Code

Merge branch 'jc/maint-branch-mergeoptions' into mg/merge-ff-config
authorJunio C Hamano <gitster@pobox.com>
Fri, 6 May 2011 22:03:25 +0000 (15:03 -0700)
committerJunio C Hamano <gitster@pobox.com>
Fri, 6 May 2011 22:10:36 +0000 (15:10 -0700)
* jc/maint-branch-mergeoptions:
  merge: make branch.<name>.mergeoptions correctly override merge.<option>

1  2 
builtin/merge.c
t/t7600-merge.sh

diff --cc builtin/merge.c
index d54e7ddbb12286beb4f9622864f2eeaa79453d32,0000000000000000000000000000000000000000..0f03dff1160f68de6f406f038c1b5c2bbd6529c8
mode 100644,000000..100644
--- /dev/null
@@@ -1,1420 -1,0 +1,1431 @@@
-               const char **argv;
-               int argc;
-               char *buf;
-               buf = xstrdup(v);
-               argc = split_cmdline(buf, &argv);
-               if (argc < 0)
-                       die(_("Bad branch.%s.mergeoptions string: %s"), branch,
-                           split_cmdline_strerror(argc));
-               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);
 +/*
 + * 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"
 +#include "resolve-undo.h"
 +#include "remote.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] [<commit>...]",
 +      "git merge [options] <msg> HEAD <commit>",
 +      "git merge --abort",
 +      NULL
 +};
 +
 +static int show_diffstat = 1, shortlog_len, 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 **xopts;
 +static size_t xopts_nr, xopts_alloc;
 +static const char *branch;
++static char *branch_mergeoptions;
 +static int option_renormalize;
 +static int verbosity;
 +static int allow_rerere_auto;
 +static int abort_current_merge;
 +static int show_progress = -1;
 +static int default_to_upstream;
 +
 +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);
 +      ret->attr = NO_TRIVIAL;
 +      return ret;
 +}
 +
 +static void append_strategy(struct strategy *s)
 +{
 +      ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
 +      use_strategies[use_strategies_nr++] = s;
 +}
 +
 +static int option_parse_strategy(const struct option *opt,
 +                               const char *name, int unset)
 +{
 +      if (unset)
 +              return 0;
 +
 +      append_strategy(get_strategy(name));
 +      return 0;
 +}
 +
 +static int option_parse_x(const struct option *opt,
 +                        const char *arg, int unset)
 +{
 +      if (unset)
 +              return 0;
 +
 +      ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
 +      xopts[xopts_nr++] = xstrdup(arg);
 +      return 0;
 +}
 +
 +static int option_parse_n(const struct option *opt,
 +                        const char *arg, int unset)
 +{
 +      show_diffstat = unset;
 +      return 0;
 +}
 +
 +static struct option builtin_merge_options[] = {
 +      { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
 +              "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)"),
 +      { OPTION_INTEGER, 0, "log", &shortlog_len, "n",
 +        "add (at most <n>) entries from shortlog to merge commit message",
 +        PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
 +      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_RERERE_AUTOUPDATE(&allow_rerere_auto),
 +      OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",
 +              "merge strategy to use", option_parse_strategy),
 +      OPT_CALLBACK('X', "strategy-option", &xopts, "option=value",
 +              "option for selected merge strategy", option_parse_x),
 +      OPT_CALLBACK('m', "message", &merge_msg, "message",
 +              "merge commit message (for a non-fast-forward merge)",
 +              option_parse_message),
 +      OPT__VERBOSITY(&verbosity),
 +      OPT_BOOLEAN(0, "abort", &abort_current_merge,
 +              "abort the current in-progress merge"),
 +      OPT_SET_INT(0, "progress", &show_progress, "force progress reporting", 1),
 +      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 read_empty(unsigned const char *sha1, int verbose)
 +{
 +      int i = 0;
 +      const char *args[7];
 +
 +      args[i++] = "read-tree";
 +      if (verbose)
 +              args[i++] = "-v";
 +      args[i++] = "-m";
 +      args[i++] = "-u";
 +      args[i++] = EMPTY_TREE_SHA1_HEX;
 +      args[i++] = sha1_to_hex(sha1);
 +      args[i] = NULL;
 +
 +      if (run_command_v_opt(args, RUN_GIT_CMD))
 +              die(_("read-tree failed"));
 +}
 +
 +static void reset_hard(unsigned const char *sha1, int verbose)
 +{
 +      int i = 0;
 +      const char *args[6];
 +
 +      args[i++] = "read-tree";
 +      if (verbose)
 +              args[i++] = "-v";
 +      args[i++] = "--reset";
 +      args[i++] = "-u";
 +      args[i++] = sha1_to_hex(sha1);
 +      args[i] = NULL;
 +
 +      if (run_command_v_opt(args, RUN_GIT_CMD))
 +              die(_("read-tree failed"));
