/*

* Builtin "git merge"

*

* Copyright (c) 2008 Miklos Vajna <vmiklos@frugalware.org>

*

* Based on git-merge.sh by Junio C Hamano.

*/

#include "cache.h"

#include "parse-options.h"

#include "builtin.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"

#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[] = {

"git merge [options] <remote>...",

"git merge [options] <msg> HEAD <remote>",

NULL

};

static int show_diffstat = 1, option_log, squash;

static int option_commit = 1, allow_fast_forward = 1;

static int fast_forward_only;

static int allow_trivial = 1, have_message;

static struct strbuf merge_msg;

static struct commit_list *remoteheads;

static unsigned char head[20], stash[20];

static struct strategy **use_strategies;

static size_t use_strategies_nr, use_strategies_alloc;

static const char *branch;

static int verbosity;

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;

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);

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_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,

"do not show a diffstat at the end of the merge",

PARSE_OPT_NOARG, option_parse_n },

OPT_BOOLEAN(0, "stat", &show_diffstat,

"show a diffstat at the end of the merge"),

OPT_BOOLEAN(0, "summary", &show_diffstat, "(synonym to --stat)"),

OPT_BOOLEAN(0, "log", &option_log,

"add list of one-line log to merge commit message"),

OPT_BOOLEAN(0, "squash", &squash,

"create a single commit instead of doing a merge"),

OPT_BOOLEAN(0, "commit", &option_commit,

"perform a commit if the merge succeeds (default)"),

OPT_BOOLEAN(0, "ff", &allow_fast_forward,

"allow fast-forward (default)"),

OPT_BOOLEAN(0, "ff-only", &fast_forward_only,

"abort if fast-forward is not possible"),

OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",

"merge strategy to use", option_parse_strategy),

OPT_CALLBACK('m', "message", &merge_msg, "message",

"message to be used for the merge commit (if any)",

option_parse_message),

OPT__VERBOSITY(&verbosity),

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 void save_state(void)

{

int len;

struct child_process cp;

struct strbuf buffer = STRBUF_INIT;

const char *argv[] = {"stash", "create", NULL};

memset(&cp, 0, sizeof(cp));

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)

return;

strbuf_setlen(&buffer, buffer.len-1);

if (get_sha1(buffer.buf, stash))

die("not a valid object: %s", buffer.buf);

}

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(void)

{

struct strbuf sb = STRBUF_INIT;

const char *args[] = { "stash", "apply", NULL, NULL };

if (is_null_sha1(stash))

return;

reset_hard(head, 1);

args[2] = sha1_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(void)

{

struct rev_info rev;

struct commit *commit;

struct strbuf out = STRBUF_INIT;

struct commit_list *j;

int fd;

struct pretty_print_context ctx = {0};

printf("Squash commit -- not updating HEAD\n");

fd = open(git_path("SQUASH_MSG"), O_WRONLY | O_CREAT, 0666);

if (fd < 0)

die_errno("Could not write to '%s'", git_path("SQUASH_MSG"));

init_revisions(&rev, NULL);

rev.ignore_merges = 1;

rev.commit_format = CMIT_FMT_MEDIUM;

commit = lookup_commit(head);

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;

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",

sha1_to_hex(commit->object.sha1));

pretty_print_commit(rev.commit_format, commit, &out, &ctx);

}

if (write(fd, out.buf, out.len) < 0)

die_errno("Writing SQUASH_MSG");

if (close(fd))

die_errno("Finishing SQUASH_MSG");

strbuf_release(&out);

}

static void finish(const unsigned char *new_head, const char *msg)

{

struct strbuf reflog_message = STRBUF_INIT;

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();

} 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,

DIE_ON_ERR);

/*

* We ignore errors in 'gc --auto', since the

* user should see them.

