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-rw-r--r--builtin/merge.c1793
1 files changed, 1793 insertions, 0 deletions
diff --git a/builtin/merge.c b/builtin/merge.c
new file mode 100644
index 0000000..dd47437
--- /dev/null
+++ b/builtin/merge.c
@@ -0,0 +1,1793 @@
+/*
+ * Builtin "git merge"
+ *
+ * Copyright (c) 2008 Miklos Vajna <vmiklos@frugalware.org>
+ *
+ * Based on git-merge.sh by Junio C Hamano.
+ */
+
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
+#include "cache.h"
+#include "config.h"
+#include "parse-options.h"
+#include "builtin.h"
+#include "lockfile.h"
+#include "run-command.h"
+#include "hook.h"
+#include "diff.h"
+#include "diff-merges.h"
+#include "refs.h"
+#include "refspec.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 "merge-ort-wrappers.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"
+#include "tag.h"
+#include "alias.h"
+#include "branch.h"
+#include "commit-reach.h"
+#include "wt-status.h"
+#include "commit-graph.h"
+
+#define DEFAULT_TWOHEAD (1<<0)
+#define DEFAULT_OCTOPUS (1<<1)
+#define NO_FAST_FORWARD (1<<2)
+#define NO_TRIVIAL (1<<3)
+
+struct strategy {
+ const char *name;
+ unsigned attr;
+};
+
+static const char * const builtin_merge_usage[] = {
+ N_("git merge [<options>] [<commit>...]"),
+ "git merge --abort",
+ "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 check_trust_level = 1;
+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 verbosity;
+static int allow_rerere_auto;
+static int abort_current_merge;
+static int quit_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 autostash;
+static int no_verify;
+static char *into_name;
+
+static struct strategy all_strategy[] = {
+ { "recursive", NO_TRIVIAL },
+ { "octopus", DEFAULT_OCTOPUS },
+ { "ort", DEFAULT_TWOHEAD | NO_TRIVIAL },
+ { "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 const char *cleanup_arg;
+static enum commit_msg_cleanup_mode cleanup_mode;
+
+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 enum parse_opt_result option_read_message(struct parse_opt_ctx_t *ctx,
+ const struct option *opt,
+ const char *arg_not_used,
+ int unset)
+{
+ struct strbuf *buf = opt->value;
+ const char *arg;
+
+ BUG_ON_OPT_ARG(arg_not_used);
+ if (unset)
+ BUG("-F cannot be negated");
+
+ if (ctx->opt) {
+ arg = ctx->opt;
+ ctx->opt = NULL;
+ } else if (ctx->argc > 1) {
+ ctx->argc--;
+ arg = *++ctx->argv;
+ } else
+ return error(_("option `%s' requires a value"), opt->long_name);
+
+ if (buf->len)
+ strbuf_addch(buf, '\n');
+ if (ctx->prefix && !is_absolute_path(arg))
+ arg = prefix_filename(ctx->prefix, arg);
+ if (strbuf_read_file(buf, arg, 0) < 0)
+ return error(_("could not read file '%s'"), arg);
+ have_message = 1;
+
+ 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;
+ char *default_strategy = getenv("GIT_TEST_MERGE_ALGORITHM");
+
+ if (!name)
+ return NULL;
+
+ if (default_strategy &&
+ !strcmp(default_strategy, "ort") &&
+ !strcmp(name, "recursive")) {
+ name = "ort";
+ }
+
+ 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);
+ }
+
+ CALLOC_ARRAY(ret, 1);
+ 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)
+{
+ BUG_ON_OPT_ARG(arg);
+ show_diffstat = unset;
+ return 0;
+}
+
+static struct option builtin_merge_options[] = {
+ OPT_CALLBACK_F('n', NULL, NULL, NULL,
+ N_("do not show a diffstat at the end of the merge"),
+ PARSE_OPT_NOARG, option_parse_n),
+ OPT_BOOL(0, "stat", &show_diffstat,
+ N_("show a diffstat at the end of the merge")),
+ OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
+ { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
+ N_("add (at most <n>) entries from shortlog to merge commit message"),
+ PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