 +}
 +
 +static void restore_state(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-tracking 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, 1, 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 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));
++      argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
++      memmove(argv + 1, argv, sizeof(*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)
 +{
 +      if (branch && !prefixcmp(k, "branch.") &&
 +              !prefixcmp(k + 7, branch) &&
 +              !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
++              free(branch_mergeoptions);
++              branch_mergeoptions = xstrdup(v);
++              return 0;
 +      }
 +
 +      if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
 +              show_diffstat = git_config_bool(k, v);
 +      else if (!strcmp(k, "pull.twohead"))
 +              return git_config_string(&pull_twohead, k, v);
 +      else if (!strcmp(k, "pull.octopus"))
 +              return git_config_string(&pull_octopus, k, v);
 +      else if (!strcmp(k, "merge.renormalize"))
 +              option_renormalize = git_config_bool(k, v);
 +      else if (!strcmp(k, "merge.log") || !strcmp(k, "merge.summary")) {
 +              int is_bool;
 +              shortlog_len = git_config_bool_or_int(k, v, &is_bool);
 +              if (!is_bool && shortlog_len < 0)
 +                      return error(_("%s: negative length %s"), k, v);
 +              if (is_bool && shortlog_len)
 +                      shortlog_len = DEFAULT_MERGE_LOG_LEN;
 +              return 0;
 +      } else if (!strcmp(k, "merge.defaulttoupstream")) {
 +              default_to_upstream = git_config_bool(k, v);
 +              return 0;
 +      }
 +      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"));
 +}
 +
 +int try_merge_command(const char *strategy, size_t xopts_nr,
 +                    const char **xopts, struct commit_list *common,
 +                    const char *head_arg, struct commit_list *remotes)
 +{
 +      const char **args;
 +      int i = 0, x = 0, ret;
 +      struct commit_list *j;
 +      struct strbuf buf = STRBUF_INIT;
 +
 +      args = xmalloc((4 + xopts_nr + commit_list_count(common) +
 +                      commit_list_count(remotes)) * sizeof(char *));
 +      strbuf_addf(&buf, "merge-%s", strategy);
 +      args[i++] = buf.buf;
 +      for (x = 0; x < xopts_nr; x++) {
 +              char *s = xmalloc(strlen(xopts[x])+2+1);
 +              strcpy(s, "--");
 +              strcpy(s+2, xopts[x]);
 +              args[i++] = s;
 +      }
 +      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 = remotes; 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 (x = 0; x < xopts_nr; x++)
 +              free((void *)args[i++]);
 +      for (j = common; j; j = j->next)
 +              free((void *)args[i++]);
 +      i += 2;
 +      for (j = remotes; j; j = j->next)
 +              free((void *)args[i++]);
 +      free(args);
 +      discard_cache();
 +      if (read_cache() < 0)
 +              die(_("failed to read the cache"));
 +      resolve_undo_clear();
 +
 +      return ret;
 +}
 +
 +static int try_merge_strategy(const char *strategy, struct commit_list *common,
 +                            const char *head_arg)
 +{
 +      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, x;
 +              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;
 +              struct commit_list *j;
 +
 +              if (remoteheads->next) {
 +                      error(_("Not handling anything other than two heads merge."));
 +                      return 2;
 +              }
 +
 +              init_merge_options(&o);
 +              if (!strcmp(strategy, "subtree"))
 +                      o.subtree_shift = "";
 +
 +              o.renormalize = option_renormalize;
 +              o.show_rename_progress =
 +                      show_progress == -1 ? isatty(2) : show_progress;
 +
 +              for (x = 0; x < xopts_nr; x++)
 +                      if (parse_merge_opt(&o, xopts[x]))
 +                              die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
 +
 +              o.branch1 = head_arg;
 +              o.branch2 = 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 {
 +              return try_merge_command(strategy, xopts_nr, xopts,
 +                                              common, head_arg, remoteheads);
 +      }
 +}
 +
 +static void count_diff_files(struct diff_queue_struct *q,
 +                           struct diff_options *opt, void *data)
 +{
 +      int *count = data;
 +
 +      (*count) += q->nr;
 +}
 +
 +static int count_unmerged_entries(void)
 +{
 +      int i, ret = 0;
 +
 +      for (i = 0; i < active_nr; i++)
 +              if (ce_stage(active_cache[i]))
