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/*
* Builtin "git merge"
*
* Copyright (c) 2008 Miklos Vajna <vmiklos@frugalware.org>
*
* Based on git-merge.sh by Junio C Hamano.
*/
#include "cache.h"
#include "config.h"
#include "parse-options.h"
#include "builtin.h"
#include "lockfile.h"
#include "run-command.h"
#include "diff.h"
#include "refs.h"
#include "commit.h"
#include "diffcore.h"
#include "revision.h"
#include "unpack-trees.h"
#include "cache-tree.h"
#include "dir.h"
#include "utf8.h"
#include "log-tree.h"
#include "color.h"
#include "rerere.h"
#include "help.h"
#include "merge-recursive.h"
#include "resolve-undo.h"
#include "remote.h"
#include "fmt-merge-msg.h"
#include "gpg-interface.h"
#include "sequencer.h"
#include "string-list.h"
#include "packfile.h"
#define DEFAULT_TWOHEAD (1<<0)
#define DEFAULT_OCTOPUS (1<<1)
#define NO_FAST_FORWARD (1<<2)
#define NO_TRIVIAL (1<<3)
struct strategy {
const char *name;
unsigned attr;
};
static const char * const builtin_merge_usage[] = {
N_("git merge [<options>] [<commit>...]"),
N_("git merge --abort"),
N_("git merge --continue"),
NULL
};
static int show_diffstat = 1, shortlog_len = -1, squash;
static int option_commit = 1;
static int option_edit = -1;
static int allow_trivial = 1, have_message, verify_signatures;
static int overwrite_ignore = 1;
static struct strbuf merge_msg = STRBUF_INIT;
static struct strategy **use_strategies;
static size_t use_strategies_nr, use_strategies_alloc;
static const char **xopts;
static size_t xopts_nr, xopts_alloc;
static const char *branch;
static char *branch_mergeoptions;
static int option_renormalize;
static int verbosity;
static int allow_rerere_auto;
static int abort_current_merge;
static int continue_current_merge;
static int allow_unrelated_histories;
static int show_progress = -1;
static int default_to_upstream = 1;
static int signoff;
static const char *sign_commit;
static int verify_msg = 1;
static struct strategy all_strategy[] = {
{ "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
{ "octopus", DEFAULT_OCTOPUS },
{ "resolve", 0 },
{ "ours", NO_FAST_FORWARD | NO_TRIVIAL },
{ "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
};
static const char *pull_twohead, *pull_octopus;
enum ff_type {
FF_NO,
FF_ALLOW,
FF_ONLY
};
static enum ff_type fast_forward = FF_ALLOW;
static int option_parse_message(const struct option *opt,
const char *arg, int unset)
{
struct strbuf *buf = opt->value;
if (unset)
strbuf_setlen(buf, 0);
else if (arg) {
strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
have_message = 1;
} else
return error(_("switch `m' requires a value"));
return 0;
}
static struct strategy *get_strategy(const char *name)
{
int i;
struct strategy *ret;
static struct cmdnames main_cmds, other_cmds;
static int loaded;
if (!name)
return NULL;
for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
if (!strcmp(name, all_strategy[i].name))
return &all_strategy[i];
if (!loaded) {
struct cmdnames not_strategies;
loaded = 1;
memset(&not_strategies, 0, sizeof(struct cmdnames));
load_command_list("git-merge-", &main_cmds, &other_cmds);
for (i = 0; i < main_cmds.cnt; i++) {
int j, found = 0;
struct cmdname *ent = main_cmds.names[i];
for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
if (!strncmp(ent->name, all_strategy[j].name, ent->len)
&& !all_strategy[j].name[ent->len])
found = 1;
if (!found)
add_cmdname(&not_strategies, ent->name, ent->len);
}
exclude_cmds(&main_cmds, &not_strategies);
}
if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
fprintf(stderr, _("Available strategies are:"));
for (i = 0; i < main_cmds.cnt; i++)
fprintf(stderr, " %s", main_cmds.names[i]->name);
fprintf(stderr, ".\n");
if (other_cmds.cnt) {
fprintf(stderr, _("Available custom strategies are:"));
for (i = 0; i < other_cmds.cnt; i++)
fprintf(stderr, " %s", other_cmds.names[i]->name);
fprintf(stderr, ".\n");
}
exit(1);
}
ret = xcalloc(1, sizeof(struct strategy));
ret->name = xstrdup(name);
ret->attr = NO_TRIVIAL;
return ret;
}
static void append_strategy(struct strategy *s)
{
ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
use_strategies[use_strategies_nr++] = s;
}
static int option_parse_strategy(const struct option *opt,
const char *name, int unset)
{
if (unset)
return 0;
append_strategy(get_strategy(name));
return 0;
}
static int option_parse_x(const struct option *opt,
const char *arg, int unset)
{
if (unset)
return 0;
ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
xopts[xopts_nr++] = xstrdup(arg);
return 0;
}
static int option_parse_n(const struct option *opt,
const char *arg, int unset)
{
show_diffstat = unset;
return 0;
}
static struct option builtin_merge_options[] = {
{ OPTION_CALLBACK, 'n', NULL, NULL, NULL,
N_("do not show a diffstat at the end of the merge"),
PARSE_OPT_NOARG, option_parse_n },
OPT_BOOL(0, "stat", &show_diffstat,
N_("show a diffstat at the end of the merge")),
OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
{ OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
N_("add (at most <n>) entries from shortlog to merge commit message"),
PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
OPT_BOOL(0, "squash", &squash,
N_("create a single commit instead of doing a merge")),
OPT_BOOL(0, "commit", &option_commit,
