Merge branch 'sb/reset-recurse-submodules'
authorJunio C Hamano <gitster@pobox.com>
Mon, 29 May 2017 03:34:40 +0000 (12:34 +0900)
committerJunio C Hamano <gitster@pobox.com>
Mon, 29 May 2017 03:34:40 +0000 (12:34 +0900)
"git reset" learned "--recurse-submodules" option.

* sb/reset-recurse-submodules:
builtin/reset: add --recurse-submodules switch
submodule.c: submodule_move_head works with broken submodules
submodule.c: uninitialized submodules are ignored in recursive commands
entry.c: submodule recursing: respect force flag correctly

1  2 
submodule.c
unpack-trees.c
diff --combined submodule.c
index 7eaa3d384e91b13f8380878aaf82e0c0d2caf4ab,20ed5b5681d3217246acf80bb0cc57a39d395c8f..54825100b29bd6bb9614bd2ab2431c6d418945b0
  #include "blob.h"
  #include "thread-utils.h"
  #include "quote.h"
 +#include "remote.h"
  #include "worktree.h"
  
  static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
  static int config_update_recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
  static int parallel_jobs = 1;
 -static struct string_list changed_submodule_paths = STRING_LIST_INIT_NODUP;
 +static struct string_list changed_submodule_paths = STRING_LIST_INIT_DUP;
  static int initialized_fetch_ref_tips;
 -static struct sha1_array ref_tips_before_fetch;
 -static struct sha1_array ref_tips_after_fetch;
 +static struct oid_array ref_tips_before_fetch;
 +static struct oid_array ref_tips_after_fetch;
  
  /*
   * The following flag is set if the .gitmodules file is unmerged. We then
@@@ -617,163 -616,41 +617,163 @@@ const struct submodule *submodule_from_
        return submodule_from_path(null_sha1, ce->name);
  }
  
 +static struct oid_array *submodule_commits(struct string_list *submodules,
 +                                         const char *path)
 +{
 +      struct string_list_item *item;
 +
 +      item = string_list_insert(submodules, path);
 +      if (item->util)
 +              return (struct oid_array *) item->util;
 +
 +      /* NEEDSWORK: should we have oid_array_init()? */
 +      item->util = xcalloc(1, sizeof(struct oid_array));
 +      return (struct oid_array *) item->util;
 +}
 +
 +static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 +                                        struct diff_options *options,
 +                                        void *data)
 +{
 +      int i;
 +      struct string_list *changed = data;
 +
 +      for (i = 0; i < q->nr; i++) {
 +              struct diff_filepair *p = q->queue[i];
 +              struct oid_array *commits;
 +              if (!S_ISGITLINK(p->two->mode))
 +                      continue;
 +
 +              if (S_ISGITLINK(p->one->mode)) {
 +                      /*
 +                       * NEEDSWORK: We should honor the name configured in
 +                       * the .gitmodules file of the commit we are examining
 +                       * here to be able to correctly follow submodules
 +                       * being moved around.
 +                       */
 +                      commits = submodule_commits(changed, p->two->path);
 +                      oid_array_append(commits, &p->two->oid);
 +              } else {
 +                      /* Submodule is new or was moved here */
 +                      /*
 +                       * NEEDSWORK: When the .git directories of submodules
 +                       * live inside the superprojects .git directory some
 +                       * day we should fetch new submodules directly into
 +                       * that location too when config or options request
 +                       * that so they can be checked out from there.
 +                       */
 +                      continue;
 +              }
 +      }
 +}
 +
 +/*
 + * Collect the paths of submodules in 'changed' which have changed based on
 + * the revisions as specified in 'argv'.  Each entry in 'changed' will also
 + * have a corresponding 'struct oid_array' (in the 'util' field) which lists
 + * what the submodule pointers were updated to during the change.
 + */
 +static void collect_changed_submodules(struct string_list *changed,
 +                                     struct argv_array *argv)
 +{
 +      struct rev_info rev;
 +      const struct commit *commit;
 +
 +      init_revisions(&rev, NULL);
 +      setup_revisions(argv->argc, argv->argv, &rev, NULL);
 +      if (prepare_revision_walk(&rev))
 +              die("revision walk setup failed");
 +
 +      while ((commit = get_revision(&rev))) {
 +              struct rev_info diff_rev;
 +
 +              init_revisions(&diff_rev, NULL);
 +              diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 +              diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
 +              diff_rev.diffopt.format_callback_data = changed;
 +              diff_tree_combined_merge(commit, 1, &diff_rev);
 +      }
 +
 +      reset_revision_walk();
 +}
 +
 +static void free_submodules_oids(struct string_list *submodules)
 +{
 +      struct string_list_item *item;
 +      for_each_string_list_item(item, submodules)
 +              oid_array_clear((struct oid_array *) item->util);
 +      string_list_clear(submodules, 1);
 +}
 +
  static int has_remote(const char *refname, const struct object_id *oid,
                      int flags, void *cb_data)
  {
        return 1;
  }
  