 +                      ret++;
 +
 +      return ret;
 +}
 +
 +int checkout_fast_forward(const unsigned char *head, const 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;
 +      setup_unpack_trees_porcelain(&opts, "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) {
 +              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 void write_merge_msg(void)
 +{
 +      int fd = open(git_path("MERGE_MSG"), O_WRONLY | O_CREAT, 0666);
 +      if (fd < 0)
 +              die_errno(_("Could not open '%s' for writing"),
 +                        git_path("MERGE_MSG"));
 +      if (write_in_full(fd, merge_msg.buf, merge_msg.len) != merge_msg.len)
 +              die_errno(_("Could not write to '%s'"), git_path("MERGE_MSG"));
 +      close(fd);
 +}
 +
 +static void read_merge_msg(void)
 +{
 +      strbuf_reset(&merge_msg);
 +      if (strbuf_read_file(&merge_msg, git_path("MERGE_MSG"), 0) < 0)
 +              die_errno("Could not read from '%s'", git_path("MERGE_MSG"));
 +}
 +
 +static void run_prepare_commit_msg(void)
 +{
 +      write_merge_msg();
 +      run_hook(get_index_file(), "prepare-commit-msg",
 +               git_path("MERGE_MSG"), "merge", NULL, NULL);
 +      read_merge_msg();
 +}
 +
 +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;
 +      run_prepare_commit_msg();
 +      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');
 +      run_prepare_commit_msg();
 +      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(int renormalizing)
 +{
 +      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(allow_rerere_auto);
 +      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;
 +}
 +
 +/*
 + * Pretend as if the user told us to merge with the 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)
 +              die("No remote for the current branch.");
 +      if (!branch->merge_nr)
 +              die("No default upstream defined for the current branch.");
 +
 +      args = xcalloc(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;
 +}
 +
 +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 (argc == 2 && !strcmp(argv[1], "-h"))
 +              usage_with_options(builtin_merge_usage, builtin_merge_options);
 +
 +      /*
 +       * Check if we are _not_ on a detached HEAD, i.e. if there is a
 +       * current branch.
 +       */
 +      branch = 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;
 +
++      if (branch_mergeoptions)
++              parse_branch_merge_options(branch_mergeoptions);
 +      argc = parse_options(argc, argv, prefix, builtin_merge_options,
 +                      builtin_merge_usage, 0);
 +
 +      if (verbosity < 0 && show_progress == -1)
 +              show_progress = 0;
 +
 +      if (abort_current_merge) {
 +              int nargc = 2;
 +              const char *nargv[] = {"reset", "--merge", NULL};
 +
 +              if (!file_exists(git_path("MERGE_HEAD")))
 +                      die(_("There is no merge to abort (MERGE_HEAD missing)."));
 +
 +              /* Invoke 'git reset --merge' */
 +              return cmd_reset(nargc, nargv, prefix);
 +      }
 +
 +      if (read_cache_unmerged())
 +              die_resolve_conflict("merge");
 +
 +      if (file_exists(git_path("MERGE_HEAD"))) {
 +              /*
 +               * There is no unmerged entry, don't advise 'git
 +               * add/rm <file>', just 'git commit'.
 +               */
 +              if (advice_resolve_conflict)
 +                      die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
 +                                "Please, commit your changes before you can merge."));
 +              else
 +                      die(_("You have not concluded your merge (MERGE_HEAD exists)."));
 +      }
 +      if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
 +              if (advice_resolve_conflict)
 +                      die("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
 +                          "Please, commit your changes before you can merge.");
 +              else
 +                      die("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).");
 +      }
 +      resolve_undo_clear();
 +
 +      if (verbosity < 0)
 +              show_diffstat = 0;
 +
 +      if (squash) {
 +              if (!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 && !abort_current_merge && default_to_upstream)
 +              argc = setup_with_upstream(&argv);
 +
 +      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]);
 +              read_empty(remote_head->sha1, 0);
 +              update_ref("initial pull", "HEAD", remote_head->sha1, NULL, 0,
 +                              DIE_ON_ERR);
 +              return 0;
 +      } else {
 +              struct strbuf merge_names = 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.
