git/builtin-fetch.c
Johannes Schindelin 8ee5d73137 Fix fetch/pull when run without --update-head-ok
Some confusing tutorials suggested that it would be a good idea to fetch
into the current branch with something like this:

	git fetch origin master:master

(or even worse: the same command line with "pull" instead of "fetch").
While it might make sense to store what you want to pull, it typically is
plain wrong when the current branch is "master".  This should only be
allowed when (an incorrect) "git pull origin master:master" tries to work
around by giving --update-head-ok to underlying "git fetch", and otherwise
we should refuse it, but somewhere along the lines we lost that behavior.

The check for the current branch is now _only_ performed in non-bare
repositories, which is an improvement from the original behaviour.

Some newer tests were depending on the broken behaviour of "git fetch"
this patch fixes, and have been adjusted.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Acked-by: Shawn O. Pearce <spearce@spearce.org>
Acked-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-10-13 10:46:03 -07:00

684 lines
18 KiB
C

/*
* "git fetch"
*/
#include "cache.h"
#include "refs.h"
#include "commit.h"
#include "builtin.h"
#include "string-list.h"
#include "remote.h"
#include "transport.h"
#include "run-command.h"
#include "parse-options.h"
static const char * const builtin_fetch_usage[] = {
"git fetch [options] [<repository> <refspec>...]",
NULL
};
enum {
TAGS_UNSET = 0,
TAGS_DEFAULT = 1,
TAGS_SET = 2
};
static int append, force, keep, update_head_ok, verbose, quiet;
static int tags = TAGS_DEFAULT;
static const char *depth;
static const char *upload_pack;
static struct strbuf default_rla = STRBUF_INIT;
static struct transport *transport;
static struct option builtin_fetch_options[] = {
OPT__QUIET(&quiet),
OPT__VERBOSE(&verbose),
OPT_BOOLEAN('a', "append", &append,
"append to .git/FETCH_HEAD instead of overwriting"),
OPT_STRING(0, "upload-pack", &upload_pack, "PATH",
"path to upload pack on remote end"),
OPT_BOOLEAN('f', "force", &force,
"force overwrite of local branch"),
OPT_SET_INT('t', "tags", &tags,
"fetch all tags and associated objects", TAGS_SET),
OPT_SET_INT('n', NULL, &tags,
"do not fetch all tags (--no-tags)", TAGS_UNSET),
OPT_BOOLEAN('k', "keep", &keep, "keep downloaded pack"),
OPT_BOOLEAN('u', "update-head-ok", &update_head_ok,
"allow updating of HEAD ref"),
OPT_STRING(0, "depth", &depth, "DEPTH",
"deepen history of shallow clone"),
OPT_END()
};
static void unlock_pack(void)
{
if (transport)
transport_unlock_pack(transport);
}
static void unlock_pack_on_signal(int signo)
{
unlock_pack();
signal(SIGINT, SIG_DFL);
raise(signo);
}
static void add_merge_config(struct ref **head,
const struct ref *remote_refs,
struct branch *branch,
struct ref ***tail)
{
int i;
for (i = 0; i < branch->merge_nr; i++) {
struct ref *rm, **old_tail = *tail;
struct refspec refspec;
for (rm = *head; rm; rm = rm->next) {
if (branch_merge_matches(branch, i, rm->name)) {
rm->merge = 1;
break;
}
}
if (rm)
continue;
/*
* Not fetched to a tracking branch? We need to fetch
* it anyway to allow this branch's "branch.$name.merge"
* to be honored by 'git pull', but we do not have to
* fail if branch.$name.merge is misconfigured to point
* at a nonexisting branch. If we were indeed called by
* 'git pull', it will notice the misconfiguration because
* there is no entry in the resulting FETCH_HEAD marked
* for merging.
