[PATCH 1/2] fetch: avoid calling write_or_die()

[Jeff King]

The write_or_die() function has one quirk that a caller might not
expect: when it sees EPIPE from the write() call, it translates that
into a death by SIGPIPE. This doesn't change the overall behavior (the
program exits either way), but it does potentially confuse test scripts
looking for a non-signal exit code.

Let's switch away from using write_or_die() in a few code paths, which
will give us more consistent exit codes. It also gives us the
opportunity to write more descriptive error messages, since we have
context that write_or_die() does not.

Note that this won't do much by itself, since we'd typically be killed
by SIGPIPE before write_or_die() even gets a chance to do its thing.
That will be addressed in the next patch.

Signed-off-by: Jeff King <p...@peff.net>
---
 fetch-pack.c | 9 ++++++---
 pkt-line.c   | 6 ++++--
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/fetch-pack.c b/fetch-pack.c
index 812be15d7e..dca249e9d7 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -191,8 +191,10 @@ static void send_request(struct fetch_pack_args *args,
        if (args->stateless_rpc) {
                send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
                packet_flush(fd);
-       } else
-               write_or_die(fd, buf->buf, buf->len);
+       } else {
+               if (write_in_full(fd, buf->buf, buf->len) < 0)
+                       die_errno("unable to write to remote");
+       }
 }
 
 static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
@@ -1163,7 +1165,8 @@ static int send_fetch_request(struct fetch_negotiator 
*negotiator, int fd_out,
 
        /* Send request */
        packet_buf_flush(&req_buf);
-       write_or_die(fd_out, req_buf.buf, req_buf.len);
+       if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
+               die_errno("unable to write request to remote");
 
        strbuf_release(&req_buf);
        return ret;
diff --git a/pkt-line.c b/pkt-line.c
index d4b71d3e82..093b2f3976 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -88,13 +88,15 @@ static void packet_trace(const char *buf, unsigned int len, 
int write)
 void packet_flush(int fd)
 {
        packet_trace("0000", 4, 1);
-       write_or_die(fd, "0000", 4);
+       if (write_in_full(fd, "0000", 4) < 0)
+               die_errno("unable to write flush packet");
 }
 
 void packet_delim(int fd)
 {
        packet_trace("0001", 4, 1);
-       write_or_die(fd, "0001", 4);
+       if (write_in_full(fd, "0001", 4) < 0)
+               die_errno("unable to write delim packet");
 }
 
 int packet_flush_gently(int fd)
-- 
2.21.0.675.g01c085a870