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/*
* Builtin "git pull"
*
* Based on git-pull.sh by Junio C Hamano
*
* Fetch one or more remote refs and merge it/them into the current HEAD.
*/
#include "cache.h"
#include "builtin.h"
#include "parse-options.h"
#include "exec_cmd.h"
#include "run-command.h"
#include "sha1-array.h"
#include "remote.h"
#include "dir.h"
#include "refs.h"
static const char * const pull_usage[] = {
N_("git pull [options] [<repository> [<refspec>...]]"),
NULL
};
/* Shared options */
static int opt_verbosity;
static char *opt_progress;
/* Options passed to git-merge */
static char *opt_diffstat;
static char *opt_log;
static char *opt_squash;
static char *opt_commit;
static char *opt_edit;
static char *opt_ff;
static char *opt_verify_signatures;
static struct argv_array opt_strategies = ARGV_ARRAY_INIT;
static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT;
static char *opt_gpg_sign;
/* Options passed to git-fetch */
static char *opt_all;
static char *opt_append;
static char *opt_upload_pack;
static int opt_force;
static char *opt_tags;
static char *opt_prune;
static char *opt_recurse_submodules;
static int opt_dry_run;
static char *opt_keep;
static char *opt_depth;
static char *opt_unshallow;
static char *opt_update_shallow;
static char *opt_refmap;
static struct option pull_options[] = {
/* Shared options */
OPT__VERBOSITY(&opt_verbosity),
OPT_PASSTHRU(0, "progress", &opt_progress, NULL,
N_("force progress reporting"),
PARSE_OPT_NOARG),
/* Options passed to git-merge */
OPT_GROUP(N_("Options related to merging")),
OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
N_("do not show a diffstat at the end of the merge"),
PARSE_OPT_NOARG | PARSE_OPT_NONEG),
OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL,
N_("show a diffstat at the end of the merge"),
PARSE_OPT_NOARG),
OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL,
N_("(synonym to --stat)"),
PARSE_OPT_NOARG | PARSE_OPT_HIDDEN),
OPT_PASSTHRU(0, "log", &opt_log, N_("n"),
N_("add (at most <n>) entries from shortlog to merge commit message"),
PARSE_OPT_OPTARG),
OPT_PASSTHRU(0, "squash", &opt_squash, NULL,
N_("create a single commit instead of doing a merge"),
PARSE_OPT_NOARG),
OPT_PASSTHRU(0, "commit", &opt_commit, NULL,
N_("perform a commit if the merge succeeds (default)"),
PARSE_OPT_NOARG),
OPT_PASSTHRU(0, "edit", &opt_edit, NULL,
N_("edit message before committing"),
PARSE_OPT_NOARG),
OPT_PASSTHRU(0, "ff", &opt_ff, NULL,
N_("allow fast-forward"),
PARSE_OPT_NOARG),
OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL,
N_("abort if fast-forward is not possible"),
PARSE_OPT_NOARG | PARSE_OPT_NONEG),
OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
N_("verify that the named commit has a valid GPG signature"),
PARSE_OPT_NOARG),
OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
N_("merge strategy to use"),
0),
OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts,
N_("option=value"),
N_("option for selected merge strategy"),
0),
OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
N_("GPG sign commit"),
PARSE_OPT_OPTARG),
/* Options passed to git-fetch */
OPT_GROUP(N_("Options related to fetching")),
OPT_PASSTHRU(0, "all", &opt_all, NULL,
N_("fetch from all remotes"),
PARSE_OPT_NOARG),
OPT_PASSTHRU('a', "append", &opt_append, NULL,
N_("append to .git/FETCH_HEAD instead of overwriting"),
PARSE_OPT_NOARG),
OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"),
N_("path to upload pack on remote end"),
0),
OPT__FORCE(&opt_force, N_("force overwrite of local branch")),
OPT_PASSTHRU('t', "tags", &opt_tags, NULL,
N_("fetch all tags and associated objects"),
PARSE_OPT_NOARG),
OPT_PASSTHRU('p', "prune", &opt_prune, NULL,
N_("prune remote-tracking branches no longer on remote"),
PARSE_OPT_NOARG),
OPT_PASSTHRU(0, "recurse-submodules", &opt_recurse_submodules,
N_("on-demand"),
N_("control recursive fetching of submodules"),
PARSE_OPT_OPTARG),
OPT_BOOL(0, "dry-run", &opt_dry_run,
N_("dry run")),
OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
N_("keep downloaded pack"),
PARSE_OPT_NOARG),
OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
N_("deepen history of shallow clone"),
0),
OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
N_("convert to a complete repository"),
PARSE_OPT_NONEG | PARSE_OPT_NOARG),
OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL,
N_("accept refs that update .git/shallow"),
PARSE_OPT_NOARG),
OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
N_("specify fetch refmap"),
PARSE_OPT_NONEG),
OPT_END()
};
/**
* Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
*/
static void argv_push_verbosity(struct argv_array *arr)
{
int verbosity;
for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
argv_array_push(arr, "-v");
for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
argv_array_push(arr, "-q");
}
/**
* Pushes "-f" switches into arr to match the opt_force level.