+ OPT_BOOL(0, "squash", &squash,
+ N_("create a single commit instead of doing a merge")),
+ OPT_BOOL(0, "commit", &option_commit,
+ N_("perform a commit if the merge succeeds (default)")),
+ OPT_BOOL('e', "edit", &option_edit,
+ N_("edit message before committing")),
+ OPT_CLEANUP(&cleanup_arg),
+ OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
+ OPT_SET_INT_F(0, "ff-only", &fast_forward,
+ N_("abort if fast-forward is not possible"),
+ FF_ONLY, PARSE_OPT_NONEG),
+ 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),
+ { OPTION_LOWLEVEL_CALLBACK, 'F', "file", &merge_msg, N_("path"),
+ N_("read message from file"), PARSE_OPT_NONEG,
+ NULL, 0, option_read_message },
+ OPT_STRING(0, "into-name", &into_name, N_("name"),
+ N_("use <name> instead of the real target")),
+ OPT__VERBOSITY(&verbosity),
+ OPT_BOOL(0, "abort", &abort_current_merge,
+ N_("abort the current in-progress merge")),
+ OPT_BOOL(0, "quit", &quit_current_merge,
+ N_("--abort but leave index and working tree alone")),
+ 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_AUTOSTASH(&autostash),
+ OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
+ OPT_BOOL(0, "signoff", &signoff, N_("add a Signed-off-by trailer")),
+ OPT_BOOL(0, "no-verify", &no_verify, N_("bypass pre-merge-commit and commit-msg hooks")),
+ OPT_END()
+};
+
+static int save_state(struct object_id *stash)
+{
+ int len;
+ struct child_process cp = CHILD_PROCESS_INIT;
+ struct strbuf buffer = STRBUF_INIT;
+ struct lock_file lock_file = LOCK_INIT;
+ int fd;
+ int rc = -1;
+
+ fd = repo_hold_locked_index(the_repository, &lock_file, 0);
+ refresh_index(&the_index, REFRESH_QUIET, NULL, NULL, NULL);
+ if (0 <= fd)
+ repo_update_index_if_able(the_repository, &lock_file);
+ rollback_lock_file(&lock_file);
+
+ strvec_pushl(&cp.args, "stash", "create", NULL);
+ 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(const struct object_id *oid)
+{
+ struct child_process cmd = CHILD_PROCESS_INIT;
+
+ strvec_pushl(&cmd.args, "read-tree", "-m", "-u", empty_tree_oid_hex(),
+ oid_to_hex(oid), NULL);
+ cmd.git_cmd = 1;
+
+ if (run_command(&cmd))
+ die(_("read-tree failed"));
+}
+
+static void reset_hard(const struct object_id *oid)
+{
+ struct child_process cmd = CHILD_PROCESS_INIT;
+
+ strvec_pushl(&cmd.args, "read-tree", "-v", "--reset", "-u",
+ oid_to_hex(oid), NULL);
+ cmd.git_cmd = 1;
+
+ if (run_command(&cmd))
+ die(_("read-tree failed"));
+}
+
+static void restore_state(const struct object_id *head,
+ const struct object_id *stash)
+{
+ struct child_process cmd = CHILD_PROCESS_INIT;
+
+ reset_hard(head);
+
+ if (is_null_oid(stash))
+ goto refresh_cache;
+
+ strvec_pushl(&cmd.args, "stash", "apply", "--index", "--quiet", NULL);
+ strvec_push(&cmd.args, oid_to_hex(stash));
+
+ /*
+ * It is OK to ignore error here, for example when there was
+ * nothing to restore.
+ */
+ cmd.git_cmd = 1;
+ run_command(&cmd);
+
+refresh_cache:
+ discard_cache();
+ if (read_cache() < 0)
+ die(_("could not read index"));
+}
+
+/* This is called when no merge was necessary. */
+static void finish_up_to_date(void)
+{
+ if (verbosity >= 0) {
+ if (squash)
+ puts(_("Already up to date. (nothing to squash)"));
+ else
+ puts(_("Already up to date."));
+ }
+ remove_merge_branch_state(the_repository);
+}
+
+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"));
+
+ repo_init_revisions(the_repository, &rev, NULL);
+ diff_merges_suppress(&rev);
+ 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(the_repository), out.buf, out.len);
+ strbuf_release(&out);
+ release_revisions(&rev);
+}
+
+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 {
+ 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.
