signature=a92c1de303af8c03b5c278210d6d213d,git/merge.c at 14c63a9dc093d6738454f6369a4f5663ca732cf7 ·...

/*

* Builtin "git merge"

*

* Copyright (c) 2008 Miklos Vajna

*

* 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 [] [...]"),

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 ) 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 ^^^.. or ~ */

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 ...~ */

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, "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.hash, parents,

result_commit.hash, 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->hash, parents,

result_commit.hash, 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 ', 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;

}