N_("perform a commit if the merge succeeds (default)")),
OPT_BOOL('e', "edit", &option_edit,
N_("edit message before committing")),
OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
{ OPTION_SET_INT, 0, "ff-only", &fast_forward, NULL,
N_("abort if fast-forward is not possible"),
PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
OPT_BOOL(0, "verify-signatures", &verify_signatures,
N_("verify that the named commit has a valid GPG signature")),
OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
N_("merge strategy to use"), option_parse_strategy),
OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
N_("option for selected merge strategy"), option_parse_x),
OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
N_("merge commit message (for a non-fast-forward merge)"),
option_parse_message),
OPT__VERBOSITY(&verbosity),
OPT_BOOL(0, "abort", &abort_current_merge,
N_("abort the current in-progress merge")),
OPT_BOOL(0, "continue", &continue_current_merge,
N_("continue the current in-progress merge")),
OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
N_("allow merging unrelated histories")),
OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
OPT_BOOL(0, "verify", &verify_msg, N_("verify commit-msg hook")),
OPT_END()
};
/* Cleans up metadata that is uninteresting after a succeeded merge. */
static void drop_save(void)
{
unlink(git_path_merge_head());
unlink(git_path_merge_msg());
unlink(git_path_merge_mode());
}
static int save_state(struct object_id *stash)
{
int len;
struct child_process cp = CHILD_PROCESS_INIT;
struct strbuf buffer = STRBUF_INIT;
const char *argv[] = {"stash", "create", NULL};
int rc = -1;
cp.argv = argv;
cp.out = -1;
cp.git_cmd = 1;
if (start_command(&cp))
die(_("could not run stash."));
len = strbuf_read(&buffer, cp.out, 1024);
close(cp.out);
if (finish_command(&cp) || len < 0)
die(_("stash failed"));
else if (!len) /* no changes */
goto out;
strbuf_setlen(&buffer, buffer.len-1);
if (get_oid(buffer.buf, stash))
die(_("not a valid object: %s"), buffer.buf);
rc = 0;
out:
strbuf_release(&buffer);
return rc;
}
static void read_empty(unsigned const char *sha1, int verbose)
{
int i = 0;
const char *args[7];
args[i++] = "read-tree";
if (verbose)
args[i++] = "-v";
args[i++] = "-m";
args[i++] = "-u";
args[i++] = EMPTY_TREE_SHA1_HEX;
args[i++] = sha1_to_hex(sha1);
args[i] = NULL;
if (run_command_v_opt(args, RUN_GIT_CMD))
die(_("read-tree failed"));
}
static void reset_hard(unsigned const char *sha1, int verbose)
{
int i = 0;
const char *args[6];
args[i++] = "read-tree";
if (verbose)
args[i++] = "-v";
args[i++] = "--reset";
args[i++] = "-u";
args[i++] = sha1_to_hex(sha1);
args[i] = NULL;
if (run_command_v_opt(args, RUN_GIT_CMD))
die(_("read-tree failed"));
}
static void restore_state(const struct object_id *head,
const struct object_id *stash)
{
struct strbuf sb = STRBUF_INIT;
const char *args[] = { "stash", "apply", NULL, NULL };
if (is_null_oid(stash))
return;
reset_hard(head->hash, 1);
args[2] = oid_to_hex(stash);
/*
* It is OK to ignore error here, for example when there was
* nothing to restore.
*/
run_command_v_opt(args, RUN_GIT_CMD);
strbuf_release(&sb);
refresh_cache(REFRESH_QUIET);
}
/* This is called when no merge was necessary. */
static void finish_up_to_date(const char *msg)
{
if (verbosity >= 0)
printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
drop_save();
}
static void squash_message(struct commit *commit, struct commit_list *remoteheads)
{
struct rev_info rev;
struct strbuf out = STRBUF_INIT;
struct commit_list *j;
struct pretty_print_context ctx = {0};
printf(_("Squash commit -- not updating HEAD\n"));
init_revisions(&rev, NULL);
rev.ignore_merges = 1;
rev.commit_format = CMIT_FMT_MEDIUM;
commit->object.flags |= UNINTERESTING;
add_pending_object(&rev, &commit->object, NULL);
for (j = remoteheads; j; j = j->next)
add_pending_object(&rev, &j->item->object, NULL);
setup_revisions(0, NULL, &rev, NULL);
if (prepare_revision_walk(&rev))
die(_("revision walk setup failed"));
ctx.abbrev = rev.abbrev;
ctx.date_mode = rev.date_mode;
ctx.fmt = rev.commit_format;
strbuf_addstr(&out, "Squashed commit of the following:\n");
while ((commit = get_revision(&rev)) != NULL) {
strbuf_addch(&out, '\n');
strbuf_addf(&out, "commit %s\n",
oid_to_hex(&commit->object.oid));
pretty_print_commit(&ctx, commit, &out);
}
write_file_buf(git_path_squash_msg(), out.buf, out.len);
strbuf_release(&out);
}
static void finish(struct commit *head_commit,
struct commit_list *remoteheads,
const struct object_id *new_head, const char *msg)
{
struct strbuf reflog_message = STRBUF_INIT;
const struct object_id *head = &head_commit->object.oid;
if (!msg)
strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
else {
if (verbosity >= 0)
printf("%s\n", msg);
strbuf_addf(&reflog_message, "%s: %s",
getenv("GIT_REFLOG_ACTION"), msg);
}
if (squash) {
squash_message(head_commit, remoteheads);
} else {
if (verbosity >= 0 && !merge_msg.len)
printf(_("No merge message -- not updating HEAD\n"));
else {
const char *argv_gc_auto[] = { "gc", "--auto", NULL };
update_ref(reflog_message.buf, "HEAD", new_head, head,
0, UPDATE_REFS_DIE_ON_ERR);
/*
* We ignore errors in 'gc --auto', since the
* user should see them.