 -static int append_sha1_to_argv(const unsigned char sha1[20], void *data)
 +static int append_oid_to_argv(const struct object_id *oid, void *data)
  {
        struct argv_array *argv = data;
 -      argv_array_push(argv, sha1_to_hex(sha1));
 +      argv_array_push(argv, oid_to_hex(oid));
        return 0;
  }
  
 -static int check_has_commit(const unsigned char sha1[20], void *data)
 +static int check_has_commit(const struct object_id *oid, void *data)
  {
        int *has_commit = data;
  
 -      if (!lookup_commit_reference(sha1))
 +      if (!lookup_commit_reference(oid->hash))
                *has_commit = 0;
  
        return 0;
  }
  
 -static int submodule_has_commits(const char *path, struct sha1_array *commits)
 +static int submodule_has_commits(const char *path, struct oid_array *commits)
  {
        int has_commit = 1;
  
 +      /*
 +       * Perform a cheap, but incorrect check for the existance of 'commits'.
 +       * This is done by adding the submodule's object store to the in-core
 +       * object store, and then querying for each commit's existance.  If we
 +       * do not have the commit object anywhere, there is no chance we have
 +       * it in the object store of the correct submodule and have it
 +       * reachable from a ref, so we can fail early without spawning rev-list
 +       * which is expensive.
 +       */
        if (add_submodule_odb(path))
                return 0;
  
 -      sha1_array_for_each_unique(commits, check_has_commit, &has_commit);
 +      oid_array_for_each_unique(commits, check_has_commit, &has_commit);
 +
 +      if (has_commit) {
 +              /*
 +               * Even if the submodule is checked out and the commit is
 +               * present, make sure it exists in the submodule's object store
 +               * and that it is reachable from a ref.
 +               */
 +              struct child_process cp = CHILD_PROCESS_INIT;
 +              struct strbuf out = STRBUF_INIT;
 +
 +              argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
 +              oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 +              argv_array_pushl(&cp.args, "--not", "--all", NULL);
 +
 +              prepare_submodule_repo_env(&cp.env_array);
 +              cp.git_cmd = 1;
 +              cp.no_stdin = 1;
 +              cp.dir = path;
 +
 +              if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
 +                      has_commit = 0;
 +
 +              strbuf_release(&out);
 +      }
 +
        return has_commit;
  }
  
 -static int submodule_needs_pushing(const char *path, struct sha1_array *commits)
 +static int submodule_needs_pushing(const char *path, struct oid_array *commits)
  {
        if (!submodule_has_commits(path, commits))
                /*
                int needs_pushing = 0;
  
                argv_array_push(&cp.args, "rev-list");
 -              sha1_array_for_each_unique(commits, append_sha1_to_argv, &cp.args);
 +              oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
                argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
  