*/

run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);

}

}

if (new_head && show_diffstat) {

struct diff_options opts;

diff_setup(&opts);

opts.output_format |=

DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;

opts.detect_rename = DIFF_DETECT_RENAME;

if (diff_use_color_default > 0)

DIFF_OPT_SET(&opts, COLOR_DIFF);

if (diff_setup_done(&opts) < 0)

die("diff_setup_done failed");

diff_tree_sha1(head, new_head, "", &opts);

diffcore_std(&opts);

diff_flush(&opts);

}

/* Run a post-merge hook */

run_hook(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 object *remote_head;

unsigned char branch_head[20], buf_sha[20];

struct strbuf buf = STRBUF_INIT;

struct strbuf bname = STRBUF_INIT;

const char *ptr;

char *found_ref;

int len, early;

strbuf_branchname(&bname, remote);

remote = bname.buf;

memset(branch_head, 0, sizeof(branch_head));

remote_head = peel_to_type(remote, 0, NULL, OBJ_COMMIT);

if (!remote_head)

die("'%s' does not point to a commit", remote);

if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {

if (!prefixcmp(found_ref, "refs/heads/")) {

strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",

sha1_to_hex(branch_head), remote);

goto cleanup;

}

if (!prefixcmp(found_ref, "refs/remotes/")) {

strbuf_addf(msg, "%s\t\tremote branch '%s' of .\n",

sha1_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_addstr(&truname, "refs/heads/");

strbuf_addstr(&truname, remote);

strbuf_setlen(&truname, truname.len - len);

if (resolve_ref(truname.buf, buf_sha, 0, NULL)) {

strbuf_addf(msg,

"%s\t\tbranch '%s'%s of .\n",

sha1_to_hex(remote_head->sha1),

truname.buf + 11,

(early ? " (early part)" : ""));

strbuf_release(&truname);

goto cleanup;

}

}

if (!strcmp(remote, "FETCH_HEAD") &&

!access(git_path("FETCH_HEAD"), R_OK)) {

FILE *fp;

struct strbuf line = STRBUF_INIT;

char *ptr;

fp = fopen(git_path("FETCH_HEAD"), "r");

if (!fp)

die_errno("could not open '%s' for reading",

git_path("FETCH_HEAD"));

strbuf_getline(&line, fp, '\n');

fclose(fp);

ptr = strstr(line.buf, "\tnot-for-merge\t");

if (ptr)

strbuf_remove(&line, ptr-line.buf+1, 13);

strbuf_addbuf(msg, &line);

strbuf_release(&line);

goto cleanup;

}

strbuf_addf(msg, "%s\t\tcommit '%s'\n",

sha1_to_hex(remote_head->sha1), remote);

cleanup:

strbuf_release(&buf);

strbuf_release(&bname);

}

static int git_merge_config(const char *k, const char *v, void *cb)

{

if (branch && !prefixcmp(k, "branch.") &&

!prefixcmp(k + 7, branch) &&

!strcmp(k + 7 + strlen(branch), ".mergeoptions")) {

const char **argv;

int argc;

char *buf;

buf = xstrdup(v);

argc = split_cmdline(buf, &argv);

if (argc < 0)

die("Bad branch.%s.mergeoptions string", branch);

argv = xrealloc(argv, sizeof(*argv) * (argc + 2));

memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));

argc++;

parse_options(argc, argv, NULL, builtin_merge_options,

builtin_merge_usage, 0);

free(buf);

}

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.log") || !strcmp(k, "merge.summary"))

option_log = git_config_bool(k, v);

return git_diff_ui_config(k, v, cb);

}

static int read_tree_trivial(unsigned char *common, unsigned char *head,

unsigned char *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(unsigned char *sha1)

{

if (write_cache_as_tree(sha1, 0, NULL))

die("git write-tree failed to write a tree");

}

static int try_merge_strategy(const char *strategy, struct commit_list *common,

const char *head_arg)

{

const char **args;

int i = 0, ret;

struct commit_list *j;

struct strbuf buf = STRBUF_INIT;

int index_fd;

struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));

index_fd = hold_locked_index(lock, 1);

refresh_cache(REFRESH_QUIET);

if (active_cache_changed &&

(write_cache(index_fd, active_cache, active_nr) ||

commit_locked_index(lock)))

return error("Unable to write index.");

rollback_lock_file(lock);

if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {

int clean;

struct commit *result;

struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));

int index_fd;

struct commit_list *reversed = NULL;

struct merge_options o;

if (remoteheads->next) {

error("Not handling anything other than two heads merge.");

return 2;