*/
close_all_packs();
run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
}
}
if (new_head && show_diffstat) {
struct diff_options opts;
diff_setup(&opts);
opts.stat_width = -1; /* use full terminal width */
opts.stat_graph_width = -1; /* respect statGraphWidth config */
opts.output_format |=
DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
opts.detect_rename = DIFF_DETECT_RENAME;
diff_setup_done(&opts);
diff_tree_oid(head, new_head, "", &opts);
diffcore_std(&opts);
diff_flush(&opts);
}
/* Run a post-merge hook */
run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
strbuf_release(&reflog_message);
}
/* Get the name for the merge commit's message. */
static void merge_name(const char *remote, struct strbuf *msg)
{
struct commit *remote_head;
struct object_id branch_head;
struct strbuf buf = STRBUF_INIT;
struct strbuf bname = STRBUF_INIT;
const char *ptr;
char *found_ref;
int len, early;
strbuf_branchname(&bname, remote, 0);
remote = bname.buf;
oidclr(&branch_head);
remote_head = get_merge_parent(remote);
if (!remote_head)
die(_("'%s' does not point to a commit"), remote);
if (dwim_ref(remote, strlen(remote), &branch_head, &found_ref) > 0) {
if (starts_with(found_ref, "refs/heads/")) {
strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
oid_to_hex(&branch_head), remote);
goto cleanup;
}
if (starts_with(found_ref, "refs/tags/")) {
strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
oid_to_hex(&branch_head), remote);
goto cleanup;
}
if (starts_with(found_ref, "refs/remotes/")) {
strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
oid_to_hex(&branch_head), remote);
goto cleanup;
}
}
/* See if remote matches <name>^^^.. or <name>~<number> */
for (len = 0, ptr = remote + strlen(remote);
remote < ptr && ptr[-1] == '^';
ptr--)
len++;
if (len)
early = 1;
else {
early = 0;
ptr = strrchr(remote, '~');
if (ptr) {
int seen_nonzero = 0;
len++; /* count ~ */
while (*++ptr && isdigit(*ptr)) {
seen_nonzero |= (*ptr != '0');
len++;
}
if (*ptr)
len = 0; /* not ...~<number> */
else if (seen_nonzero)
early = 1;
else if (len == 1)
early = 1; /* "name~" is "name~1"! */
}
}
if (len) {
struct strbuf truname = STRBUF_INIT;
strbuf_addf(&truname, "refs/heads/%s", remote);
strbuf_setlen(&truname, truname.len - len);
if (ref_exists(truname.buf)) {
strbuf_addf(msg,
"%s\t\tbranch '%s'%s of .\n",
oid_to_hex(&remote_head->object.oid),
truname.buf + 11,
(early ? " (early part)" : ""));
strbuf_release(&truname);
goto cleanup;
}
strbuf_release(&truname);
}
if (remote_head->util) {
struct merge_remote_desc *desc;
desc = merge_remote_util(remote_head);
if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
strbuf_addf(msg, "%s\t\t%s '%s'\n",
oid_to_hex(&desc->obj->oid),
typename(desc->obj->type),
remote);
goto cleanup;
}
}
strbuf_addf(msg, "%s\t\tcommit '%s'\n",
oid_to_hex(&remote_head->object.oid), remote);
cleanup:
strbuf_release(&buf);
strbuf_release(&bname);
}
static void parse_branch_merge_options(char *bmo)
{
const char **argv;
int argc;
if (!bmo)
return;
argc = split_cmdline(bmo, &argv);
if (argc < 0)
die(_("Bad branch.%s.mergeoptions string: %s"), branch,
split_cmdline_strerror(argc));
REALLOC_ARRAY(argv, argc + 2);
MOVE_ARRAY(argv + 1, argv, argc + 1);
argc++;
argv[0] = "branch.*.mergeoptions";
parse_options(argc, argv, NULL, builtin_merge_options,
builtin_merge_usage, 0);
free(argv);
}
static int git_merge_config(const char *k, const char *v, void *cb)
{
int status;
if (branch && starts_with(k, "branch.") &&
starts_with(k + 7, branch) &&
!strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
free(branch_mergeoptions);
branch_mergeoptions = xstrdup(v);
return 0;
}
if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
show_diffstat = git_config_bool(k, v);
else if (!strcmp(k, "merge.verifysignatures"))
verify_signatures = git_config_bool(k, v);
else if (!strcmp(k, "pull.twohead"))
return git_config_string(&pull_twohead, k, v);
else if (!strcmp(k, "pull.octopus"))
return git_config_string(&pull_octopus, k, v);
else if (!strcmp(k, "merge.renormalize"))
option_renormalize = git_config_bool(k, v);
else if (!strcmp(k, "merge.ff")) {
int boolval = git_parse_maybe_bool(v);
if (0 <= boolval) {
fast_forward = boolval ? FF_ALLOW : FF_NO;
} else if (v && !strcmp(v, "only")) {
fast_forward = FF_ONLY;
} /* do not barf on values from future versions of git */
return 0;
} else if (!strcmp(k, "merge.defaulttoupstream")) {
default_to_upstream = git_config_bool(k, v);
return 0;
} else if (!strcmp(k, "commit.gpgsign")) {
sign_commit = git_config_bool(k, v) ? "" : NULL;
return 0;
}
status = fmt_merge_msg_config(k, v, cb);
if (status)
return status;
status = git_gpg_config(k, v, NULL);
if (status)
return status;
return git_diff_ui_config(k, v, cb);
}
static int read_tree_trivial(struct object_id *common, struct object_id *head,
struct object_id *one)
{
int i, nr_trees = 0;
struct tree *trees[MAX_UNPACK_TREES];
struct tree_desc t[MAX_UNPACK_TREES];
struct unpack_trees_options opts;
memset(&opts, 0, sizeof(opts));
opts.head_idx = 2;