                prepare_submodule_repo_env(&cp.env_array);
        return 0;
  }
  
 -static struct sha1_array *submodule_commits(struct string_list *submodules,
 -                                          const char *path)
 -{
 -      struct string_list_item *item;
 -
 -      item = string_list_insert(submodules, path);
 -      if (item->util)
 -              return (struct sha1_array *) item->util;
 -
 -      /* NEEDSWORK: should we have sha1_array_init()? */
 -      item->util = xcalloc(1, sizeof(struct sha1_array));
 -      return (struct sha1_array *) item->util;
 -}
 -
 -static void collect_submodules_from_diff(struct diff_queue_struct *q,
 -                                       struct diff_options *options,
 -                                       void *data)
 -{
 -      int i;
 -      struct string_list *submodules = data;
 -
 -      for (i = 0; i < q->nr; i++) {
 -              struct diff_filepair *p = q->queue[i];
 -              struct sha1_array *commits;
 -              if (!S_ISGITLINK(p->two->mode))
 -                      continue;
 -              commits = submodule_commits(submodules, p->two->path);
 -              sha1_array_append(commits, p->two->oid.hash);
 -      }
 -}
 -
 -static void find_unpushed_submodule_commits(struct commit *commit,
 -              struct string_list *needs_pushing)
 -{
 -      struct rev_info rev;
 -
 -      init_revisions(&rev, NULL);
 -      rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 -      rev.diffopt.format_callback = collect_submodules_from_diff;
 -      rev.diffopt.format_callback_data = needs_pushing;
 -      diff_tree_combined_merge(commit, 1, &rev);
 -}
 -
 -static void free_submodules_sha1s(struct string_list *submodules)
 -{
 -      struct string_list_item *item;
 -      for_each_string_list_item(item, submodules)
 -              sha1_array_clear((struct sha1_array *) item->util);
 -      string_list_clear(submodules, 1);
 -}
 -
 -int find_unpushed_submodules(struct sha1_array *commits,
 +int find_unpushed_submodules(struct oid_array *commits,
                const char *remotes_name, struct string_list *needs_pushing)
  {
 -      struct rev_info rev;
 -      struct commit *commit;
        struct string_list submodules = STRING_LIST_INIT_DUP;
        struct string_list_item *submodule;
        struct argv_array argv = ARGV_ARRAY_INIT;
  
 -      init_revisions(&rev, NULL);
 -
        /* argv.argv[0] will be ignored by setup_revisions */
        argv_array_push(&argv, "find_unpushed_submodules");
 -      sha1_array_for_each_unique(commits, append_sha1_to_argv, &argv);
 +      oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
        argv_array_push(&argv, "--not");
        argv_array_pushf(&argv, "--remotes=%s", remotes_name);
  
 -      setup_revisions(argv.argc, argv.argv, &rev, NULL);
 -      if (prepare_revision_walk(&rev))
 -              die("revision walk setup failed");
 -
 -      while ((commit = get_revision(&rev)) != NULL)
 -              find_unpushed_submodule_commits(commit, &submodules);
 -
 -      reset_revision_walk();
 -      argv_array_clear(&argv);
 +      collect_changed_submodules(&submodules, &argv);
  
        for_each_string_list_item(submodule, &submodules) {
 -              struct sha1_array *commits = (struct sha1_array *) submodule->util;
 +              struct oid_array *commits = submodule->util;
 +              const char *path = submodule->string;
  
 -              if (submodule_needs_pushing(submodule->string, commits))
 -                      string_list_insert(needs_pushing, submodule->string);
 +              if (submodule_needs_pushing(path, commits))
 +                      string_list_insert(needs_pushing, path);
        }
 -      free_submodules_sha1s(&submodules);
 +
 +      free_submodules_oids(&submodules);
 +      argv_array_clear(&argv);
  
        return needs_pushing->nr;
  }
  
 -static int push_submodule(const char *path, int dry_run)
 +static int push_submodule(const char *path,
 +                        const struct remote *remote,
 +                        const char **refspec, int refspec_nr,
 +                        const struct string_list *push_options,
 +                        int dry_run)
  {
        if (add_submodule_odb(path))
                return 1;
                if (dry_run)
                        argv_array_push(&cp.args, "--dry-run");
  
 +              if (push_options && push_options->nr) {
 +                      const struct string_list_item *item;
 +                      for_each_string_list_item(item, push_options)
 +                              argv_array_pushf(&cp.args, "--push-option=%s",
 +                                               item->string);
 +              }
 +
 +              if (remote->origin != REMOTE_UNCONFIGURED) {
 +                      int i;
 +                      argv_array_push(&cp.args, remote->name);
 +                      for (i = 0; i < refspec_nr; i++)
 +                              argv_array_push(&cp.args, refspec[i]);
 +              }
 +
                prepare_submodule_repo_env(&cp.env_array);
                cp.git_cmd = 1;
                cp.no_stdin = 1;
        return 1;
  }
  