*/
static void argv_push_force(struct argv_array *arr)
{
int force = opt_force;
while (force-- > 0)
argv_array_push(arr, "-f");
}
/**
* If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
* pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
* "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
* error.
*/
static const char *config_get_ff(void)
{
const char *value;
if (git_config_get_value("pull.ff", &value))
return NULL;
switch (git_config_maybe_bool("pull.ff", value)) {
case 0:
return "--no-ff";
case 1:
return "--ff";
}
if (!strcmp(value, "only"))
return "--ff-only";
die(_("Invalid value for pull.ff: %s"), value);
}
/**
* Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
* into merge_heads.
*/
static void get_merge_heads(struct sha1_array *merge_heads)
{
const char *filename = git_path("FETCH_HEAD");
FILE *fp;
struct strbuf sb = STRBUF_INIT;
unsigned char sha1[GIT_SHA1_RAWSZ];
if (!(fp = fopen(filename, "r")))
die_errno(_("could not open '%s' for reading"), filename);
while (strbuf_getline(&sb, fp, '\n') != EOF) {
if (get_sha1_hex(sb.buf, sha1))
continue; /* invalid line: does not start with SHA1 */
if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t"))
continue; /* ref is not-for-merge */
sha1_array_append(merge_heads, sha1);
}
fclose(fp);
strbuf_release(&sb);
}
/**
* Used by die_no_merge_candidates() as a for_each_remote() callback to
* retrieve the name of the remote if the repository only has one remote.
*/
static int get_only_remote(struct remote *remote, void *cb_data)
{
const char **remote_name = cb_data;
if (*remote_name)
return -1;
*remote_name = remote->name;
return 0;
}
/**
* Dies with the appropriate reason for why there are no merge candidates:
*
* 1. We fetched from a specific remote, and a refspec was given, but it ended
* up not fetching anything. This is usually because the user provided a
* wildcard refspec which had no matches on the remote end.
*
* 2. We fetched from a non-default remote, but didn't specify a branch to
* merge. We can't use the configured one because it applies to the default
* remote, thus the user must specify the branches to merge.
*
* 3. We fetched from the branch's or repo's default remote, but:
*
* a. We are not on a branch, so there will never be a configured branch to
* merge with.
*
* b. We are on a branch, but there is no configured branch to merge with.
*
* 4. We fetched from the branch's or repo's default remote, but the configured
* branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
* part of the configured fetch refspec.)
*/
static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
{
struct branch *curr_branch = branch_get("HEAD");
const char *remote = curr_branch ? curr_branch->remote_name : NULL;
if (*refspecs) {
fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
"matches on the remote end."));
} else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
"a branch. Because this is not the default configured remote\n"
"for your current branch, you must specify a branch on the command line."),
repo);
} else if (!curr_branch) {
fprintf_ln(stderr, _("You are not currently on a branch."));
fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
fprintf_ln(stderr, _("See git-pull(1) for details."));
fprintf(stderr, "\n");
fprintf_ln(stderr, " git pull <remote> <branch>");
fprintf(stderr, "\n");
} else if (!curr_branch->merge_nr) {
const char *remote_name = NULL;
if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
remote_name = "<remote>";
fprintf_ln(stderr, _("There is no tracking information for the current branch."));
fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
fprintf_ln(stderr, _("See git-pull(1) for details."));
fprintf(stderr, "\n");
fprintf_ln(stderr, " git pull <remote> <branch>");
fprintf(stderr, "\n");
fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:\n"
"\n"
" git branch --set-upstream-to=%s/<branch> %s\n"),
remote_name, curr_branch->name);
} else
fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
"from the remote, but no such ref was fetched."),
*curr_branch->merge_name);
exit(1);
}
/**
* Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
* as a string and `refspecs` as a null-terminated array of strings. If `repo`
* is not provided in argv, it is set to NULL.
*/
static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
const char ***refspecs)
{
if (argc > 0) {
*repo = *argv++;
argc--;
} else
*repo = NULL;
*refspecs = argv;
}
/**
* Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
* repository and refspecs to fetch, or NULL if they are not provided.