+ */
+ run_auto_maintenance(verbosity < 0);
+ }
+ }
+ if (new_head && show_diffstat) {
+ struct diff_options opts;
+ repo_diff_setup(the_repository, &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_hooks_l("post-merge", squash ? "1" : "0", NULL);
+
+ if (new_head)
+ apply_autostash(git_path_merge_autostash(the_repository));
+ 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 bname = STRBUF_INIT;
+ struct merge_remote_desc *desc;
+ const char *ptr;
+ char *found_ref = NULL;
+ 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) > 0) {
+ if (starts_with(found_ref, "refs/heads/")) {
+ strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
+ oid_to_hex(&branch_head), remote);
+ goto cleanup;
+ }
+ if (starts_with(found_ref, "refs/tags/")) {
+ strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
+ oid_to_hex(&branch_head), remote);
+ goto cleanup;
+ }
+ if (starts_with(found_ref, "refs/remotes/")) {
+ strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
+ oid_to_hex(&branch_head), remote);
+ goto cleanup;
+ }
+ }
+
+ /* See if remote matches <name>^^^.. or <name>~<number> */
+ for (len = 0, ptr = remote + strlen(remote);
+ remote < ptr && ptr[-1] == '^';
+ ptr--)
+ len++;
+ if (len)
+ early = 1;
+ else {
+ early = 0;
+ ptr = strrchr(remote, '~');
+ if (ptr) {
+ int seen_nonzero = 0;
+
+ len++; /* count ~ */
+ while (*++ptr && isdigit(*ptr)) {
+ seen_nonzero |= (*ptr != '0');
+ len++;
+ }
+ if (*ptr)
+ len = 0; /* not ...~<number> */
+ else if (seen_nonzero)
+ early = 1;
+ else if (len == 1)
+ early = 1; /* "name~" is "name~1"! */
+ }
+ }
+ if (len) {
+ struct strbuf truname = STRBUF_INIT;
+ strbuf_addf(&truname, "refs/heads/%s", remote);
+ strbuf_setlen(&truname, truname.len - len);
+ if (ref_exists(truname.buf)) {
+ strbuf_addf(msg,
+ "%s\t\tbranch '%s'%s of .\n",
+ oid_to_hex(&remote_head->object.oid),
+ truname.buf + 11,
+ (early ? " (early part)" : ""));
+ strbuf_release(&truname);
+ goto cleanup;
+ }
+ strbuf_release(&truname);
+ }
+
+ 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),
+ type_name(desc->obj->type),
+ remote);
+ goto cleanup;
+ }
+
+ strbuf_addf(msg, "%s\t\tcommit '%s'\n",
+ oid_to_hex(&remote_head->object.oid), remote);
+cleanup:
+ free(found_ref);
+ 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;
+ const char *str;
+
+ if (branch &&
+ skip_prefix(k, "branch.", &str) &&
+ skip_prefix(str, branch, &str) &&
+ !strcmp(str, ".mergeoptions")) {
+ free(branch_mergeoptions);
+ branch_mergeoptions = xstrdup(v);
+ return 0;
+ }
+
+ if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
+ show_diffstat = git_config_bool(k, v);
+ else if (!strcmp(k, "merge.verifysignatures"))
+ verify_signatures = git_config_bool(k, v);
+ else if (!strcmp(k, "pull.twohead"))
+ return git_config_string(&pull_twohead, k, v);
+ else if (!strcmp(k, "pull.octopus"))
+ return git_config_string(&pull_octopus, k, v);
+ else if (!strcmp(k, "commit.cleanup"))
+ return git_config_string(&cleanup_arg, 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;
+ } else if (!strcmp(k, "gpg.mintrustlevel")) {
+ check_trust_level = 0;
+ } else if (!strcmp(k, "merge.autostash")) {
+ autostash = git_config_bool(k, v);
+ 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;
+ opts.preserve_ignored = 0; /* FIXME: !overwrite_ignore */
+ 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(&the_index.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, 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)
+{
+ const char *head_arg = "HEAD";
+
+ if (repo_refresh_and_write_index(the_repository, REFRESH_QUIET,
+ SKIP_IF_UNCHANGED, 0, NULL, NULL,
+ NULL) < 0)
