@@ -0,0 +1,1153 @@
+/*
+ * 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"
+
+#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 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 struct strategy all_strategy[] = {
+ { "recur", NO_TRIVIAL },
+ { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
+ { "octopus", DEFAULT_OCTOPUS },
+ { "resolve", 0 },
+ { "stupid", 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 {
+ strbuf_addf(buf, "%s\n\n", arg);
+ have_message = 1;
+ }
+ return 0;
+}
+
+static int strategy_lookup(const char *path)
+{
+ int i;
+
+ if (!path)
+ return -1;
+
+ for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
+ if (!strcmp(path, all_strategy[i].name))
+ return all_strategy[i].attr;
+ return -1;
+}
+
+static inline void append_strategy(const char *name, unsigned attr)
+{
+ ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
+ use_strategies[use_strategies_nr].name = name;
+ use_strategies[use_strategies_nr++].attr = attr;
+}
+
+static int option_parse_strategy(const struct option *opt,
+ const char *arg, int unset)
+{
+ int i, attr;
+
+ if (unset)
+ return 0;
+
+ attr = strategy_lookup(arg);
+
+ if (attr >= 0)
+ append_strategy(arg, attr);
+ else {
+ struct strbuf err;
+ strbuf_init(&err, 0);
+ for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
+ strbuf_addf(&err, " %s", all_strategy[i].name);
+ fprintf(stderr, "Could not find merge strategy '%s'.\n", arg);
+ fprintf(stderr, "Available strategies are:%s.\n", err.buf);
+ exit(1);
+ }
+ 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_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_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"));
+}
+
+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;
+ const char *args[] = { "stash", "apply", NULL, NULL };
+
+ if (is_null_sha1(stash))
+ return;
+
+ reset_hard(head, 1);
+
+ strbuf_init(&sb, 0);
+ 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)
+{
+ 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;
+ struct commit_list *j;
+ int fd;
+
+ printf("Squash commit -- not updating HEAD\n");
+ fd = open(git_path("SQUASH_MSG"), O_WRONLY | O_CREAT, 0666);
+ if (fd < 0)
+ die("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");
+
+ strbuf_init(&out, 0);
+ 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, rev.abbrev,
+ NULL, NULL, rev.date_mode, 0);
+ }
+ write(fd, out.buf, out.len);
+ close(fd);
+ strbuf_release(&out);
+}
+
+static int run_hook(const char *name)
+{
+ struct child_process hook;
+ const char *argv[3], *env[2];
+ char index[PATH_MAX];
+
+ argv[0] = git_path("hooks/%s", name);
+ if (access(argv[0], X_OK) < 0)
+ return 0;
+
+ snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", get_index_file());
+ env[0] = index;
+ env[1] = NULL;
+
+ if (squash)
+ argv[1] = "1";
+ else
+ argv[1] = "0";
+ argv[2] = NULL;
+
+ memset(&hook, 0, sizeof(hook));
+ hook.argv = argv;
+ hook.no_stdin = 1;
+ hook.stdout_to_stderr = 1;
+ hook.env = env;
+
+ return run_command(&hook);
+}
+
+static void finish(const unsigned char *new_head, const char *msg)
+{
+ struct strbuf reflog_message;
+
+ strbuf_init(&reflog_message, 0);
+ if (!msg)
+ strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
+ else {
+ printf("%s\n", msg);
+ strbuf_addf(&reflog_message, "%s: %s",
+ getenv("GIT_REFLOG_ACTION"), msg);
+ }
+ if (squash) {
+ squash_message();
+ } else {
+ if (!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("post-merge");
+
+ 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;
+ const char *ptr;
+ int len, early;
+
+ 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);
+
+ strbuf_init(&buf, 0);