 -int push_unpushed_submodules(struct sha1_array *commits,
 -                           const char *remotes_name,
 +/*
 + * Perform a check in the submodule to see if the remote and refspec work.
 + * Die if the submodule can't be pushed.
 + */
 +static void submodule_push_check(const char *path, const struct remote *remote,
 +                               const char **refspec, int refspec_nr)
 +{
 +      struct child_process cp = CHILD_PROCESS_INIT;
 +      int i;
 +
 +      argv_array_push(&cp.args, "submodule--helper");
 +      argv_array_push(&cp.args, "push-check");
 +      argv_array_push(&cp.args, remote->name);
 +
 +      for (i = 0; i < refspec_nr; i++)
 +              argv_array_push(&cp.args, refspec[i]);
 +
 +      prepare_submodule_repo_env(&cp.env_array);
 +      cp.git_cmd = 1;
 +      cp.no_stdin = 1;
 +      cp.no_stdout = 1;
 +      cp.dir = path;
 +
 +      /*
 +       * Simply indicate if 'submodule--helper push-check' failed.
 +       * More detailed error information will be provided by the
 +       * child process.
 +       */
 +      if (run_command(&cp))
 +              die("process for submodule '%s' failed", path);
 +}
 +
 +int push_unpushed_submodules(struct oid_array *commits,
 +                           const struct remote *remote,
 +                           const char **refspec, int refspec_nr,
 +                           const struct string_list *push_options,
                             int dry_run)
  {
        int i, ret = 1;
        struct string_list needs_pushing = STRING_LIST_INIT_DUP;
  
 -      if (!find_unpushed_submodules(commits, remotes_name, &needs_pushing))
 +      if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
                return 1;
  
 +      /*
 +       * Verify that the remote and refspec can be propagated to all
 +       * submodules.  This check can be skipped if the remote and refspec
 +       * won't be propagated due to the remote being unconfigured (e.g. a URL
 +       * instead of a remote name).
 +       */
 +      if (remote->origin != REMOTE_UNCONFIGURED)
 +              for (i = 0; i < needs_pushing.nr; i++)
 +                      submodule_push_check(needs_pushing.items[i].string,
 +                                           remote, refspec, refspec_nr);
 +
 +      /* Actually push the submodules */
        for (i = 0; i < needs_pushing.nr; i++) {
                const char *path = needs_pushing.items[i].string;
                fprintf(stderr, "Pushing submodule '%s'\n", path);
 -              if (!push_submodule(path, dry_run)) {
 +              if (!push_submodule(path, remote, refspec, refspec_nr,
 +                                  push_options, dry_run)) {
                        fprintf(stderr, "Unable to push submodule '%s'\n", path);
                        ret = 0;
                }
        return ret;
  }
  
 -static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
 -{
 -      int is_present = 0;
 -      if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
 -              /* Even if the submodule is checked out and the commit is
 -               * present, make sure it is reachable from a ref. */
 -              struct child_process cp = CHILD_PROCESS_INIT;
 -              const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
 -              struct strbuf buf = STRBUF_INIT;
 -
 -              argv[3] = sha1_to_hex(sha1);
 -              cp.argv = argv;
 -              prepare_submodule_repo_env(&cp.env_array);
 -              cp.git_cmd = 1;
 -              cp.no_stdin = 1;
 -              cp.dir = path;
 -              if (!capture_command(&cp, &buf, 1024) && !buf.len)
 -                      is_present = 1;
 -
 -              strbuf_release(&buf);
 -      }
 -      return is_present;
 -}
 -
 -static void submodule_collect_changed_cb(struct diff_queue_struct *q,
 -                                       struct diff_options *options,
 -                                       void *data)
 +static int append_oid_to_array(const char *ref, const struct object_id *oid,
 +                             int flags, void *data)
  {
 -      int i;
 -      for (i = 0; i < q->nr; i++) {
 -              struct diff_filepair *p = q->queue[i];
 -              if (!S_ISGITLINK(p->two->mode))
 -                      continue;
 -
 -              if (S_ISGITLINK(p->one->mode)) {
 -                      /* NEEDSWORK: We should honor the name configured in
 -                       * the .gitmodules file of the commit we are examining
 -                       * here to be able to correctly follow submodules
 -                       * being moved around. */
 -                      struct string_list_item *path;
 -                      path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
 -                      if (!path && !is_submodule_commit_present(p->two->path, p->two->oid.hash))
 -                              string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
 -              } else {
 -                      /* Submodule is new or was moved here */
 -                      /* NEEDSWORK: When the .git directories of submodules
 -                       * live inside the superprojects .git directory some
 -                       * day we should fetch new submodules directly into
 -                       * that location too when config or options request
 -                       * that so they can be checked out from there. */
 -                      continue;
 -              }
 -      }
 -}
 -
 -static int add_sha1_to_array(const char *ref, const struct object_id *oid,
 -                           int flags, void *data)
 -{
 -      sha1_array_append(data, oid->hash);
 +      struct oid_array *array = data;
 +      oid_array_append(array, oid);
        return 0;
  }
  