+ return error(_("Unable to write index."));
+
+ if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree") ||
+ !strcmp(strategy, "ort")) {
+ struct lock_file lock = LOCK_INIT;
+ 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, the_repository);
+ if (!strcmp(strategy, "subtree"))
+ o.subtree_shift = "";
+
+ 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 strategy option: -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);
+
+ repo_hold_locked_index(the_repository, &lock,
+ LOCK_DIE_ON_ERROR);
+ if (!strcmp(strategy, "ort"))
+ clean = merge_ort_recursive(&o, head, remoteheads->item,
+ reversed, &result);
+ else
+ clean = merge_recursive(&o, head, remoteheads->item,
+ reversed, &result);
+ if (clean < 0) {
+ rollback_lock_file(&lock);
+ return 2;
+ }
+ if (write_locked_index(&the_index, &lock,
+ COMMIT_LOCK | SKIP_IF_UNCHANGED))
+ die(_("unable to write %s"), get_index_file());
+ return clean ? 0 : 1;
+ } else {
+ return try_merge_command(the_repository,
+ 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 < the_index.cache_nr; i++)
+ if (ce_stage(the_index.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(the_repository);
+ 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");
+
+static const char scissors_editor_comment[] =
+N_("An empty message aborts the commit.\n");
+
+static const char no_scissors_editor_comment[] =
+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;
+ const char *index_file = get_index_file();
+
+ if (!no_verify) {
+ int invoked_hook;
+
+ if (run_commit_hook(0 < option_edit, index_file, &invoked_hook,
+ "pre-merge-commit", NULL))
+ abort_commit(remoteheads, NULL);
+ /*
+ * Re-read the index as pre-merge-commit hook could have updated it,
+ * and write it out as a tree. We must do this before we invoke
+ * the editor and after we invoke run_status above.
+ */
+ if (invoked_hook)
+ discard_index(&the_index);
+ }
+ read_index_from(&the_index, index_file, get_git_dir());
+ strbuf_addbuf(&msg, &merge_msg);
+ if (squash)
+ BUG("the control must not reach here under --squash");
+ if (0 < option_edit) {
+ strbuf_addch(&msg, '\n');
+ if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS) {
+ wt_status_append_cut_line(&msg);
+ strbuf_commented_addf(&msg, "\n");
+ }
+ strbuf_commented_addf(&msg, _(merge_editor_comment));
+ if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS)
+ strbuf_commented_addf(&msg, _(scissors_editor_comment));
+ else
+ strbuf_commented_addf(&msg,
+ _(no_scissors_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(the_repository), msg.buf, msg.len);
+ if (run_commit_hook(0 < option_edit, get_index_file(), NULL,
+ "prepare-commit-msg",
+ git_path_merge_msg(the_repository), "merge", NULL))
+ abort_commit(remoteheads, NULL);
+ if (0 < option_edit) {
+ if (launch_editor(git_path_merge_msg(the_repository), NULL, NULL))
+ abort_commit(remoteheads, NULL);
+ }
+
+ if (!no_verify && run_commit_hook(0 < option_edit, get_index_file(),
+ NULL, "commit-msg",
+ git_path_merge_msg(the_repository), NULL))
+ abort_commit(remoteheads, NULL);
+
+ read_merge_msg(&msg);
+ cleanup_message(&msg, cleanup_mode, 0);
+ 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;
+
+ if (repo_refresh_and_write_index(the_repository, REFRESH_QUIET,
+ SKIP_IF_UNCHANGED, 0, NULL, NULL,
+ NULL) < 0)
+ return error(_("Unable to write index."));
+
+ write_tree_trivial(&result_tree);
+ printf(_("Wonderful.\n"));
+ pptr = commit_list_append(head, pptr);
+ pptr = commit_list_append(remoteheads->item, pptr);
+ prepare_to_commit(remoteheads);
+ if (commit_tree(merge_msg.buf, merge_msg.len, &result_tree, parents,
+ &result_commit, NULL, sign_commit))