opts.src_index = &the_index;
opts.dst_index = &the_index;
opts.update = 1;
opts.verbose_update = 1;
opts.trivial_merges_only = 1;
opts.merge = 1;
trees[nr_trees] = parse_tree_indirect(common);
if (!trees[nr_trees++])
return -1;
trees[nr_trees] = parse_tree_indirect(head);
if (!trees[nr_trees++])
return -1;
trees[nr_trees] = parse_tree_indirect(one);
if (!trees[nr_trees++])
return -1;
opts.fn = threeway_merge;
cache_tree_free(&active_cache_tree);
for (i = 0; i < nr_trees; i++) {
parse_tree(trees[i]);
init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
}
if (unpack_trees(nr_trees, t, &opts))
return -1;
return 0;
}
static void write_tree_trivial(struct object_id *oid)
{
if (write_cache_as_tree(oid->hash, 0, NULL))
die(_("git write-tree failed to write a tree"));
}
static int try_merge_strategy(const char *strategy, struct commit_list *common,
struct commit_list *remoteheads,
struct commit *head)
{
static struct lock_file lock;
const char *head_arg = "HEAD";
hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
refresh_cache(REFRESH_QUIET);
if (active_cache_changed &&
write_locked_index(&the_index, &lock, COMMIT_LOCK))
return error(_("Unable to write index."));
rollback_lock_file(&lock);
if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
int clean, x;
struct commit *result;
struct commit_list *reversed = NULL;
struct merge_options o;
struct commit_list *j;
if (remoteheads->next) {
error(_("Not handling anything other than two heads merge."));
return 2;
}
init_merge_options(&o);
if (!strcmp(strategy, "subtree"))
o.subtree_shift = "";
o.renormalize = option_renormalize;
o.show_rename_progress =
show_progress == -1 ? isatty(2) : show_progress;
for (x = 0; x < xopts_nr; x++)
if (parse_merge_opt(&o, xopts[x]))
die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
o.branch1 = head_arg;
o.branch2 = merge_remote_util(remoteheads->item)->name;
for (j = common; j; j = j->next)
commit_list_insert(j->item, &reversed);
hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
clean = merge_recursive(&o, head,
remoteheads->item, reversed, &result);
if (clean < 0)
exit(128);
if (active_cache_changed &&
write_locked_index(&the_index, &lock, COMMIT_LOCK))
die (_("unable to write %s"), get_index_file());
rollback_lock_file(&lock);
return clean ? 0 : 1;
} else {
return try_merge_command(strategy, xopts_nr, xopts,
common, head_arg, remoteheads);
}
}
static void count_diff_files(struct diff_queue_struct *q,
struct diff_options *opt, void *data)
{
int *count = data;
(*count) += q->nr;
}
static int count_unmerged_entries(void)
{
int i, ret = 0;
for (i = 0; i < active_nr; i++)
if (ce_stage(active_cache[i]))
ret++;
return ret;
}
static void add_strategies(const char *string, unsigned attr)
{
int i;
if (string) {
struct string_list list = STRING_LIST_INIT_DUP;
struct string_list_item *item;
string_list_split(&list, string, ' ', -1);
for_each_string_list_item(item, &list)
append_strategy(get_strategy(item->string));
string_list_clear(&list, 0);
return;
}
for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
if (all_strategy[i].attr & attr)
append_strategy(&all_strategy[i]);
}
static void read_merge_msg(struct strbuf *msg)
{
const char *filename = git_path_merge_msg();
strbuf_reset(msg);
if (strbuf_read_file(msg, filename, 0) < 0)
die_errno(_("Could not read from '%s'"), filename);
}
static void write_merge_state(struct commit_list *);
static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
{
if (err_msg)
error("%s", err_msg);
fprintf(stderr,
_("Not committing merge; use 'git commit' to complete the merge.\n"));
write_merge_state(remoteheads);
exit(1);
}
static const char merge_editor_comment[] =
N_("Please enter a commit message to explain why this merge is necessary,\n"
"especially if it merges an updated upstream into a topic branch.\n"
"\n"
"Lines starting with '%c' will be ignored, and an empty message aborts\n"
"the commit.\n");
static void write_merge_heads(struct commit_list *);
static void prepare_to_commit(struct commit_list *remoteheads)
{
struct strbuf msg = STRBUF_INIT;
strbuf_addbuf(&msg, &merge_msg);
strbuf_addch(&msg, '\n');
if (squash)
BUG("the control must not reach here under --squash");
if (0 < option_edit)
strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
if (signoff)
append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
write_merge_heads(remoteheads);
write_file_buf(git_path_merge_msg(), msg.buf, msg.len);
if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
git_path_merge_msg(), "merge", NULL))
abort_commit(remoteheads, NULL);
if (0 < option_edit) {
if (launch_editor(git_path_merge_msg(), NULL, NULL))
abort_commit(remoteheads, NULL);
}
if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
"commit-msg",
git_path_merge_msg(), NULL))
abort_commit(remoteheads, NULL);
read_merge_msg(&msg);
strbuf_stripspace(&msg, 0 < option_edit);
if (!msg.len)
abort_commit(remoteheads, _("Empty commit message."));
strbuf_release(&merge_msg);
strbuf_addbuf(&merge_msg, &msg);
strbuf_release(&msg);
}