 +               */
 +              for (i = 0; i < argc; i++)
 +                      merge_name(argv[i], &merge_names);
 +
 +              if (!have_message || shortlog_len) {
 +                      fmt_merge_msg(&merge_names, &merge_msg, !have_message,
 +                                    shortlog_len);
 +                      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);
 +
 +      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 = STRBUF_INIT;
 +              struct object *o;
 +              char hex[41];
 +
 +              strcpy(hex, find_unique_abbrev(head, DEFAULT_ABBREV));
 +
 +              if (verbosity >= 0)
 +                      printf(_("Updating %s..%s\n"),
 +                              hex,
 +                              find_unique_abbrev(remoteheads->item->object.sha1,
 +                              DEFAULT_ABBREV));
 +              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 && !fast_forward_only) {
 +                      /* 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;
 +              }
 +      }
 +
 +      if (fast_forward_only)
 +              die(_("Not possible to fast-forward, aborting."));
 +
 +      /* 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_errno(_("Could not open '%s' for writing"),
 +                                git_path("MERGE_HEAD"));
 +              if (write_in_full(fd, buf.buf, buf.len) != buf.len)
 +                      die_errno(_("Could not write to '%s'"), git_path("MERGE_HEAD"));
 +              close(fd);
 +              strbuf_addch(&merge_msg, '\n');
 +              write_merge_msg();
 +              fd = open(git_path("MERGE_MODE"), O_WRONLY | O_CREAT | O_TRUNC, 0666);
 +              if (fd < 0)
 +                      die_errno(_("Could not open '%s' for writing"),
 +                                git_path("MERGE_MODE"));
 +              strbuf_reset(&buf);
 +              if (!allow_fast_forward)
 +                      strbuf_addf(&buf, "no-ff");
 +              if (write_in_full(fd, buf.buf, buf.len) != buf.len)
 +                      die_errno(_("Could not write to '%s'"), git_path("MERGE_MODE"));
 +              close(fd);
 +      }
 +
 +      if (merge_was_ok) {
 +              fprintf(stderr, _("Automatic merge went well; "
 +                      "stopped before committing as requested\n"));
 +              return 0;
 +      } else
 +              return suggest_conflicts(option_renormalize);
 +}
index 87d5d788cb1884fdfe218ec30582f5d3da8b5d7d,56c653d020be7c6096a6683bf67812dce8169b15..46b61ec3edbe68b350fa0a49b387269dc2c4c5d6
@@@ -322,8 -370,40 +322,41 @@@ test_expect_success 'merge c1 with c2 (
        verify_mergeheads $c2
  '
  
 -test_debug 'gitk --all'
 +test_debug 'git log --graph --decorate --oneline --all'
  
 -      (
 -              git config --remove-section branch.master
 -              git config --remove-section merge
 -      )
+ test_expect_success 'merge c1 with c2 (log in config)' '
+       git config branch.master.mergeoptions "" &&
+       git reset --hard c1 &&
+       git merge --log c2 &&
+       git show -s --pretty=tformat:%s%n%b >expect &&
+       git config branch.master.mergeoptions --log &&
+       git reset --hard c1 &&
+       git merge c2 &&
+       git show -s --pretty=tformat:%s%n%b >actual &&
+       test_cmp expect actual
+ '
+ test_expect_success 'merge c1 with c2 (log in config gets overridden)' '
++      test_when_finished "git config --remove-section branch.master" &&
++      test_when_finished "git config --remove-section merge" &&
++      test_might_fail git config --remove-section branch.master &&
++      test_might_fail git config --remove-section merge &&
++
+       git reset --hard c1 &&
+       git merge c2 &&
+       git show -s --pretty=tformat:%s%n%b >expect &&
+       git config branch.master.mergeoptions "--no-log" &&
+       git config merge.log true &&
+       git reset --hard c1 &&
+       git merge c2 &&
+       git show -s --pretty=tformat:%s%n%b >actual &&
+       test_cmp expect actual
+ '
  test_expect_success 'merge c1 with c2 (squash in config)' '
        git reset --hard c1 &&
        git config branch.master.mergeoptions "--squash" &&