}

init_merge_options(&o);

if (!strcmp(strategy, "subtree"))

o.subtree_merge = 1;

o.branch1 = head_arg;

o.branch2 = remoteheads->item->util;

for (j = common; j; j = j->next)

commit_list_insert(j->item, &reversed);

index_fd = hold_locked_index(lock, 1);

clean = merge_recursive(&o, lookup_commit(head),

remoteheads->item, reversed, &result);

if (active_cache_changed &&

(write_cache(index_fd, active_cache, active_nr) ||

commit_locked_index(lock)))

die ("unable to write %s", get_index_file());

rollback_lock_file(lock);

return clean ? 0 : 1;

} else {

args = xmalloc((4 + commit_list_count(common) +

commit_list_count(remoteheads)) * sizeof(char *));

strbuf_addf(&buf, "merge-%s", strategy);

args[i++] = buf.buf;

for (j = common; j; j = j->next)

args[i++] = xstrdup(sha1_to_hex(j->item->object.sha1));

args[i++] = "--";

args[i++] = head_arg;

for (j = remoteheads; j; j = j->next)

args[i++] = xstrdup(sha1_to_hex(j->item->object.sha1));

args[i] = NULL;

ret = run_command_v_opt(args, RUN_GIT_CMD);

strbuf_release(&buf);

i = 1;

for (j = common; j; j = j->next)

free((void *)args[i++]);

i += 2;

for (j = remoteheads; j; j = j->next)

free((void *)args[i++]);

free(args);

discard_cache();

if (read_cache() < 0)

die("failed to read the cache");

return ret;

}

}

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)

{

const struct index_state *state = &the_index;

int i, ret = 0;

for (i = 0; i < state->cache_nr; i++)

if (ce_stage(state->cache[i]))

ret++;

return ret;

}

static int checkout_fast_forward(unsigned char *head, unsigned char *remote)

{

struct tree *trees[MAX_UNPACK_TREES];

struct unpack_trees_options opts;

struct tree_desc t[MAX_UNPACK_TREES];

int i, fd, nr_trees = 0;

struct dir_struct dir;

struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));

refresh_cache(REFRESH_QUIET);

fd = hold_locked_index(lock_file, 1);

memset(&trees, 0, sizeof(trees));

memset(&opts, 0, sizeof(opts));

memset(&t, 0, sizeof(t));

memset(&dir, 0, sizeof(dir));

dir.flags |= DIR_SHOW_IGNORED;

dir.exclude_per_dir = ".gitignore";

opts.dir = &dir;

opts.head_idx = 1;

opts.src_index = &the_index;

opts.dst_index = &the_index;

opts.update = 1;

opts.verbose_update = 1;

opts.merge = 1;

opts.fn = twoway_merge;

opts.msgs = get_porcelain_error_msgs();

trees[nr_trees] = parse_tree_indirect(head);

if (!trees[nr_trees++])

return -1;

trees[nr_trees] = parse_tree_indirect(remote);

if (!trees[nr_trees++])

return -1;

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;

if (write_cache(fd, active_cache, active_nr) ||

commit_locked_index(lock_file))

die("unable to write new index file");

return 0;

}

static void split_merge_strategies(const char *string, struct strategy **list,

int *nr, int *alloc)

{

char *p, *q, *buf;

if (!string)

return;

buf = xstrdup(string);

q = buf;

for (;;) {

p = strchr(q, ' ');

if (!p) {

ALLOC_GROW(*list, *nr + 1, *alloc);

(*list)[(*nr)++].name = xstrdup(q);

free(buf);

return;

} else {

*p = '\0';

ALLOC_GROW(*list, *nr + 1, *alloc);