static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
{
struct object_id result_tree, result_commit;
struct commit_list *parents, **pptr = &parents;
static struct lock_file lock;
hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
refresh_cache(REFRESH_QUIET);
if (active_cache_changed &&
write_locked_index(&the_index, &lock, COMMIT_LOCK))
return error(_("Unable to write index."));
rollback_lock_file(&lock);
write_tree_trivial(&result_tree);
printf(_("Wonderful.\n"));
pptr = commit_list_append(head, pptr);
pptr = commit_list_append(remoteheads->item, pptr);
prepare_to_commit(remoteheads);
if (commit_tree(merge_msg.buf, merge_msg.len, &result_tree, parents,
&result_commit, NULL, sign_commit))
die(_("failed to write commit object"));
finish(head, remoteheads, &result_commit, "In-index merge");
drop_save();
return 0;
}
static int finish_automerge(struct commit *head,
int head_subsumed,
struct commit_list *common,
struct commit_list *remoteheads,
struct object_id *result_tree,
const char *wt_strategy)
{
struct commit_list *parents = NULL;
struct strbuf buf = STRBUF_INIT;
struct object_id result_commit;
free_commit_list(common);
parents = remoteheads;
if (!head_subsumed || fast_forward == FF_NO)
commit_list_insert(head, &parents);
strbuf_addch(&merge_msg, '\n');
prepare_to_commit(remoteheads);
if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
&result_commit, NULL, sign_commit))
die(_("failed to write commit object"));
strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
finish(head, remoteheads, &result_commit, buf.buf);
strbuf_release(&buf);
drop_save();
return 0;
}
static int suggest_conflicts(void)
{
const char *filename;
FILE *fp;
struct strbuf msgbuf = STRBUF_INIT;
filename = git_path_merge_msg();
fp = xfopen(filename, "a");
append_conflicts_hint(&msgbuf);
fputs(msgbuf.buf, fp);
strbuf_release(&msgbuf);
fclose(fp);
rerere(allow_rerere_auto);
printf(_("Automatic merge failed; "
"fix conflicts and then commit the result.\n"));
return 1;
}
static int evaluate_result(void)
{
int cnt = 0;
struct rev_info rev;
/* Check how many files differ. */
init_revisions(&rev, "");
setup_revisions(0, NULL, &rev, NULL);
rev.diffopt.output_format |=
DIFF_FORMAT_CALLBACK;
rev.diffopt.format_callback = count_diff_files;
rev.diffopt.format_callback_data = &cnt;
run_diff_files(&rev, 0);
/*
* Check how many unmerged entries are
* there.
*/
cnt += count_unmerged_entries();
return cnt;
}
/*
* Pretend as if the user told us to merge with the remote-tracking
* branch we have for the upstream of the current branch
*/
static int setup_with_upstream(const char ***argv)
{
struct branch *branch = branch_get(NULL);
int i;
const char **args;
if (!branch)
die(_("No current branch."));
if (!branch->remote_name)
die(_("No remote for the current branch."));
if (!branch->merge_nr)
die(_("No default upstream defined for the current branch."));
args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
for (i = 0; i < branch->merge_nr; i++) {
if (!branch->merge[i]->dst)
die(_("No remote-tracking branch for %s from %s"),
branch->merge[i]->src, branch->remote_name);
args[i] = branch->merge[i]->dst;
}
args[i] = NULL;
*argv = args;
return i;
}
static void write_merge_heads(struct commit_list *remoteheads)
{
struct commit_list *j;
struct strbuf buf = STRBUF_INIT;
for (j = remoteheads; j; j = j->next) {
struct object_id *oid;
struct commit *c = j->item;
if (c->util && merge_remote_util(c)->obj) {
oid = &merge_remote_util(c)->obj->oid;
} else {
oid = &c->object.oid;
}
strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
}
write_file_buf(git_path_merge_head(), buf.buf, buf.len);
strbuf_reset(&buf);
if (fast_forward == FF_NO)
strbuf_addstr(&buf, "no-ff");
write_file_buf(git_path_merge_mode(), buf.buf, buf.len);
strbuf_release(&buf);
}
static void write_merge_state(struct commit_list *remoteheads)
{
write_merge_heads(remoteheads);
strbuf_addch(&merge_msg, '\n');
write_file_buf(git_path_merge_msg(), merge_msg.buf, merge_msg.len);
}
static int default_edit_option(void)
{
static const char name[] = "GIT_MERGE_AUTOEDIT";
const char *e = getenv(name);
struct stat st_stdin, st_stdout;
if (have_message)
/* an explicit -m msg without --[no-]edit */
return 0;
if (e) {
int v = git_parse_maybe_bool(e);
if (v < 0)
die(_("Bad value '%s' in environment '%s'"), e, name);
return v;
}
/* Use editor if stdin and stdout are the same and is a tty */
return (!fstat(0, &st_stdin) &&
!fstat(1, &st_stdout) &&
isatty(0) && isatty(1) &&
st_stdin.st_dev == st_stdout.st_dev &&
st_stdin.st_ino == st_stdout.st_ino &&
st_stdin.st_mode == st_stdout.st_mode);
}
static struct commit_list *reduce_parents(struct commit *head_commit,
int *head_subsumed,
struct commit_list *remoteheads)
{
struct commit_list *parents, **remotes;
/*
* Is the current HEAD reachable from another commit being
* merged? If so we do not want to record it as a parent of
* the resulting merge, unless --no-ff is given. We will flip
* this variable to 0 when we find HEAD among the independent
* tips being merged.