+ strbuf_addstr(&buf, "refs/heads/");
+ strbuf_addstr(&buf, remote);
+ resolve_ref(buf.buf, branch_head, 0, 0);
+
+ if (!hashcmp(remote_head->sha1, branch_head)) {
+ strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
+ sha1_to_hex(branch_head), remote);
+ return;
+ }
+
+ /* 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, len+11);
+ if (resolve_ref(truname.buf, buf_sha, 0, 0)) {
+ strbuf_addf(msg,
+ "%s\t\tbranch '%s'%s of .\n",
+ sha1_to_hex(remote_head->sha1),
+ truname.buf,
+ (early ? " (early part)" : ""));
+ return;
+ }
+ }
+
+ if (!strcmp(remote, "FETCH_HEAD") &&
+ !access(git_path("FETCH_HEAD"), R_OK)) {
+ FILE *fp;
+ struct strbuf line;
+ char *ptr;
+
+ strbuf_init(&line, 0);
+ fp = fopen(git_path("FETCH_HEAD"), "r");
+ if (!fp)
+ die("could not open %s for reading: %s",
+ git_path("FETCH_HEAD"), strerror(errno));
+ 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);
+ return;
+ }
+ strbuf_addf(msg, "%s\t\tcommit '%s'\n",
+ sha1_to_hex(remote_head->sha1), remote);
+}
+
+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);
+ argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
+ memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
+ argc++;
+ parse_options(argc, argv, 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);
+ 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;
+
+ args = xmalloc((4 + commit_list_count(common) +
+ commit_list_count(remoteheads)) * sizeof(char *));
+ strbuf_init(&buf, 0);
+ 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);
+ 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));
+
+ if (read_cache_unmerged())
+ die("you need to resolve your current index first");
+
+ fd = hold_locked_index(lock_file, 1);
+
+ memset(&trees, 0, sizeof(trees));
+ memset(&opts, 0, sizeof(opts));
+ memset(&t, 0, sizeof(t));
+ dir.show_ignored = 1;
+ 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;
+
+ 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 != NULL) {
+ for (i = 0; i < list_nr; i++) {
+ int attr;
+
+ attr = strategy_lookup(list[i].name);
+ if (attr >= 0)
+ append_strategy(list[i].name, attr);
+ }
+ return;
+ }
+ for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
+ if (all_strategy[i].attr & attr)
+ append_strategy(all_strategy[i].name,
+ all_strategy[i].attr);
+}
+
+static int merge_trivial(void)
+{
+ unsigned char result_tree[20], result_commit[20];
+ struct commit_list parent;
+
+ write_tree_trivial(result_tree);
+ printf("Wonderful.\n");
+ parent.item = remoteheads->item;
+ parent.next = NULL;
+ commit_tree(merge_msg.buf, result_tree, &parent, result_commit);
+ 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);
+ 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("Could 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 > 1) {
+ 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;
+
+ if (read_cache() < 0)
+ die("failed to read the cache");
+
+ /* 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;
+ 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;
+
+ setup_work_tree();
+ if (unmerged_cache())
+ die("You are in the middle of a conflicted merge.");
+
+ /*
+ * 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, builtin_merge_options,
+ builtin_merge_usage, 0);
+
+ if (squash) {
+ if (!allow_fast_forward)
+ die("You cannot combine --squash with --no-ff.");
+ option_commit = 0;
+ }
+
+ 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.
+ */
+ strbuf_init(&buf, 0);
+
+ 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");
+ 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;
+
+ /* 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.