(*list)[(*nr)++].name = xstrdup(q);

q = ++p;

}

}

}

static void add_strategies(const char *string, unsigned attr)

{

struct strategy *list = NULL;

int list_alloc = 0, list_nr = 0, i;

memset(&list, 0, sizeof(list));

split_merge_strategies(string, &list, &list_nr, &list_alloc);

if (list) {

for (i = 0; i < list_nr; i++)

append_strategy(get_strategy(list[i].name));

return;

}

for (i = 0; i < ARRAY_SIZE(all_strategy); i++)

if (all_strategy[i].attr & attr)

append_strategy(&all_strategy[i]);

}

static int merge_trivial(void)

{

unsigned char result_tree[20], result_commit[20];

struct commit_list *parent = xmalloc(sizeof(*parent));

write_tree_trivial(result_tree);

printf("Wonderful.\n");

parent->item = lookup_commit(head);

parent->next = xmalloc(sizeof(*parent->next));

parent->next->item = remoteheads->item;

parent->next->next = NULL;

commit_tree(merge_msg.buf, result_tree, parent, result_commit, NULL);

finish(result_commit, "In-index merge");

drop_save();

return 0;

}

static int finish_automerge(struct commit_list *common,

unsigned char *result_tree,

const char *wt_strategy)

{

struct commit_list *parents = NULL, *j;

struct strbuf buf = STRBUF_INIT;

unsigned char result_commit[20];

free_commit_list(common);

if (allow_fast_forward) {

parents = remoteheads;

commit_list_insert(lookup_commit(head), &parents);

parents = reduce_heads(parents);

} else {

struct commit_list **pptr = &parents;

pptr = &commit_list_insert(lookup_commit(head),

pptr)->next;

for (j = remoteheads; j; j = j->next)

pptr = &commit_list_insert(j->item, pptr)->next;

}

free_commit_list(remoteheads);

strbuf_addch(&merge_msg, '\n');

commit_tree(merge_msg.buf, result_tree, parents, result_commit, NULL);

strbuf_addf(&buf, "Merge made by %s.", wt_strategy);

finish(result_commit, buf.buf);

strbuf_release(&buf);

drop_save();

return 0;

}

static int suggest_conflicts(void)

{

FILE *fp;

int pos;

fp = fopen(git_path("MERGE_MSG"), "a");

if (!fp)

die_errno("Could not open '%s' for writing",

git_path("MERGE_MSG"));

fprintf(fp, "\nConflicts:\n");

for (pos = 0; pos < active_nr; pos++) {

struct cache_entry *ce = active_cache[pos];

if (ce_stage(ce)) {

fprintf(fp, "\t%s\n", ce->name);

while (pos + 1 < active_nr &&

!strcmp(ce->name,

active_cache[pos + 1]->name))

pos++;

}

}

fclose(fp);

rerere();

printf("Automatic merge failed; "

"fix conflicts and then commit the result.\n");

return 1;

}

static struct commit *is_old_style_invocation(int argc, const char **argv)

{

struct commit *second_token = NULL;

if (argc > 2) {

unsigned char second_sha1[20];

if (get_sha1(argv[1], second_sha1))

return NULL;

second_token = lookup_commit_reference_gently(second_sha1, 0);

if (!second_token)

die("'%s' is not a commit", argv[1]);

if (hashcmp(second_token->object.sha1, head))

return NULL;

}

return second_token;

}

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;

}

int cmd_merge(int argc, const char **argv, const char *prefix)

{

unsigned char result_tree[20];

struct strbuf buf = STRBUF_INIT;

const char *head_arg;

int flag, head_invalid = 0, i;

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 **remotes = &remoteheads;

if (file_exists(git_path("MERGE_HEAD")))

die("You have not concluded your merge. (MERGE_HEAD exists)");

if (read_cache_unmerged())

die("You are in the middle of a conflicted merge."

" (index unmerged)");

/*

* Check if we are _not_ on a detached HEAD, i.e. if there is a

* current branch.