*/
*head_subsumed = 1;
/* Find what parents to record by checking independent ones. */
parents = reduce_heads(remoteheads);
free_commit_list(remoteheads);
remoteheads = NULL;
remotes = &remoteheads;
while (parents) {
struct commit *commit = pop_commit(&parents);
if (commit == head_commit)
*head_subsumed = 0;
else
remotes = &commit_list_insert(commit, remotes)->next;
}
return remoteheads;
}
static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
{
struct fmt_merge_msg_opts opts;
memset(&opts, 0, sizeof(opts));
opts.add_title = !have_message;
opts.shortlog_len = shortlog_len;
opts.credit_people = (0 < option_edit);
fmt_merge_msg(merge_names, merge_msg, &opts);
if (merge_msg->len)
strbuf_setlen(merge_msg, merge_msg->len - 1);
}
static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
{
const char *filename;
int fd, pos, npos;
struct strbuf fetch_head_file = STRBUF_INIT;
if (!merge_names)
merge_names = &fetch_head_file;
filename = git_path_fetch_head();
fd = open(filename, O_RDONLY);
if (fd < 0)
die_errno(_("could not open '%s' for reading"), filename);
if (strbuf_read(merge_names, fd, 0) < 0)
die_errno(_("could not read '%s'"), filename);
if (close(fd) < 0)
die_errno(_("could not close '%s'"), filename);
for (pos = 0; pos < merge_names->len; pos = npos) {
struct object_id oid;
char *ptr;
struct commit *commit;
ptr = strchr(merge_names->buf + pos, '\n');
if (ptr)
npos = ptr - merge_names->buf + 1;
else
npos = merge_names->len;
if (npos - pos < GIT_SHA1_HEXSZ + 2 ||
get_oid_hex(merge_names->buf + pos, &oid))
commit = NULL; /* bad */
else if (memcmp(merge_names->buf + pos + GIT_SHA1_HEXSZ, "\t\t", 2))
continue; /* not-for-merge */
else {
char saved = merge_names->buf[pos + GIT_SHA1_HEXSZ];
merge_names->buf[pos + GIT_SHA1_HEXSZ] = '\0';
commit = get_merge_parent(merge_names->buf + pos);
merge_names->buf[pos + GIT_SHA1_HEXSZ] = saved;
}
if (!commit) {
if (ptr)
*ptr = '\0';
die(_("not something we can merge in %s: %s"),
filename, merge_names->buf + pos);
}
remotes = &commit_list_insert(commit, remotes)->next;
}
if (merge_names == &fetch_head_file)
strbuf_release(&fetch_head_file);
}
static struct commit_list *collect_parents(struct commit *head_commit,
int *head_subsumed,
int argc, const char **argv,
struct strbuf *merge_msg)
{
int i;
struct commit_list *remoteheads = NULL;
struct commit_list **remotes = &remoteheads;
struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
if (merge_msg && (!have_message || shortlog_len))
autogen = &merge_names;
if (head_commit)
remotes = &commit_list_insert(head_commit, remotes)->next;
if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
handle_fetch_head(remotes, autogen);
remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
} else {
for (i = 0; i < argc; i++) {
struct commit *commit = get_merge_parent(argv[i]);
if (!commit)
help_unknown_ref(argv[i], "merge",
_("not something we can merge"));
remotes = &commit_list_insert(commit, remotes)->next;
}
remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
if (autogen) {
struct commit_list *p;
for (p = remoteheads; p; p = p->next)
merge_name(merge_remote_util(p->item)->name, autogen);
}
}
if (autogen) {
prepare_merge_message(autogen, merge_msg);
strbuf_release(autogen);
}
return remoteheads;
}
int cmd_merge(int argc, const char **argv, const char *prefix)
{
struct object_id result_tree, stash, head_oid;
struct commit *head_commit;
struct strbuf buf = STRBUF_INIT;
int i, ret = 0, head_subsumed;
int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
struct commit_list *common = NULL;
const char *best_strategy = NULL, *wt_strategy = NULL;
struct commit_list *remoteheads, *p;
void *branch_to_free;
int orig_argc = argc;
if (argc == 2 && !strcmp(argv[1], "-h"))
usage_with_options(builtin_merge_usage, builtin_merge_options);
/*
* Check if we are _not_ on a detached HEAD, i.e. if there is a
* current branch.
*/
branch = branch_to_free = resolve_refdup("HEAD", 0, &head_oid, NULL);
if (branch)
skip_prefix(branch, "refs/heads/", &branch);
if (!branch || is_null_oid(&head_oid))
head_commit = NULL;
else
head_commit = lookup_commit_or_die(&head_oid, "HEAD");
init_diff_ui_defaults();
git_config(git_merge_config, NULL);
if (branch_mergeoptions)
parse_branch_merge_options(branch_mergeoptions);
argc = parse_options(argc, argv, prefix, builtin_merge_options,
builtin_merge_usage, 0);
if (shortlog_len < 0)
shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
if (verbosity < 0 && show_progress == -1)
show_progress = 0;
if (abort_current_merge) {
int nargc = 2;
const char *nargv[] = {"reset", "--merge", NULL};
if (orig_argc != 2)
usage_msg_opt(_("--abort expects no arguments"),
builtin_merge_usage, builtin_merge_options);
if (!file_exists(git_path_merge_head()))
die(_("There is no merge to abort (MERGE_HEAD missing)."));
/* Invoke 'git reset --merge' */
ret = cmd_reset(nargc, nargv, prefix);
goto done;
}
if (continue_current_merge) {
int nargc = 1;
const char *nargv[] = {"commit", NULL};
if (orig_argc != 2)
usage_msg_opt(_("--continue expects no arguments"),
builtin_merge_usage, builtin_merge_options);
if (!file_exists(git_path_merge_head()))
die(_("There is no merge in progress (MERGE_HEAD missing)."));
/* Invoke 'git commit' */
ret = cmd_commit(nargc, nargv, prefix);
goto done;
}
if (read_cache_unmerged())
die_resolve_conflict("merge");
if (file_exists(git_path_merge_head())) {
/*
* There is no unmerged entry, don't advise 'git
* add/rm <file>', just 'git commit'.