*/
refspec.src = branch->merge[i]->src;
refspec.dst = NULL;
refspec.pattern = 0;
refspec.force = 0;
get_fetch_map(remote_refs, &refspec, tail, 1);
for (rm = *old_tail; rm; rm = rm->next)
rm->merge = 1;
}
}
static void find_non_local_tags(struct transport *transport,
struct ref **head,
struct ref ***tail);
static struct ref *get_ref_map(struct transport *transport,
struct refspec *refs, int ref_count, int tags,
int *autotags)
{
int i;
struct ref *rm;
struct ref *ref_map = NULL;
struct ref **tail = &ref_map;
const struct ref *remote_refs = transport_get_remote_refs(transport);
if (ref_count || tags == TAGS_SET) {
for (i = 0; i < ref_count; i++) {
get_fetch_map(remote_refs, &refs[i], &tail, 0);
if (refs[i].dst && refs[i].dst[0])
*autotags = 1;
}
/* Merge everything on the command line, but not --tags */
for (rm = ref_map; rm; rm = rm->next)
rm->merge = 1;
if (tags == TAGS_SET)
get_fetch_map(remote_refs, tag_refspec, &tail, 0);
} else {
/* Use the defaults */
struct remote *remote = transport->remote;
struct branch *branch = branch_get(NULL);
int has_merge = branch_has_merge_config(branch);
if (remote && (remote->fetch_refspec_nr || has_merge)) {
for (i = 0; i < remote->fetch_refspec_nr; i++) {
get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
if (remote->fetch[i].dst &&
remote->fetch[i].dst[0])
*autotags = 1;
if (!i && !has_merge && ref_map &&
!remote->fetch[0].pattern)
ref_map->merge = 1;
}
/*
* if the remote we're fetching from is the same
* as given in branch.<name>.remote, we add the
* ref given in branch.<name>.merge, too.
*/
if (has_merge &&
!strcmp(branch->remote_name, remote->name))
add_merge_config(&ref_map, remote_refs, branch, &tail);
} else {
ref_map = get_remote_ref(remote_refs, "HEAD");
if (!ref_map)
die("Couldn't find remote ref HEAD");
ref_map->merge = 1;
tail = &ref_map->next;
}
}
if (tags == TAGS_DEFAULT && *autotags)
find_non_local_tags(transport, &ref_map, &tail);
ref_remove_duplicates(ref_map);
return ref_map;
}
static int s_update_ref(const char *action,
struct ref *ref,
int check_old)
{
char msg[1024];
char *rla = getenv("GIT_REFLOG_ACTION");
static struct ref_lock *lock;
if (!rla)
rla = default_rla.buf;
snprintf(msg, sizeof(msg), "%s: %s", rla, action);
lock = lock_any_ref_for_update(ref->name,
check_old ? ref->old_sha1 : NULL, 0);
if (!lock)
return 2;
if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
return 2;
return 0;
}
#define SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)
#define REFCOL_WIDTH 10
static int update_local_ref(struct ref *ref,
const char *remote,
int verbose,
char *display)
{
struct commit *current = NULL, *updated;
enum object_type type;
struct branch *current_branch = branch_get(NULL);
const char *pretty_ref = ref->name + (
!prefixcmp(ref->name, "refs/heads/") ? 11 :
!prefixcmp(ref->name, "refs/tags/") ? 10 :
!prefixcmp(ref->name, "refs/remotes/") ? 13 :
0);
*display = 0;
type = sha1_object_info(ref->new_sha1, NULL);
if (type < 0)
die("object %s not found", sha1_to_hex(ref->new_sha1));
if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
if (verbose)
sprintf(display, "= %-*s %-*s -> %s", SUMMARY_WIDTH,
"[up to date]", REFCOL_WIDTH, remote,
pretty_ref);
return 0;
}
if (current_branch &&
!strcmp(ref->name, current_branch->name) &&
!(update_head_ok || is_bare_repository()) &&
!is_null_sha1(ref->old_sha1)) {
/*
* If this is the head, and it's not okay to update
* the head, and the old value of the head isn't empty...
