git/send-pack.c
Junio C Hamano 75e5c0dc55 push: introduce REJECT_FETCH_FIRST and REJECT_NEEDS_FORCE
When we push to update an existing ref, if:

 * the object at the tip of the remote is not a commit; or
 * the object we are pushing is not a commit,

it won't be correct to suggest to fetch, integrate and push again,
as the old and new objects will not "merge".  We should explain that
the push must be forced when there is a non-committish object is
involved in such a case.

If we do not have the current object at the tip of the remote, we do
not even know that object, when fetched, is something that can be
merged.  In such a case, suggesting to pull first just like
non-fast-forward case may not be technically correct, but in
practice, most such failures are seen when you try to push your work
to a branch without knowing that somebody else already pushed to
update the same branch since you forked, so "pull first" would work
as a suggestion most of the time.  And if the object at the tip is
not a commit, "pull first" will fail, without making any permanent
damage.  As a side effect, it also makes the error message the user
will get during the next "push" attempt easier to understand, now
the user is aware that a non-commit object is involved.

In these cases, the current code already rejects such a push on the
client end, but we used the same error and advice messages as the
ones used when rejecting a non-fast-forward push, i.e. pull from
there and integrate before pushing again.

Introduce new rejection reasons and reword the messages
appropriately.

[jc: with help by Peff on message details]