*/
if (advice_resolve_conflict)
die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
"Please, commit your changes before you merge."));
else
die(_("You have not concluded your merge (MERGE_HEAD exists)."));
}
if (file_exists(git_path_cherry_pick_head())) {
if (advice_resolve_conflict)
die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
"Please, commit your changes before you merge."));
else
die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
}
resolve_undo_clear();
if (verbosity < 0)
show_diffstat = 0;
if (squash) {
if (fast_forward == FF_NO)
die(_("You cannot combine --squash with --no-ff."));
option_commit = 0;
}
if (!argc) {
if (default_to_upstream)
argc = setup_with_upstream(&argv);
else
die(_("No commit specified and merge.defaultToUpstream not set."));
} else if (argc == 1 && !strcmp(argv[0], "-")) {
argv[0] = "@{-1}";
}
if (!argc)
usage_with_options(builtin_merge_usage,
builtin_merge_options);
if (!head_commit) {
/*
* If the merged head is a valid one there is no reason
* to forbid "git merge" into a branch yet to be born.
* We do the same for "git pull".
*/
struct object_id *remote_head_oid;
if (squash)
die(_("Squash commit into empty head not supported yet"));
if (fast_forward == FF_NO)
die(_("Non-fast-forward commit does not make sense into "
"an empty head"));
remoteheads = collect_parents(head_commit, &head_subsumed,
argc, argv, NULL);
if (!remoteheads)
die(_("%s - not something we can merge"), argv[0]);
if (remoteheads->next)
die(_("Can merge only exactly one commit into empty head"));
remote_head_oid = &remoteheads->item->object.oid;
read_empty(remote_head_oid->hash, 0);
update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
UPDATE_REFS_DIE_ON_ERR);
goto done;
}
/*
* All the rest are the commits being merged; prepare
* the standard merge summary message to be appended
* to the given message.
*/
remoteheads = collect_parents(head_commit, &head_subsumed,
argc, argv, &merge_msg);
if (!head_commit || !argc)
usage_with_options(builtin_merge_usage,
builtin_merge_options);
if (verify_signatures) {
for (p = remoteheads; p; p = p->next) {
struct commit *commit = p->item;
char hex[GIT_MAX_HEXSZ + 1];
struct signature_check signature_check;
memset(&signature_check, 0, sizeof(signature_check));
check_commit_signature(commit, &signature_check);
find_unique_abbrev_r(hex, commit->object.oid.hash, DEFAULT_ABBREV);
switch (signature_check.result) {
case 'G':
break;
case 'U':
die(_("Commit %s has an untrusted GPG signature, "
"allegedly by %s."), hex, signature_check.signer);
case 'B':
die(_("Commit %s has a bad GPG signature "
"allegedly by %s."), hex, signature_check.signer);
default: /* 'N' */
die(_("Commit %s does not have a GPG signature."), hex);
}
if (verbosity >= 0 && signature_check.result == 'G')
printf(_("Commit %s has a good GPG signature by %s\n"),
hex, signature_check.signer);
signature_check_clear(&signature_check);
}
}
strbuf_addstr(&buf, "merge");
for (p = remoteheads; p; p = p->next)
strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
setenv("GIT_REFLOG_ACTION", buf.buf, 0);
strbuf_reset(&buf);
for (p = remoteheads; p; p = p->next) {
struct commit *commit = p->item;
strbuf_addf(&buf, "GITHEAD_%s",
oid_to_hex(&commit->object.oid));
setenv(buf.buf, merge_remote_util(commit)->name, 1);
strbuf_reset(&buf);
if (fast_forward != FF_ONLY &&
merge_remote_util(commit) &&
merge_remote_util(commit)->obj &&
merge_remote_util(commit)->obj->type == OBJ_TAG)
fast_forward = FF_NO;
}
if (option_edit < 0)
option_edit = default_edit_option();
if (!use_strategies) {
if (!remoteheads)
; /* already up-to-date */
else if (!remoteheads->next)
add_strategies(pull_twohead, DEFAULT_TWOHEAD);
else
add_strategies(pull_octopus, DEFAULT_OCTOPUS);
}
for (i = 0; i < use_strategies_nr; i++) {
if (use_strategies[i]->attr & NO_FAST_FORWARD)
fast_forward = FF_NO;
if (use_strategies[i]->attr & NO_TRIVIAL)
allow_trivial = 0;
}
if (!remoteheads)
; /* already up-to-date */
else if (!remoteheads->next)
common = get_merge_bases(head_commit, remoteheads->item);
else {
struct commit_list *list = remoteheads;
commit_list_insert(head_commit, &list);
common = get_octopus_merge_bases(list);
free(list);
}
update_ref("updating ORIG_HEAD", "ORIG_HEAD",
&head_commit->object.oid, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
if (remoteheads && !common) {
/* No common ancestors found. */
if (!allow_unrelated_histories)
die(_("refusing to merge unrelated histories"));
/* otherwise, we need a real merge. */
} else if (!remoteheads ||
(!remoteheads->next && !common->next &&
common->item == remoteheads->item)) {
/*
* If head can reach all the merge then we are up to date.
* but first the most common case of merging one remote.