*/
sprintf(display, "! %-*s %-*s -> %s (can't fetch in current branch)",
SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
pretty_ref);
return 1;
}
if (!is_null_sha1(ref->old_sha1) &&
!prefixcmp(ref->name, "refs/tags/")) {
int r;
r = s_update_ref("updating tag", ref, 0);
sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : '-',
SUMMARY_WIDTH, "[tag update]", REFCOL_WIDTH, remote,
pretty_ref, r ? " (unable to update local ref)" : "");
return r;
}
current = lookup_commit_reference_gently(ref->old_sha1, 1);
updated = lookup_commit_reference_gently(ref->new_sha1, 1);
if (!current || !updated) {
const char *msg;
const char *what;
int r;
if (!strncmp(ref->name, "refs/tags/", 10)) {
msg = "storing tag";
what = "[new tag]";
}
else {
msg = "storing head";
what = "[new branch]";
}
r = s_update_ref(msg, ref, 0);
sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : '*',
SUMMARY_WIDTH, what, REFCOL_WIDTH, remote, pretty_ref,
r ? " (unable to update local ref)" : "");
return r;
}
if (in_merge_bases(current, &updated, 1)) {
char quickref[83];
int r;
strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
strcat(quickref, "..");
strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
r = s_update_ref("fast forward", ref, 1);
sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : ' ',
SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote,
pretty_ref, r ? " (unable to update local ref)" : "");
return r;
} else if (force || ref->force) {
char quickref[84];
int r;
strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
strcat(quickref, "...");
strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
r = s_update_ref("forced-update", ref, 1);
sprintf(display, "%c %-*s %-*s -> %s (%s)", r ? '!' : '+',
SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote,
pretty_ref,
r ? "unable to update local ref" : "forced update");
return r;
} else {
sprintf(display, "! %-*s %-*s -> %s (non fast forward)",
SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
pretty_ref);
return 1;
}
}
static int store_updated_refs(const char *url, const char *remote_name,
struct ref *ref_map)
{
FILE *fp;
struct commit *commit;
int url_len, i, note_len, shown_url = 0, rc = 0;
char note[1024];
const char *what, *kind;
struct ref *rm;
char *filename = git_path("FETCH_HEAD");
fp = fopen(filename, "a");
if (!fp)
return error("cannot open %s: %s\n", filename, strerror(errno));
for (rm = ref_map; rm; rm = rm->next) {
struct ref *ref = NULL;
if (rm->peer_ref) {
ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
strcpy(ref->name, rm->peer_ref->name);
hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
hashcpy(ref->new_sha1, rm->old_sha1);
ref->force = rm->peer_ref->force;
}
commit = lookup_commit_reference_gently(rm->old_sha1, 1);
if (!commit)
rm->merge = 0;
if (!strcmp(rm->name, "HEAD")) {
kind = "";
what = "";
}
else if (!prefixcmp(rm->name, "refs/heads/")) {
kind = "branch";
what = rm->name + 11;
}
else if (!prefixcmp(rm->name, "refs/tags/")) {
kind = "tag";
what = rm->name + 10;
}
else if (!prefixcmp(rm->name, "refs/remotes/")) {
kind = "remote branch";
what = rm->name + 13;
}
else {
kind = "";
what = rm->name;
}
url_len = strlen(url);
for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
;
url_len = i + 1;
if (4 < i && !strncmp(".git", url + i - 3, 4))
url_len = i - 3;
note_len = 0;
if (*what) {
if (*kind)
note_len += sprintf(note + note_len, "%s ",
kind);
note_len += sprintf(note + note_len, "'%s' of ", what);
}
note_len += sprintf(note + note_len, "%.*s", url_len, url);
fprintf(fp, "%s\t%s\t%s\n",
sha1_to_hex(commit ? commit->object.sha1 :
rm->old_sha1),
rm->merge ? "" : "not-for-merge",
note);
if (ref)
rc |= update_local_ref(ref, what, verbose, note);
else
sprintf(note, "* %-*s %-*s -> FETCH_HEAD",
SUMMARY_WIDTH, *kind ? kind : "branch",
REFCOL_WIDTH, *what ? what : "HEAD");
if (*note) {
if (!shown_url) {
fprintf(stderr, "From %.*s\n",
url_len, url);
shown_url = 1;
}
fprintf(stderr, " %s\n", note);
}
}
fclose(fp);
if (rc & 2)
error("some local refs could not be updated; try running\n"
" 'git remote prune %s' to remove any old, conflicting "
"branches", remote_name);
return rc;
}
/*
* We would want to bypass the object transfer altogether if
* everything we are going to fetch already exists and connected
* locally.