 -void check_for_new_submodule_commits(unsigned char new_sha1[20])
 +void check_for_new_submodule_commits(struct object_id *oid)
  {
        if (!initialized_fetch_ref_tips) {
 -              for_each_ref(add_sha1_to_array, &ref_tips_before_fetch);
 +              for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
                initialized_fetch_ref_tips = 1;
        }
  
 -      sha1_array_append(&ref_tips_after_fetch, new_sha1);
 -}
 -
 -static int add_sha1_to_argv(const unsigned char sha1[20], void *data)
 -{
 -      argv_array_push(data, sha1_to_hex(sha1));
 -      return 0;
 +      oid_array_append(&ref_tips_after_fetch, oid);
  }
  
  static void calculate_changed_submodule_paths(void)
  {
 -      struct rev_info rev;
 -      struct commit *commit;
        struct argv_array argv = ARGV_ARRAY_INIT;
 +      struct string_list changed_submodules = STRING_LIST_INIT_DUP;
 +      const struct string_list_item *item;
  
        /* No need to check if there are no submodules configured */
        if (!submodule_from_path(NULL, NULL))
                return;
  
 -      init_revisions(&rev, NULL);
        argv_array_push(&argv, "--"); /* argv[0] program name */
 -      sha1_array_for_each_unique(&ref_tips_after_fetch,
 -                                 add_sha1_to_argv, &argv);
 +      oid_array_for_each_unique(&ref_tips_after_fetch,
 +                                 append_oid_to_argv, &argv);
        argv_array_push(&argv, "--not");
 -      sha1_array_for_each_unique(&ref_tips_before_fetch,
 -                                 add_sha1_to_argv, &argv);
 -      setup_revisions(argv.argc, argv.argv, &rev, NULL);
 -      if (prepare_revision_walk(&rev))
 -              die("revision walk setup failed");
 +      oid_array_for_each_unique(&ref_tips_before_fetch,
 +                                 append_oid_to_argv, &argv);
  
        /*
         * Collect all submodules (whether checked out or not) for which new
         * commits have been recorded upstream in "changed_submodule_paths".
         */
 -      while ((commit = get_revision(&rev))) {
 -              struct commit_list *parent = commit->parents;
 -              while (parent) {
 -                      struct diff_options diff_opts;
 -                      diff_setup(&diff_opts);
 -                      DIFF_OPT_SET(&diff_opts, RECURSIVE);
 -                      diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
 -                      diff_opts.format_callback = submodule_collect_changed_cb;
 -                      diff_setup_done(&diff_opts);
 -                      diff_tree_sha1(parent->item->object.oid.hash, commit->object.oid.hash, "", &diff_opts);
 -                      diffcore_std(&diff_opts);
 -                      diff_flush(&diff_opts);
 -                      parent = parent->next;
 -              }
 +      collect_changed_submodules(&changed_submodules, &argv);
 +
 +      for_each_string_list_item(item, &changed_submodules) {
 +              struct oid_array *commits = item->util;
 +              const char *path = item->string;
 +
 +              if (!submodule_has_commits(path, commits))
 +                      string_list_append(&changed_submodule_paths, path);
        }
  
 +      free_submodules_oids(&changed_submodules);
        argv_array_clear(&argv);
 -      sha1_array_clear(&ref_tips_before_fetch);
 -      sha1_array_clear(&ref_tips_after_fetch);
 +      oid_array_clear(&ref_tips_before_fetch);
 +      oid_array_clear(&ref_tips_after_fetch);
        initialized_fetch_ref_tips = 0;
  }
  
  
  unsigned is_submodule_modified(const char *path, int ignore_untracked)
  {
 -      ssize_t len;
        struct child_process cp = CHILD_PROCESS_INIT;
 -      const char *argv[] = {
 -              "status",
 -              "--porcelain",
 -              NULL,
 -              NULL,
 -      };
        struct strbuf buf = STRBUF_INIT;
 +      FILE *fp;
        unsigned dirty_submodule = 0;
 -      const char *line, *next_line;
        const char *git_dir;
 +      int ignore_cp_exit_code = 0;
  