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-01-24 14:37:23 -08:00

348 lines
7.8 KiB
C

#include "builtin.h"
#include "commit.h"
#include "refs.h"
#include "pkt-line.h"
#include "sideband.h"
#include "run-command.h"
#include "remote.h"
#include "send-pack.h"
#include "quote.h"
#include "transport.h"
#include "version.h"
static int feed_object(const unsigned char *sha1, int fd, int negative)
{
char buf[42];
if (negative && !has_sha1_file(sha1))
return 1;
memcpy(buf + negative, sha1_to_hex(sha1), 40);
if (negative)
buf[0] = '^';
buf[40 + negative] = '\n';
return write_or_whine(fd, buf, 41 + negative, "send-pack: send refs");
}
/*
* Make a pack stream and spit it out into file descriptor fd
*/
static int pack_objects(int fd, struct ref *refs, struct extra_have_objects *extra, struct send_pack_args *args)
{
/*
* The child becomes pack-objects --revs; we feed
* the revision parameters to it via its stdin and
* let its stdout go back to the other end.
*/
const char *argv[] = {
"pack-objects",
"--all-progress-implied",
"--revs",
"--stdout",
NULL,
NULL,
NULL,
NULL,
NULL,
};
struct child_process po;
int i;
i = 4;
if (args->use_thin_pack)
argv[i++] = "--thin";
if (args->use_ofs_delta)
argv[i++] = "--delta-base-offset";
if (args->quiet || !args->progress)
argv[i++] = "-q";
if (args->progress)
argv[i++] = "--progress";
memset(&po, 0, sizeof(po));
po.argv = argv;
po.in = -1;
po.out = args->stateless_rpc ? -1 : fd;
po.git_cmd = 1;
if (start_command(&po))
die_errno("git pack-objects failed");
/*
* We feed the pack-objects we just spawned with revision
* parameters by writing to the pipe.
*/
for (i = 0; i < extra->nr; i++)
if (!feed_object(extra->array[i], po.in, 1))
break;
while (refs) {
if (!is_null_sha1(refs->old_sha1) &&
!feed_object(refs->old_sha1, po.in, 1))
break;
if (!is_null_sha1(refs->new_sha1) &&
!feed_object(refs->new_sha1, po.in, 0))
break;
refs = refs->next;
}
close(po.in);
if (args->stateless_rpc) {
char *buf = xmalloc(LARGE_PACKET_MAX);
while (1) {
ssize_t n = xread(po.out, buf, LARGE_PACKET_MAX);
if (n <= 0)
break;
send_sideband(fd, -1, buf, n, LARGE_PACKET_MAX);
}
free(buf);
close(po.out);
po.out = -1;
}
if (finish_command(&po))
return -1;
return 0;
}
static int receive_status(int in, struct ref *refs)
{
struct ref *hint;
char line[1000];
int ret = 0;
int len = packet_read_line(in, line, sizeof(line));
if (len < 10 || memcmp(line, "unpack ", 7))
return error("did not receive remote status");
if (memcmp(line, "unpack ok\n", 10)) {
char *p = line + strlen(line) - 1;
if (*p == '\n')
*p = '\0';
error("unpack failed: %s", line + 7);
ret = -1;
}
hint = NULL;
while (1) {
char *refname;
char *msg;
len = packet_read_line(in, line, sizeof(line));
if (!len)
break;
if (len < 3 ||
(memcmp(line, "ok ", 3) && memcmp(line, "ng ", 3))) {
fprintf(stderr, "protocol error: %s\n", line);
ret = -1;
break;
}
line[strlen(line)-1] = '\0';
refname = line + 3;
msg = strchr(refname, ' ');
if (msg)
*msg++ = '\0';
/* first try searching at our hint, falling back to all refs */
if (hint)
hint = find_ref_by_name(hint, refname);
if (!hint)
hint = find_ref_by_name(refs, refname);
if (!hint) {
warning("remote reported status on unknown ref: %s",
refname);
continue;
}
if (hint->status != REF_STATUS_EXPECTING_REPORT) {
warning("remote reported status on unexpected ref: %s",
refname);
continue;
}
if (line[0] == 'o' && line[1] == 'k')
hint->status = REF_STATUS_OK;
else {
hint->status = REF_STATUS_REMOTE_REJECT;
ret = -1;
}
if (msg)
hint->remote_status = xstrdup(msg);
/* start our next search from the next ref */
hint = hint->next;
}
return ret;
}
static int sideband_demux(int in, int out, void *data)
{
int *fd = data, ret;
#ifdef NO_PTHREADS
close(fd[1]);
#endif
ret = recv_sideband("send-pack", fd[0], out);
close(out);
return ret;
}
int send_pack(struct send_pack_args *args,
int fd[], struct child_process *conn,
struct ref *remote_refs,
struct extra_have_objects *extra_have)
{
int in = fd[0];
int out = fd[1];
struct strbuf req_buf = STRBUF_INIT;
struct ref *ref;
int new_refs;
int allow_deleting_refs = 0;
int status_report = 0;
int use_sideband = 0;
int quiet_supported = 0;
int agent_supported = 0;
unsigned cmds_sent = 0;
int ret;
struct async demux;
/* Does the other end support the reporting? */
if (server_supports("report-status"))
status_report = 1;
if (server_supports("delete-refs"))
allow_deleting_refs = 1;
if (server_supports("ofs-delta"))
args->use_ofs_delta = 1;
if (server_supports("side-band-64k"))
use_sideband = 1;
if (server_supports("quiet"))
quiet_supported = 1;
if (server_supports("agent"))
agent_supported = 1;
if (!remote_refs) {
fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
"Perhaps you should specify a branch such as 'master'.\n");
return 0;
}
/*
* Finally, tell the other end!
*/
new_refs = 0;
for (ref = remote_refs; ref; ref = ref->next) {
if (!ref->peer_ref && !args->send_mirror)
continue;
/* Check for statuses set by set_ref_status_for_push() */
switch (ref->status) {
case REF_STATUS_REJECT_NONFASTFORWARD:
case REF_STATUS_REJECT_ALREADY_EXISTS:
case REF_STATUS_REJECT_FETCH_FIRST:
case REF_STATUS_REJECT_NEEDS_FORCE:
case REF_STATUS_UPTODATE:
continue;
default:
; /* do nothing */
}
if (ref->deletion && !allow_deleting_refs) {
ref->status = REF_STATUS_REJECT_NODELETE;
continue;
}
if (!ref->deletion)
new_refs++;
if (args->dry_run) {
ref->status = REF_STATUS_OK;
} else {
char *old_hex = sha1_to_hex(ref->old_sha1);
char *new_hex = sha1_to_hex(ref->new_sha1);
int quiet = quiet_supported && (args->quiet || !args->progress);
if (!cmds_sent && (status_report || use_sideband ||
quiet || agent_supported)) {
packet_buf_write(&req_buf,
"%s %s %s%c%s%s%s%s%s",
old_hex, new_hex, ref->name, 0,
status_report ? " report-status" : "",
use_sideband ? " side-band-64k" : "",
quiet ? " quiet" : "",
agent_supported ? " agent=" : "",
agent_supported ? git_user_agent_sanitized() : ""
);
}
else
packet_buf_write(&req_buf, "%s %s %s",
old_hex, new_hex, ref->name);
ref->status = status_report ?
REF_STATUS_EXPECTING_REPORT :
REF_STATUS_OK;
cmds_sent++;
}
}
if (args->stateless_rpc) {
if (!args->dry_run && cmds_sent) {
packet_buf_flush(&req_buf);
send_sideband(out, -1, req_buf.buf, req_buf.len, LARGE_PACKET_MAX);
}
} else {
safe_write(out, req_buf.buf, req_buf.len);
packet_flush(out);
}
strbuf_release(&req_buf);
if (use_sideband && cmds_sent) {
memset(&demux, 0, sizeof(demux));
demux.proc = sideband_demux;
demux.data = fd;
demux.out = -1;
if (start_async(&demux))
die("send-pack: unable to fork off sideband demultiplexer");
in = demux.out;
}
if (new_refs && cmds_sent) {
if (pack_objects(out, remote_refs, extra_have, args) < 0) {
for (ref = remote_refs; ref; ref = ref->next)
ref->status = REF_STATUS_NONE;
if (args->stateless_rpc)
close(out);
if (git_connection_is_socket(conn))
shutdown(fd[0], SHUT_WR);
if (use_sideband)
finish_async(&demux);
return -1;
}
}
if (args->stateless_rpc && cmds_sent)
packet_flush(out);
if (status_report && cmds_sent)
ret = receive_status(in, remote_refs);
else
ret = 0;
if (args->stateless_rpc)
packet_flush(out);
if (use_sideband && cmds_sent) {
if (finish_async(&demux)) {
error("error in sideband demultiplexer");
ret = -1;
}
close(demux.out);
}
if (ret < 0)
return ret;
if (args->porcelain)
return 0;
for (ref = remote_refs; ref; ref = ref->next) {
switch (ref->status) {
case REF_STATUS_NONE:
case REF_STATUS_UPTODATE:
case REF_STATUS_OK:
break;
default:
return -1;
}
}
return 0;
}