pkt-line: do not report packet write errors twice

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 an 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 common lower level function
that doesn't print the error message, but instead returns it on a buffer
for the caller to die() or error() as appropriate.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/pkt-line.c b/pkt-line.c
index 0194137528c3ce909ab76f55200e2ed31ce742f7..98304ce374de8b0c5a4979700230e5f89da30a48 100644 (file)
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -194,13 +194,16 @@ 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,
+                          struct strbuf *err)
 {
        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) {
+               strbuf_addstr(err, _("packet write failed - data exceeds max packet size"));
+               return -1;
+       }
 
        packet_trace(buf, size, 1);
        packet_size = size + 4;
@@ -215,15 +218,29 @@ 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) {
+               strbuf_addf(err, _("packet write failed: %s"), strerror(errno));
+               return -1;
+       }
+       return 0;
+}
+
+static int packet_write_gently(const int fd_out, const char *buf, size_t size)
+{
+       struct strbuf err = STRBUF_INIT;
+       if (do_packet_write(fd_out, buf, size, &err)) {
+               error("%s", err.buf);
+               strbuf_release(&err);
+               return -1;
+       }
        return 0;
 }
 
 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"));
+       struct strbuf err = STRBUF_INIT;
+       if (do_packet_write(fd_out, buf, size, &err))
+               die("%s", err.buf);
 }
 
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)