*
* The refs we are going to fetch are in to_fetch (nr_heads in
* total). If running
*
* $ git rev-list --objects to_fetch[0] to_fetch[1] ... --not --all
*
* does not error out, that means everything reachable from the
* refs we are going to fetch exists and is connected to some of
* our existing refs.
*/
static int quickfetch(struct ref *ref_map)
{
struct child_process revlist;
struct ref *ref;
char **argv;
int i, err;
/*
* If we are deepening a shallow clone we already have these
* objects reachable. Running rev-list here will return with
* a good (0) exit status and we'll bypass the fetch that we
* really need to perform. Claiming failure now will ensure
* we perform the network exchange to deepen our history.
*/
if (depth)
return -1;
for (i = 0, ref = ref_map; ref; ref = ref->next)
i++;
if (!i)
return 0;
argv = xmalloc(sizeof(*argv) * (i + 6));
i = 0;
argv[i++] = xstrdup("rev-list");
argv[i++] = xstrdup("--quiet");
argv[i++] = xstrdup("--objects");
for (ref = ref_map; ref; ref = ref->next)
argv[i++] = xstrdup(sha1_to_hex(ref->old_sha1));
argv[i++] = xstrdup("--not");
argv[i++] = xstrdup("--all");
argv[i++] = NULL;
memset(&revlist, 0, sizeof(revlist));
revlist.argv = (const char**)argv;
revlist.git_cmd = 1;
revlist.no_stdin = 1;
revlist.no_stdout = 1;
revlist.no_stderr = 1;
err = run_command(&revlist);
for (i = 0; argv[i]; i++)
free(argv[i]);
free(argv);
return err;
}
static int fetch_refs(struct transport *transport, struct ref *ref_map)
{
int ret = quickfetch(ref_map);
if (ret)
ret = transport_fetch_refs(transport, ref_map);
if (!ret)
ret |= store_updated_refs(transport->url,
transport->remote->name,
ref_map);
transport_unlock_pack(transport);
return ret;
}
static int add_existing(const char *refname, const unsigned char *sha1,
int flag, void *cbdata)
{
struct string_list *list = (struct string_list *)cbdata;
string_list_insert(refname, list);
return 0;
}
static int will_fetch(struct ref **head, const unsigned char *sha1)
{
struct ref *rm = *head;
while (rm) {
if (!hashcmp(rm->old_sha1, sha1))
return 1;
rm = rm->next;
}
return 0;
}
static void find_non_local_tags(struct transport *transport,
struct ref **head,
struct ref ***tail)
{
struct string_list existing_refs = { NULL, 0, 0, 0 };
struct string_list new_refs = { NULL, 0, 0, 1 };
char *ref_name;
int ref_name_len;
const unsigned char *ref_sha1;
const struct ref *tag_ref;
struct ref *rm = NULL;
const struct ref *ref;
for_each_ref(add_existing, &existing_refs);
for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
if (prefixcmp(ref->name, "refs/tags"))
continue;
ref_name = xstrdup(ref->name);
ref_name_len = strlen(ref_name);
ref_sha1 = ref->old_sha1;
if (!strcmp(ref_name + ref_name_len - 3, "^{}")) {
ref_name[ref_name_len - 3] = 0;
tag_ref = transport_get_remote_refs(transport);
while (tag_ref) {
if (!strcmp(tag_ref->name, ref_name)) {
ref_sha1 = tag_ref->old_sha1;
break;
}
tag_ref = tag_ref->next;
}
}
if (!string_list_has_string(&existing_refs, ref_name) &&
!string_list_has_string(&new_refs, ref_name) &&
(has_sha1_file(ref->old_sha1) ||
will_fetch(head, ref->old_sha1))) {
string_list_insert(ref_name, &new_refs);
rm = alloc_ref_from_str(ref_name);
rm->peer_ref = alloc_ref_from_str(ref_name);
hashcpy(rm->old_sha1, ref_sha1);
**tail = rm;
*tail = &rm->next;
}
free(ref_name);
}
string_list_clear(&existing_refs, 0);
string_list_clear(&new_refs, 0);
}
static void check_not_current_branch(struct ref *ref_map)
{
struct branch *current_branch = branch_get(NULL);