+ die(_("failed to write commit object"));
+ finish(head, remoteheads, &result_commit, "In-index merge");
+ remove_merge_branch_state(the_repository);
+ 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;
+
+ write_tree_trivial(result_tree);
+ free_commit_list(common);
+ parents = remoteheads;
+ if (!head_subsumed || fast_forward == FF_NO)
+ commit_list_insert(head, &parents);
+ prepare_to_commit(remoteheads);
+ if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
+ &result_commit, NULL, sign_commit))
+ die(_("failed to write commit object"));
+ strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
+ finish(head, remoteheads, &result_commit, buf.buf);
+ strbuf_release(&buf);
+ remove_merge_branch_state(the_repository);
+ return 0;
+}
+
+static int suggest_conflicts(void)
+{
+ const char *filename;
+ FILE *fp;
+ struct strbuf msgbuf = STRBUF_INIT;
+
+ filename = git_path_merge_msg(the_repository);
+ fp = xfopen(filename, "a");
+
+ /*
+ * We can't use cleanup_mode because if we're not using the editor,
+ * get_cleanup_mode will return COMMIT_MSG_CLEANUP_SPACE instead, even
+ * though the message is meant to be processed later by git-commit.
+ * Thus, we will get the cleanup mode which is returned when we _are_
+ * using an editor.
+ */
+ append_conflicts_hint(&the_index, &msgbuf,
+ get_cleanup_mode(cleanup_arg, 1));
+ fputs(msgbuf.buf, fp);
+ strbuf_release(&msgbuf);
+ fclose(fp);
+ repo_rerere(the_repository, 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. */
+ repo_init_revisions(the_repository, &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();
+
+ release_revisions(&rev);
+ 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;
+ struct merge_remote_desc *desc;
+
+ desc = merge_remote_util(c);
+ if (desc && desc->obj) {
+ oid = &desc->obj->oid;
+ } else {
+ oid = &c->object.oid;
+ }
+ strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
+ }
+ write_file_buf(git_path_merge_head(the_repository), buf.buf, buf.len);
+
+ strbuf_reset(&buf);
+ if (fast_forward == FF_NO)
+ strbuf_addstr(&buf, "no-ff");
+ write_file_buf(git_path_merge_mode(the_repository), 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(the_repository), 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);
+ opts.into_name = into_name;
+
+ 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;
+ const unsigned hexsz = the_hash_algo->hexsz;
+
+ if (!merge_names)
+ merge_names = &fetch_head_file;
+
+ filename = git_path_fetch_head(the_repository);
+ fd = xopen(filename, O_RDONLY);
+
+ 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 < hexsz + 2 ||
+ get_oid_hex(merge_names->buf + pos, &oid))
+ commit = NULL; /* bad */
+ else if (memcmp(merge_names->buf + pos + hexsz, "\t\t", 2))
+ continue; /* not-for-merge */
+ else {
+ char saved = merge_names->buf[pos + hexsz];
+ merge_names->buf[pos + hexsz] = '\0';
+ commit = get_merge_parent(merge_names->buf + pos);
+ merge_names->buf[pos + 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;
+}
+
+static int merging_a_throwaway_tag(struct commit *commit)
+{
+ char *tag_ref;
+ struct object_id oid;
+ int is_throwaway_tag = 0;
+
+ /* Are we merging a tag? */
+ if (!merge_remote_util(commit) ||
+ !merge_remote_util(commit)->obj ||
+ merge_remote_util(commit)->obj->type != OBJ_TAG)
+ return is_throwaway_tag;
+
+ /*
+ * Now we know we are merging a tag object. Are we downstream
+ * and following the tags from upstream? If so, we must have
+ * the tag object pointed at by "refs/tags/$T" where $T is the
+ * tagname recorded in the tag object. We want to allow such
+ * a "just to catch up" merge to fast-forward.