        strbuf_addf(&buf, "%s/.git", path);
        git_dir = read_gitfile(buf.buf);
        if (!git_dir)
                git_dir = buf.buf;
 -      if (!is_directory(git_dir)) {
 +      if (!is_git_directory(git_dir)) {
 +              if (is_directory(git_dir))
 +                      die(_("'%s' not recognized as a git repository"), git_dir);
                strbuf_release(&buf);
                /* The submodule is not checked out, so it is not modified */
                return 0;
 -
        }
        strbuf_reset(&buf);
  
 +      argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
        if (ignore_untracked)
 -              argv[2] = "-uno";
 +              argv_array_push(&cp.args, "-uno");
  
 -      cp.argv = argv;
        prepare_submodule_repo_env(&cp.env_array);
        cp.git_cmd = 1;
        cp.no_stdin = 1;
        cp.out = -1;
        cp.dir = path;
        if (start_command(&cp))
 -              die("Could not run 'git status --porcelain' in submodule %s", path);
 +              die("Could not run 'git status --porcelain=2' in submodule %s", path);
  
 -      len = strbuf_read(&buf, cp.out, 1024);
 -      line = buf.buf;
 -      while (len > 2) {
 -              if ((line[0] == '?') && (line[1] == '?')) {
 +      fp = xfdopen(cp.out, "r");
 +      while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
 +              /* regular untracked files */
 +              if (buf.buf[0] == '?')
                        dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
 -                      if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 -                              break;
 -              } else {
 -                      dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
 -                      if (ignore_untracked ||
 -                          (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
 -                              break;
 +
 +              if (buf.buf[0] == 'u' ||
 +                  buf.buf[0] == '1' ||
 +                  buf.buf[0] == '2') {
 +                      /* T = line type, XY = status, SSSS = submodule state */
 +                      if (buf.len < strlen("T XY SSSS"))
 +                              die("BUG: invalid status --porcelain=2 line %s",
 +                                  buf.buf);
 +
 +                      if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
 +                              /* nested untracked file */
 +                              dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
 +
 +                      if (buf.buf[0] == 'u' ||
 +                          buf.buf[0] == '2' ||
 +                          memcmp(buf.buf + 5, "S..U", 4))
 +                              /* other change */
 +                              dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
                }
 -              next_line = strchr(line, '\n');
 -              if (!next_line)
 +
 +              if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
 +                  ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
 +                   ignore_untracked)) {
 +                      /*
 +                       * We're not interested in any further information from
 +                       * the child any more, neither output nor its exit code.
 +                       */
 +                      ignore_cp_exit_code = 1;
                        break;
 -              next_line++;
 -              len -= (next_line - line);
 -              line = next_line;
 +              }
        }
 -      close(cp.out);
 +      fclose(fp);
  
 -      if (finish_command(&cp))
 -              die("'git status --porcelain' failed in submodule %s", path);
 +      if (finish_command(&cp) && !ignore_cp_exit_code)
 +              die("'git status --porcelain=2' failed in submodule %s", path);
  
        strbuf_release(&buf);
        return dirty_submodule;
@@@ -1322,7 -1252,7 +1322,7 @@@ int bad_to_remove_submodule(const char 
        cp.dir = path;
        if (start_command(&cp)) {
                if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
 -                      die(_("could not start 'git status in submodule '%s'"),
 +                      die(_("could not start 'git status' in submodule '%s'"),
                                path);
                ret = -1;
                goto out;
  
        if (finish_command(&cp)) {
                if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
 -                      die(_("could not run 'git status in submodule '%s'"),
 +                      die(_("could not run 'git status' in submodule '%s'"),
                                path);
                ret = -1;
        }
@@@ -1402,6 -1332,23 +1402,23 @@@ int submodule_move_head(const char *pat
        int ret = 0;
        struct child_process cp = CHILD_PROCESS_INIT;
        const struct submodule *sub;
+       int *error_code_ptr, error_code;
+       if (!is_submodule_initialized(path))
+               return 0;
+       if (flags & SUBMODULE_MOVE_HEAD_FORCE)
+               /*
+                * Pass non NULL pointer to is_submodule_populated_gently
+                * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
+                * to fixup the submodule in the force case later.
+                */
+               error_code_ptr = &error_code;
+       else
+               error_code_ptr = NULL;
+       if (old && !is_submodule_populated_gently(path, error_code_ptr))
+               return 0;
  
        sub = submodule_from_path(null_sha1, path);
  