if (is_bare_repository() || !current_branch)
return;
for (; ref_map; ref_map = ref_map->next)
if (ref_map->peer_ref && !strcmp(current_branch->refname,
ref_map->peer_ref->name))
die("Refusing to fetch into current branch");
}
static int do_fetch(struct transport *transport,
struct refspec *refs, int ref_count)
{
struct ref *ref_map;
struct ref *rm;
int autotags = (transport->remote->fetch_tags == 1);
if (transport->remote->fetch_tags == 2 && tags != TAGS_UNSET)
tags = TAGS_SET;
if (transport->remote->fetch_tags == -1)
tags = TAGS_UNSET;
if (!transport->get_refs_list || !transport->fetch)
die("Don't know how to fetch from %s", transport->url);
/* if not appending, truncate FETCH_HEAD */
if (!append) {
char *filename = git_path("FETCH_HEAD");
FILE *fp = fopen(filename, "w");
if (!fp)
return error("cannot open %s: %s\n", filename, strerror(errno));
fclose(fp);
}
ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
if (!update_head_ok)
check_not_current_branch(ref_map);
for (rm = ref_map; rm; rm = rm->next) {
if (rm->peer_ref)
read_ref(rm->peer_ref->name, rm->peer_ref->old_sha1);
}
if (tags == TAGS_DEFAULT && autotags)
transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
if (fetch_refs(transport, ref_map)) {
free_refs(ref_map);
return 1;
}
free_refs(ref_map);
/* if neither --no-tags nor --tags was specified, do automated tag
* following ... */
if (tags == TAGS_DEFAULT && autotags) {
struct ref **tail = &ref_map;
ref_map = NULL;
find_non_local_tags(transport, &ref_map, &tail);
if (ref_map) {
transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
transport_set_option(transport, TRANS_OPT_DEPTH, "0");
fetch_refs(transport, ref_map);
}
free_refs(ref_map);
}
return 0;
}
static void set_option(const char *name, const char *value)
{
int r = transport_set_option(transport, name, value);
if (r < 0)
die("Option \"%s\" value \"%s\" is not valid for %s\n",
name, value, transport->url);
if (r > 0)
warning("Option \"%s\" is ignored for %s\n",
name, transport->url);
}
int cmd_fetch(int argc, const char **argv, const char *prefix)
{
struct remote *remote;
int i;
static const char **refs = NULL;
int ref_nr = 0;
int exit_code;
/* Record the command line for the reflog */
strbuf_addstr(&default_rla, "fetch");
for (i = 1; i < argc; i++)
strbuf_addf(&default_rla, " %s", argv[i]);
argc = parse_options(argc, argv,
builtin_fetch_options, builtin_fetch_usage, 0);
if (argc == 0)
remote = remote_get(NULL);
else
remote = remote_get(argv[0]);
transport = transport_get(remote, remote->url[0]);
if (verbose >= 2)
transport->verbose = 1;
if (quiet)
transport->verbose = -1;
if (upload_pack)
set_option(TRANS_OPT_UPLOADPACK, upload_pack);
if (keep)
set_option(TRANS_OPT_KEEP, "yes");
if (depth)
set_option(TRANS_OPT_DEPTH, depth);
if (!transport->url)
die("Where do you want to fetch from today?");
if (argc > 1) {
int j = 0;
refs = xcalloc(argc + 1, sizeof(const char *));
for (i = 1; i < argc; i++) {
if (!strcmp(argv[i], "tag")) {
char *ref;
i++;
if (i >= argc)
die("You need to specify a tag name.");
ref = xmalloc(strlen(argv[i]) * 2 + 22);
strcpy(ref, "refs/tags/");
strcat(ref, argv[i]);
strcat(ref, ":refs/tags/");
strcat(ref, argv[i]);
refs[j++] = ref;
} else
refs[j++] = argv[i];
}
refs[j] = NULL;
ref_nr = j;
}
signal(SIGINT, unlock_pack_on_signal);
atexit(unlock_pack);
exit_code = do_fetch(transport,
parse_fetch_refspec(ref_nr, refs), ref_nr);
transport_disconnect(transport);
transport = NULL;
return exit_code;
}