+ *
+ * Otherwise, we are playing an integrator's role, making a
+ * merge with a throw-away tag from a contributor with
+ * something like "git pull $contributor $signed_tag".
+ * We want to forbid such a merge from fast-forwarding
+ * by default; otherwise we would not keep the signature
+ * anywhere.
+ */
+ tag_ref = xstrfmt("refs/tags/%s",
+ ((struct tag *)merge_remote_util(commit)->obj)->tag);
+ if (!read_ref(tag_ref, &oid) &&
+ oideq(&oid, &merge_remote_util(commit)->obj->oid))
+ is_throwaway_tag = 0;
+ else
+ is_throwaway_tag = 1;
+ free(tag_ref);
+ return is_throwaway_tag;
+}
+
+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 = NULL, *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);
+
+ prepare_repo_settings(the_repository);
+ the_repository->settings.command_requires_full_index = 0;
+
+ /*
+ * 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 (!pull_twohead) {
+ char *default_strategy = getenv("GIT_TEST_MERGE_ALGORITHM");
+ if (default_strategy && !strcmp(default_strategy, "ort"))
+ pull_twohead = "ort";
+ }
+
+ init_diff_ui_defaults();
+ git_config(git_merge_config, NULL);
+
+ if (!branch || is_null_oid(&head_oid))
+ head_commit = NULL;
+ else
+ head_commit = lookup_commit_or_die(&head_oid, "HEAD");
+
+ 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};
+ struct strbuf stash_oid = STRBUF_INIT;
+
+ if (orig_argc != 2)
+ usage_msg_opt(_("--abort expects no arguments"),
+ builtin_merge_usage, builtin_merge_options);
+
+ if (!file_exists(git_path_merge_head(the_repository)))
+ die(_("There is no merge to abort (MERGE_HEAD missing)."));
+
+ if (read_oneliner(&stash_oid, git_path_merge_autostash(the_repository),
+ READ_ONELINER_SKIP_IF_EMPTY))
+ unlink(git_path_merge_autostash(the_repository));
+
+ /* Invoke 'git reset --merge' */
+ ret = cmd_reset(nargc, nargv, prefix);
+
+ if (stash_oid.len)
+ apply_autostash_oid(stash_oid.buf);
+
+ strbuf_release(&stash_oid);
+ goto done;
+ }
+
+ if (quit_current_merge) {
+ if (orig_argc != 2)
+ usage_msg_opt(_("--quit expects no arguments"),
+ builtin_merge_usage,
+ builtin_merge_options);
+
+ remove_merge_branch_state(the_repository);
+ 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(the_repository)))
+ die(_("There is no merge in progress (MERGE_HEAD missing)."));
+
+ /* Invoke 'git commit' */
+ ret = cmd_commit(nargc, nargv, prefix);
+ goto done;
+ }
+
+ if (repo_read_index_unmerged(the_repository))
+ die_resolve_conflict("merge");
+
+ if (file_exists(git_path_merge_head(the_repository))) {
+ /*
+ * There is no unmerged entry, don't advise 'git
+ * add/rm <file>', just 'git commit'.
+ */
+ if (advice_enabled(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 (ref_exists("CHERRY_PICK_HEAD")) {
+ if (advice_enabled(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_index(&the_index);
+
+ if (option_edit < 0)
+ option_edit = default_edit_option();
+
+ cleanup_mode = get_cleanup_mode(cleanup_arg, 0 < option_edit);
+
+ if (verbosity < 0)
+ show_diffstat = 0;
+
+ if (squash) {
+ if (fast_forward == FF_NO)
+ die(_("options '%s' and '%s' cannot be used together"), "--squash", "--no-ff.");
+ if (option_commit > 0)
+ die(_("options '%s' and '%s' cannot be used together"), "--squash", "--commit.");
+ /*
+ * squash can now silently disable option_commit - this is not
+ * a problem as it is only overriding the default, not a user
+ * supplied option.
