_write_gently(). This produces
an unnecessarily verbose and repetitive output:

error: packet write failed
fatal: packet write failed: <strerror() message>

In addition to that, packet_write_gently() does not always fulfill its
caller expectation that errno will be properly set before a non-zero
return. In particular, that is not the case for a "data exceeds max
packet size" error. So, in this case, packet_write() will call
die_errno() and print a strerror(errno) message that might be totally
unrelated to the actual error.

Fix both those issues by turning packet_write() and
packet_write_gently() into wrappers to a lower level function which is
now responsible to either error() or die() as requested by its caller.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
---
 pkt-line.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/pkt-line.c b/pkt-line.c
index 0194137528..39c9ca4212 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -194,13 +194,18 @@ int packet_write_fmt_gently(int fd, const char *fmt, ...)
 	return status;
 }
 
-static int packet_write_gently(const int fd_out, const char *buf, size_t size)
+static int do_packet_write(const int fd_out, const char *buf, size_t size,
+			   int gentle)
 {
 	char header[4];
 	size_t packet_size;
 
-	if (size > LARGE_PACKET_DATA_MAX)
-		return error(_("packet write failed - data exceeds max packet size"));
+	if (size > LARGE_PACKET_DATA_MAX) {
+		if (gentle)
+			return error(_("packet write failed - data exceeds max packet size"));
+		else
+			die(_("packet write failed - data exceeds max packet size"));
+	}
 
 	packet_trace(buf, size, 1);
 	packet_size = size + 4;
@@ -215,15 +220,23 @@ static int packet_write_gently(const int fd_out, const char *buf, size_t size)
 	 */
 
 	if (write_in_full(fd_out, header, 4) < 0 ||
-	    write_in_full(fd_out, buf, size) < 0)
-		return error(_("packet write failed"));
+	    write_in_full(fd_out, buf, size) < 0) {
+		if (gentle)
+			return error_errno(_("packet write failed"));
+		else
+			die_errno(_("packet write failed"));
+	}
 	return 0;
 }
 
+static int packet_write_gently(const int fd_out, const char *buf, size_t size)
+{
+	return do_packet_write(fd_out, buf, size, 1);
+}
+
 void packet_write(int fd_out, const char *buf, size_t size)
 {
-	if (packet_write_gently(fd_out, buf, size))
-		die_errno(_("packet write failed"));
+	do_packet_write(fd_out, buf, size, 0);
 }
 
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
-- 
2.30.1