*/

branch = resolve_ref("HEAD", head, 0, &flag);

if (branch && !prefixcmp(branch, "refs/heads/"))

branch += 11;

if (is_null_sha1(head))

head_invalid = 1;

git_config(git_merge_config, NULL);

/* for color.ui */

if (diff_use_color_default == -1)

diff_use_color_default = git_use_color_default;

argc = parse_options(argc, argv, prefix, builtin_merge_options,

builtin_merge_usage, 0);

if (verbosity < 0)

show_diffstat = 0;

if (squash) {

if (!allow_fast_forward)

die("You cannot combine --squash with --no-ff.");

option_commit = 0;

}

if (!allow_fast_forward && fast_forward_only)

die("You cannot combine --no-ff with --ff-only.");

if (!argc)

usage_with_options(builtin_merge_usage,

builtin_merge_options);

/*

* This could be traditional "merge <msg> HEAD <commit>..." and

* the way we can tell it is to see if the second token is HEAD,

* but some people might have misused the interface and used a

* committish that is the same as HEAD there instead.

* Traditional format never would have "-m" so it is an

* additional safety measure to check for it.

*/

if (!have_message && is_old_style_invocation(argc, argv)) {

strbuf_addstr(&merge_msg, argv[0]);

head_arg = argv[1];

argv += 2;

argc -= 2;

} else if (head_invalid) {

struct object *remote_head;

/*

* 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".

*/

if (argc != 1)

die("Can merge only exactly one commit into "

"empty head");

if (squash)

die("Squash commit into empty head not supported yet");

if (!allow_fast_forward)

die("Non-fast-forward commit does not make sense into "

"an empty head");

remote_head = peel_to_type(argv[0], 0, NULL, OBJ_COMMIT);

if (!remote_head)

die("%s - not something we can merge", argv[0]);

update_ref("initial pull", "HEAD", remote_head->sha1, NULL, 0,

DIE_ON_ERR);

reset_hard(remote_head->sha1, 0);

return 0;

} else {

struct strbuf msg = STRBUF_INIT;

/* We are invoked directly as the first-class UI. */

head_arg = "HEAD";

/*

* All the rest are the commits being merged;

* prepare the standard merge summary message to

* be appended to the given message. If remote

* is invalid we will die later in the common

* codepath so we discard the error in this

* loop.

*/

if (!have_message) {

for (i = 0; i < argc; i++)

merge_name(argv[i], &msg);

fmt_merge_msg(option_log, &msg, &merge_msg);

if (merge_msg.len)

strbuf_setlen(&merge_msg, merge_msg.len-1);

}

}

if (head_invalid || !argc)

usage_with_options(builtin_merge_usage,

builtin_merge_options);

strbuf_addstr(&buf, "merge");

for (i = 0; i < argc; i++)

strbuf_addf(&buf, " %s", argv[i]);

setenv("GIT_REFLOG_ACTION", buf.buf, 0);

strbuf_reset(&buf);

for (i = 0; i < argc; i++) {

struct object *o;

struct commit *commit;

o = peel_to_type(argv[i], 0, NULL, OBJ_COMMIT);

if (!o)

die("%s - not something we can merge", argv[i]);

commit = lookup_commit(o->sha1);

commit->util = (void *)argv[i];

remotes = &commit_list_insert(commit, remotes)->next;

strbuf_addf(&buf, "GITHEAD_%s", sha1_to_hex(o->sha1));

setenv(buf.buf, argv[i], 1);

strbuf_reset(&buf);

}

if (!use_strategies) {

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)

allow_fast_forward = 0;

if (use_strategies[i]->attr & NO_TRIVIAL)

allow_trivial = 0;

}

if (!remoteheads->next)

common = get_merge_bases(lookup_commit(head),

remoteheads->item, 1);

else {

struct commit_list *list = remoteheads;

commit_list_insert(lookup_commit(head), &list);

common = get_octopus_merge_bases(list);

free(list);

}

update_ref("updating ORIG_HEAD", "ORIG_HEAD", head, NULL, 0,

DIE_ON_ERR);