+ */
+ strbuf_init(&msg, 0);
+ 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;
+
+ o = peel_to_type(argv[i], 0, NULL, OBJ_COMMIT);
+ if (!o)
+ die("%s - not something we can merge", argv[i]);
+ remotes = &commit_list_insert(lookup_commit(o->sha1),
+ 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);
+
+ if (!common)
+ ; /* No common ancestors found. We need a real merge. */
+ else if (!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.");
+ return 0;
+ } else if (allow_fast_forward && !remoteheads->next &&
+ !common->next &&
+ !hashcmp(common->item->object.sha1, head)) {
+ /* Again the most common case of merging one remote. */
+ struct strbuf msg;
+ struct object *o;
+ char hex[41];
+
+ strcpy(hex, find_unique_abbrev(head, DEFAULT_ABBREV));
+
+ printf("Updating %s..%s\n",
+ hex,
+ find_unique_abbrev(remoteheads->item->object.sha1,
+ DEFAULT_ABBREV));
+ refresh_cache(REFRESH_QUIET);
+ strbuf_init(&msg, 0);
+ strbuf_addstr(&msg, "Fast forward");
+ if (have_message)
+ strbuf_addstr(&msg,
+ " (no commit created; -m option ignored)");
+ o = peel_to_type(sha1_to_hex(remoteheads->item->object.sha1),
+ 0, NULL, OBJ_COMMIT);
+ if (!o)
+ return 1;
+
+ if (checkout_fast_forward(head, remoteheads->item->object.sha1))
+ return 1;
+
+ finish(o->sha1, msg.buf);
+ drop_save();
+ return 0;
+ } 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) {
+ /* See if it is really trivial. */
+ git_committer_info(IDENT_ERROR_ON_NO_NAME);
+ printf("Trying really trivial in-index merge...\n");
+ if (!read_tree_trivial(common->item->object.sha1,
+ head, remoteheads->item->object.sha1))
+ return merge_trivial();
+ 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(lookup_commit(head),
+ j->item, 1);
+ if (hashcmp(common_one->item->object.sha1,
+ j->item->object.sha1)) {
+ up_to_date = 0;
+ break;
+ }
+ }
+ if (up_to_date) {
+ finish_up_to_date("Already up-to-date. Yeeah!");
+ return 0;
+ }
+ }
+
+ /* We are going to make a new commit. */
+ git_committer_info(IDENT_ERROR_ON_NO_NAME);
+
+ /*
+ * 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();
+ } else {
+ memcpy(stash, null_sha1, 20);
+ }
+
+ for (i = 0; i < use_strategies_nr; i++) {
+ int ret;
+ if (i) {
+ printf("Rewinding the tree to pristine...\n");
+ restore_state();
+ }
+ 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, head_arg);
+ 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)
+ return finish_automerge(common, result_tree, wt_strategy);
+
+ /*
+ * Pick the result from the best strategy and have the user fix
+ * it up.
+ */
+ if (!best_strategy) {
+ restore_state();
+ 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);
+ return 2;
+ } 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();
+ printf("Using the %s to prepare resolving by hand.\n",
+ best_strategy);
+ try_merge_strategy(best_strategy, common, head_arg);
+ }
+
+ if (squash)
+ finish(NULL, NULL);
+ else {
+ int fd;
+ struct commit_list *j;
+
+ for (j = remoteheads; j; j = j->next)
+ strbuf_addf(&buf, "%s\n",
+ sha1_to_hex(j->item->object.sha1));
+ fd = open(git_path("MERGE_HEAD"), O_WRONLY | O_CREAT, 0666);
+ if (fd < 0)
+ die("Could open %s for writing",
+ git_path("MERGE_HEAD"));
+ if (write_in_full(fd, buf.buf, buf.len) != buf.len)
+ die("Could not write to %s", git_path("MERGE_HEAD"));
+ close(fd);
+ strbuf_addch(&merge_msg, '\n');
+ fd = open(git_path("MERGE_MSG"), O_WRONLY | O_CREAT, 0666);
+ if (fd < 0)
+ die("Could open %s for writing", git_path("MERGE_MSG"));
+ if (write_in_full(fd, merge_msg.buf, merge_msg.len) !=
+ merge_msg.len)
+ die("Could not write to %s", git_path("MERGE_MSG"));
+ close(fd);
+ }
+
+ if (merge_was_ok) {
+ fprintf(stderr, "Automatic merge went well; "
+ "stopped before committing as requested\n");
+ return 0;
+ } else
+ return suggest_conflicts();
+}