On 3/3/21 2:53 PM, Junio C Hamano wrote:
"Johannes Schindelin via GitGitGadget" <gitgitgadget@xxxxxxxxx>
writes:
@@ -313,6 +316,8 @@ static int get_packet_data(int fd, char **src_buf,
if (options & PACKET_READ_GENTLE_ON_EOF)
return -1;
+ if (options & PACKET_READ_NEVER_DIE)
+ return error(_("the remote end hung up unexpectedly"));
die(_("the remote end hung up unexpectedly"));
}
This hunk treats READ_NEVER_DIE as a less quiet version of
GENTRL_ON_EOF, i.e. the new flag allows to continue even after the
"hung up unexpectedly" condition that usually causes the process to
die..
@@ -355,12 +363,19 @@ enum packet_read_status packet_read_with_status(i
...
- if ((unsigned)len >= size)
+ if ((unsigned)len >= size) {
+ if (options & PACKET_READ_NEVER_DIE)
+ return error(_("protocol error: bad line length %d"),
+ len);
die(_("protocol error: bad line length %d"), len);
+ }
if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
*pktlen = -1;
In the post-context of this hunk, there is this code:
if ((options & PACKET_READ_DIE_ON_ERR_PACKET) &&
starts_with(buffer, "ERR "))
die(_("remote error: %s"), buffer + 4);
*pktlen = len;
return PACKET_READ_NORMAL;
But here, there is no way to override the DIE_ON_ERR with
READ_NEVER_DIE.
The asymmetry is somewhat annoying (i.e. if "if you do not want to
die upon ERR, don't pass DIE_ON_ERR" could be a valid suggestion to
the callers, then "if you do not want to die upon an unexpected
hung-up, pass GENTLE_ON_EOF" would equally be valid suggestion),
but I'll let it pass.
I agree that there is something odd about all of these flags,
but I don't have the context on all the various caller combinations
to make a better suggestion at this time. And I certainly don't
want to stir up a bigger mess than I already have. :-)
We did document in the .h that READ_NEVER_DIE excludes ERR packets
when READ_DIE_ON_ERR is set, so I think we're safe from unexpected
surprises.
diff --git a/pkt-line.h b/pkt-line.h
index a7149429ac35..2e472efaf2c5 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -75,10 +75,14 @@ int write_packetized_from_buf_no_flush(const char *src_in, size_t len, int fd_ou
*
* If options contains PACKET_READ_DIE_ON_ERR_PACKET, it dies when it sees an
* ERR packet.
+ *
+ * With `PACKET_READ_NEVER_DIE`, no errors are allowed to trigger die() (except
+ * an ERR packet, when `PACKET_READ_DIE_ON_ERR_PACKET` is in effect).
*/
#define PACKET_READ_GENTLE_ON_EOF (1u<<0)
#define PACKET_READ_CHOMP_NEWLINE (1u<<1)
#define PACKET_READ_DIE_ON_ERR_PACKET (1u<<2)
+#define PACKET_READ_NEVER_DIE (1u<<3)
int packet_read(int fd, char **src_buffer, size_t *src_len, char
*buffer, unsigned size, int options);