+ */
+ option_commit = 0;
+ }
+
+ if (option_commit < 0)
+ option_commit = 1;
+
+ 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"));
+
+ if (verify_signatures)
+ verify_merge_signature(remoteheads->item, verbosity,
+ check_trust_level);
+
+ remote_head_oid = &remoteheads->item->object.oid;
+ read_empty(remote_head_oid);
+ 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) {
+ verify_merge_signature(p->item, verbosity,
+ check_trust_level);
+ }
+ }
+
+ 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 && merging_a_throwaway_tag(commit))
+ fast_forward = FF_NO;
+ }
+
+ if (!use_strategies && !pull_twohead &&
+ remoteheads && !remoteheads->next) {
+ char *default_strategy = getenv("GIT_TEST_MERGE_ALGORITHM");
+ if (default_strategy)
+ append_strategy(get_strategy(default_strategy));
+ }
+ 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();
+ goto done;
+ } else if (fast_forward != FF_NO && !remoteheads->next &&
+ !common->next &&
+ oideq(&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,
+ DEFAULT_ABBREV),
+ find_unique_abbrev(&remoteheads->item->object.oid,
+ 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 (autostash)
+ create_autostash(the_repository,
+ git_path_merge_autostash(the_repository));
+ if (checkout_fast_forward(the_repository,
+ &head_commit->object.oid,
+ &commit->object.oid,
+ overwrite_ignore)) {
+ apply_autostash(git_path_merge_autostash(the_repository));
+ ret = 1;
+ goto done;
+ }
+
+ finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
+ remove_merge_branch_state(the_repository);
+ strbuf_release(&msg);
+ 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_index(&the_index, REFRESH_QUIET, NULL, NULL, NULL);
+ if (allow_trivial && fast_forward != FF_ONLY) {
+ /*
+ * Must first ensure that index matches HEAD before
+ * attempting a trivial merge.
+ */
+ struct tree *head_tree = get_commit_tree(head_commit);
+ struct strbuf sb = STRBUF_INIT;
+
+ if (repo_index_has_changes(the_repository, head_tree,
+ &sb)) {
+ error(_("Your local changes to the following files would be overwritten by merge:\n %s"),
+ sb.buf);
+ strbuf_release(&sb);
+ return 2;
+ }
+
+ /* 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 (!oideq(&common_one->item->object.oid, &j->item->object.oid)) {
+ up_to_date = 0;
+ break;
+ }
+ }
+ if (up_to_date) {
+ finish_up_to_date();
+ goto done;
+ }
+ }
+
+ if (fast_forward == FF_ONLY)
+ die_ff_impossible();
+
+ if (autostash)
+ create_autostash(the_repository,
+ git_path_merge_autostash(the_repository));
+
+ /* 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.
+ *
+ * Stash away the local changes so that we can try more than one
+ * and/or recover from merge strategies bailing while leaving the
+ * index and working tree polluted.
+ */
+ if (save_state(&stash))
+ oidclr(&stash);
+
+ for (i = 0; i < use_strategies_nr; i++) {
+ int ret, cnt;
+ 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(wt_strategy,
+ common, remoteheads,
+ head_commit);
+ /*
+ * 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 < 2) {
+ if (!ret) {
+ /*
+ * This strategy worked; no point in trying
+ * another.
+ */
+ merge_was_ok = 1;
+ best_strategy = wt_strategy;
+ break;
+ }
+ cnt = (use_strategies_nr > 1) ? evaluate_result() : 0;
+ if (best_cnt <= 0 || cnt <= best_cnt) {
+ best_strategy = wt_strategy;
+ best_cnt = cnt;
+ }
+ }
+ }
+
+ /*
+ * If we have a resulting tree, that means the strategy module
+ * auto resolved the merge cleanly.
+ */
+ if (merge_was_ok && option_commit) {
+ automerge_was_ok = 1;
+ 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);
+ apply_autostash(git_path_merge_autostash(the_repository));
+ 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 strategy 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);
+
+ git_test_write_commit_graph_or_die();
+ } 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();
+ if (autostash)
+ printf(_("When finished, apply stashed changes with `git stash pop`\n"));
+
+done:
+ if (!automerge_was_ok) {
+ free_commit_list(common);
+ free_commit_list(remoteheads);
+ }
+ strbuf_release(&buf);
+ free(branch_to_free);
+ return ret;
+}