*/
finish_up_to_date(_("Already up to date."));
goto done;
} else if (fast_forward != FF_NO && !remoteheads->next &&
!common->next &&
!oidcmp(&common->item->object.oid, &head_commit->object.oid)) {
/* Again the most common case of merging one remote. */
struct strbuf msg = STRBUF_INIT;
struct commit *commit;
if (verbosity >= 0) {
printf(_("Updating %s..%s\n"),
find_unique_abbrev(head_commit->object.oid.hash,
DEFAULT_ABBREV),
find_unique_abbrev(remoteheads->item->object.oid.hash,
DEFAULT_ABBREV));
}
strbuf_addstr(&msg, "Fast-forward");
if (have_message)
strbuf_addstr(&msg,
" (no commit created; -m option ignored)");
commit = remoteheads->item;
if (!commit) {
ret = 1;
goto done;
}
if (checkout_fast_forward(&head_commit->object.oid,
&commit->object.oid,
overwrite_ignore)) {
ret = 1;
goto done;
}
finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
drop_save();
goto done;
} else if (!remoteheads->next && common->next)
;
/*
* We are not doing octopus and not fast-forward. Need
* a real merge.
*/
else if (!remoteheads->next && !common->next && option_commit) {
/*
* We are not doing octopus, not fast-forward, and have
* only one common.
*/
refresh_cache(REFRESH_QUIET);
if (allow_trivial && fast_forward != FF_ONLY) {
/* See if it is really trivial. */
git_committer_info(IDENT_STRICT);
printf(_("Trying really trivial in-index merge...\n"));
if (!read_tree_trivial(&common->item->object.oid,
&head_commit->object.oid,
&remoteheads->item->object.oid)) {
ret = merge_trivial(head_commit, remoteheads);
goto done;
}
printf(_("Nope.\n"));
}
} else {
/*
* An octopus. If we can reach all the remote we are up
* to date.
*/
int up_to_date = 1;
struct commit_list *j;
for (j = remoteheads; j; j = j->next) {
struct commit_list *common_one;
/*
* Here we *have* to calculate the individual
* merge_bases again, otherwise "git merge HEAD^
* HEAD^^" would be missed.
*/
common_one = get_merge_bases(head_commit, j->item);
if (oidcmp(&common_one->item->object.oid, &j->item->object.oid)) {
up_to_date = 0;
break;
}
}
if (up_to_date) {
finish_up_to_date(_("Already up to date. Yeeah!"));
goto done;
}
}
if (fast_forward == FF_ONLY)
die(_("Not possible to fast-forward, aborting."));
/* We are going to make a new commit. */
git_committer_info(IDENT_STRICT);
/*
* At this point, we need a real merge. No matter what strategy
* we use, it would operate on the index, possibly affecting the
* working tree, and when resolved cleanly, have the desired
* tree in the index -- this means that the index must be in
* sync with the head commit. The strategies are responsible
* to ensure this.
*/
if (use_strategies_nr == 1 ||
/*
* Stash away the local changes so that we can try more than one.
*/
save_state(&stash))
oidclr(&stash);
for (i = 0; i < use_strategies_nr; i++) {
int ret;
if (i) {
printf(_("Rewinding the tree to pristine...\n"));
restore_state(&head_commit->object.oid, &stash);
}
if (use_strategies_nr != 1)
printf(_("Trying merge strategy %s...\n"),
use_strategies[i]->name);
/*
* Remember which strategy left the state in the working
* tree.
*/
wt_strategy = use_strategies[i]->name;
ret = try_merge_strategy(use_strategies[i]->name,
common, remoteheads,
head_commit);
if (!option_commit && !ret) {
merge_was_ok = 1;
/*
* This is necessary here just to avoid writing
* the tree, but later we will *not* exit with
* status code 1 because merge_was_ok is set.
*/
ret = 1;
}
if (ret) {
/*
* The backend exits with 1 when conflicts are
* left to be resolved, with 2 when it does not
* handle the given merge at all.
*/
if (ret == 1) {
int cnt = evaluate_result();
if (best_cnt <= 0 || cnt <= best_cnt) {
best_strategy = use_strategies[i]->name;
best_cnt = cnt;
}
}
if (merge_was_ok)
break;
else
continue;
}
/* Automerge succeeded. */
write_tree_trivial(&result_tree);
automerge_was_ok = 1;
break;
}
/*
* If we have a resulting tree, that means the strategy module
* auto resolved the merge cleanly.
*/
if (automerge_was_ok) {
ret = finish_automerge(head_commit, head_subsumed,
common, remoteheads,
&result_tree, wt_strategy);
goto done;
}
/*
* Pick the result from the best strategy and have the user fix
* it up.
*/
if (!best_strategy) {
restore_state(&head_commit->object.oid, &stash);
if (use_strategies_nr > 1)
fprintf(stderr,
_("No merge strategy handled the merge.\n"));
else
fprintf(stderr, _("Merge with strategy %s failed.\n"),
use_strategies[0]->name);
ret = 2;
goto done;
} else if (best_strategy == wt_strategy)
; /* We already have its result in the working tree. */
else {
printf(_("Rewinding the tree to pristine...\n"));
restore_state(&head_commit->object.oid, &stash);
printf(_("Using the %s to prepare resolving by hand.\n"),
best_strategy);
try_merge_strategy(best_strategy, common, remoteheads,
head_commit);
}
if (squash)
finish(head_commit, remoteheads, NULL, NULL);
else
write_merge_state(remoteheads);
if (merge_was_ok)
fprintf(stderr, _("Automatic merge went well; "
"stopped before committing as requested\n"));
else
ret = suggest_conflicts();
done:
free(branch_to_free);
return ret;
}