[PATCH 5/7] pkt-line: check write_in_full() errors against "< 0"

[Jeff King]

As with the previous two commits, we prefer to check
write_in_full()'s return value to see if it is negative,
rather than comparing it to the input length.

These cases actually flip the logic to check for success,
making conversion a little different than in other cases. We
could of course write:

  if (write_in_full(...) >= 0)
          return 0;
  return error(...);

But our usual method of spelling write() error checks is
just "< 0". So let's flip the logic for each of these
conditionals to our usual style.

Signed-off-by: Jeff King <p...@peff.net>
---
This will have a minor textual conflict with ma/pkt-line-leakfix which
hasn't quite made it into master yet. The resolution should be
straight-forward, though.

 pkt-line.c | 29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)

diff --git a/pkt-line.c b/pkt-line.c
index 7db9119573..4823d3bb9d 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -94,9 +94,9 @@ void packet_flush(int fd)
 int packet_flush_gently(int fd)
 {
        packet_trace("0000", 4, 1);
-       if (write_in_full(fd, "0000", 4) == 4)
-               return 0;
-       return error("flush packet write failed");
+       if (write_in_full(fd, "0000", 4) < 0)
+               return error("flush packet write failed");
+       return 0;
 }
 
 void packet_buf_flush(struct strbuf *buf)
@@ -137,18 +137,17 @@ static int packet_write_fmt_1(int fd, int gently,
                              const char *fmt, va_list args)
 {
        struct strbuf buf = STRBUF_INIT;
-       ssize_t count;
 
        format_packet(&buf, fmt, args);
-       count = write_in_full(fd, buf.buf, buf.len);
-       if (count == buf.len)
-               return 0;
-
-       if (!gently) {
-               check_pipe(errno);
-               die_errno("packet write with format failed");
+       if (write_in_full(fd, buf.buf, buf.len) < 0) {
+               if (!gently) {
+                       check_pipe(errno);
+                       die_errno("packet write with format failed");
+               }
+               return error("packet write with format failed");
        }
-       return error("packet write with format failed");
+
+       return 0;
 }
 
 void packet_write_fmt(int fd, const char *fmt, ...)
@@ -183,9 +182,9 @@ static int packet_write_gently(const int fd_out, const char 
*buf, size_t size)
        packet_size = size + 4;
        set_packet_header(packet_write_buffer, packet_size);
        memcpy(packet_write_buffer + 4, buf, size);
-       if (write_in_full(fd_out, packet_write_buffer, packet_size) == 
packet_size)
-               return 0;
-       return error("packet write failed");
+       if (write_in_full(fd_out, packet_write_buffer, packet_size) < 0)
+               return error("packet write failed");
+       return 0;
 }
 
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
-- 
2.14.1.874.ge7b2e05270