*/
static int run_fetch(const char *repo, const char **refspecs)
{
struct argv_array args = ARGV_ARRAY_INIT;
int ret;
argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
/* Shared options */
argv_push_verbosity(&args);
if (opt_progress)
argv_array_push(&args, opt_progress);
/* Options passed to git-fetch */
if (opt_all)
argv_array_push(&args, opt_all);
if (opt_append)
argv_array_push(&args, opt_append);
if (opt_upload_pack)
argv_array_push(&args, opt_upload_pack);
argv_push_force(&args);
if (opt_tags)
argv_array_push(&args, opt_tags);
if (opt_prune)
argv_array_push(&args, opt_prune);
if (opt_recurse_submodules)
argv_array_push(&args, opt_recurse_submodules);
if (opt_dry_run)
argv_array_push(&args, "--dry-run");
if (opt_keep)
argv_array_push(&args, opt_keep);
if (opt_depth)
argv_array_push(&args, opt_depth);
if (opt_unshallow)
argv_array_push(&args, opt_unshallow);
if (opt_update_shallow)
argv_array_push(&args, opt_update_shallow);
if (opt_refmap)
argv_array_push(&args, opt_refmap);
if (repo) {
argv_array_push(&args, repo);
argv_array_pushv(&args, refspecs);
} else if (*refspecs)
die("BUG: refspecs without repo?");
ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
argv_array_clear(&args);
return ret;
}
/**
* "Pulls into void" by branching off merge_head.
*/
static int pull_into_void(const unsigned char *merge_head,
const unsigned char *curr_head)
{
/*
* Two-way merge: we treat the index as based on an empty tree,
* and try to fast-forward to HEAD. This ensures we will not lose
* index/worktree changes that the user already made on the unborn
* branch.
*/
if (checkout_fast_forward(EMPTY_TREE_SHA1_BIN, merge_head, 0))
return 1;
if (update_ref("initial pull", "HEAD", merge_head, curr_head, 0, UPDATE_REFS_DIE_ON_ERR))
return 1;
return 0;
}
/**
* Runs git-merge, returning its exit status.
*/
static int run_merge(void)
{
int ret;
struct argv_array args = ARGV_ARRAY_INIT;
argv_array_pushl(&args, "merge", NULL);
/* Shared options */
argv_push_verbosity(&args);
if (opt_progress)
argv_array_push(&args, opt_progress);
/* Options passed to git-merge */
if (opt_diffstat)
argv_array_push(&args, opt_diffstat);
if (opt_log)
argv_array_push(&args, opt_log);
if (opt_squash)
argv_array_push(&args, opt_squash);
if (opt_commit)
argv_array_push(&args, opt_commit);
if (opt_edit)
argv_array_push(&args, opt_edit);
if (opt_ff)
argv_array_push(&args, opt_ff);
if (opt_verify_signatures)
argv_array_push(&args, opt_verify_signatures);
argv_array_pushv(&args, opt_strategies.argv);
argv_array_pushv(&args, opt_strategy_opts.argv);
if (opt_gpg_sign)
argv_array_push(&args, opt_gpg_sign);
argv_array_push(&args, "FETCH_HEAD");
ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
argv_array_clear(&args);
return ret;
}
int cmd_pull(int argc, const char **argv, const char *prefix)
{
const char *repo, **refspecs;
struct sha1_array merge_heads = SHA1_ARRAY_INIT;
unsigned char orig_head[GIT_SHA1_RAWSZ], curr_head[GIT_SHA1_RAWSZ];
if (!getenv("_GIT_USE_BUILTIN_PULL")) {
const char *path = mkpath("%s/git-pull", git_exec_path());
if (sane_execvp(path, (char **)argv) < 0)
die_errno("could not exec %s", path);
}
argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
parse_repo_refspecs(argc, argv, &repo, &refspecs);
if (!opt_ff)
opt_ff = xstrdup_or_null(config_get_ff());
git_config(git_default_config, NULL);
if (read_cache_unmerged())
die_resolve_conflict("Pull");
if (file_exists(git_path("MERGE_HEAD")))
die_conclude_merge();
if (get_sha1("HEAD", orig_head))
hashclr(orig_head);
if (run_fetch(repo, refspecs))
return 1;
if (opt_dry_run)
return 0;
if (get_sha1("HEAD", curr_head))
hashclr(curr_head);
if (!is_null_sha1(orig_head) && !is_null_sha1(curr_head) &&
hashcmp(orig_head, curr_head)) {
/*
* The fetch involved updating the current branch.
*
* The working tree and the index file are still based on
* orig_head commit, but we are merging into curr_head.
* Update the working tree to match curr_head.
*/
warning(_("fetch updated the current branch head.\n"
"fast-forwarding your working tree from\n"
"commit %s."), sha1_to_hex(orig_head));
if (checkout_fast_forward(orig_head, curr_head, 0))
die(_("Cannot fast-forward your working tree.\n"
"After making sure that you saved anything precious from\n"
"$ git diff %s\n"
"output, run\n"
"$ git reset --hard\n"
"to recover."), sha1_to_hex(orig_head));
}
get_merge_heads(&merge_heads);
if (!merge_heads.nr)
die_no_merge_candidates(repo, refspecs);
if (is_null_sha1(orig_head)) {
if (merge_heads.nr > 1)
die(_("Cannot merge multiple branches into empty head."));
return pull_into_void(*merge_heads.sha1, curr_head);
} else
return run_merge();
}
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