                                absorb_git_dir_into_superproject("", path,
                                        ABSORB_GITDIR_RECURSE_SUBMODULES);
                } else {
-                       struct strbuf sb = STRBUF_INIT;
-                       strbuf_addf(&sb, "%s/modules/%s",
+                       char *gitdir = xstrfmt("%s/modules/%s",
                                    get_git_common_dir(), sub->name);
-                       connect_work_tree_and_git_dir(path, sb.buf);
-                       strbuf_release(&sb);
+                       connect_work_tree_and_git_dir(path, gitdir);
+                       free(gitdir);
  
                        /* make sure the index is clean as well */
                        submodule_reset_index(path);
                }
+               if (old && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
+                       char *gitdir = xstrfmt("%s/modules/%s",
+                                   get_git_common_dir(), sub->name);
+                       connect_work_tree_and_git_dir(path, gitdir);
+                       free(gitdir);
+               }
        }
  
        prepare_submodule_repo_env_no_git_dir(&cp.env_array);
                        cp1.no_stdin = 1;
                        cp1.dir = path;
  
 -                      argv_array_pushl(&cp1.args, "update-ref", "HEAD",
 -                                       new ? new : EMPTY_TREE_SHA1_HEX, NULL);
 +                      argv_array_pushl(&cp1.args, "update-ref", "HEAD", new, NULL);
  
                        if (run_command(&cp1)) {
                                ret = -1;
@@@ -1858,34 -1812,3 +1881,34 @@@ const char *get_superproject_working_tr
  
        return ret;
  }
 +
 +int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
 +{
 +      const struct submodule *sub;
 +      const char *git_dir;
 +      int ret = 0;
 +
 +      strbuf_reset(buf);
 +      strbuf_addstr(buf, submodule);
 +      strbuf_complete(buf, '/');
 +      strbuf_addstr(buf, ".git");
 +
 +      git_dir = read_gitfile(buf->buf);
 +      if (git_dir) {
 +              strbuf_reset(buf);
 +              strbuf_addstr(buf, git_dir);
 +      }
 +      if (!is_git_directory(buf->buf)) {
 +              gitmodules_config();
 +              sub = submodule_from_path(null_sha1, submodule);
 +              if (!sub) {
 +                      ret = -1;
 +                      goto cleanup;
 +              }
 +              strbuf_reset(buf);
 +              strbuf_git_path(buf, "%s/%s", "modules", sub->name);
 +      }
 +
 +cleanup:
 +      return ret;
 +}
diff --combined unpack-trees.c
index aa15111fefc8ca333edeeeb3ac77a8b946e4c6a5,4b3f9518e5f9fdda1ec300f527e18022e221d215..d98a4f4d8668d989d34e5b938947704836ae8c84
@@@ -252,14 -252,18 +252,18 @@@ static int check_submodule_move_head(co
                                     const char *new_id,
                                     struct unpack_trees_options *o)
  {
+       unsigned flags = SUBMODULE_MOVE_HEAD_DRY_RUN;
        const struct submodule *sub = submodule_from_ce(ce);
        if (!sub)
                return 0;
  
+       if (o->reset)
+               flags |= SUBMODULE_MOVE_HEAD_FORCE;
        switch (sub->update_strategy.type) {
        case SM_UPDATE_UNSPECIFIED:
        case SM_UPDATE_CHECKOUT:
-               if (submodule_move_head(ce->name, old_id, new_id, SUBMODULE_MOVE_HEAD_DRY_RUN))
+               if (submodule_move_head(ce->name, old_id, new_id, flags))
                        return o->gently ? -1 :
                                add_rejected_path(o, ERROR_WOULD_LOSE_SUBMODULE, ce->name);
                return 0;
@@@ -308,6 -312,7 +312,7 @@@ static void unlink_entry(const struct c
                case SM_UPDATE_CHECKOUT:
                case SM_UPDATE_REBASE:
                case SM_UPDATE_MERGE:
+                       /* state.force is set at the caller. */
                        submodule_move_head(ce->name, "HEAD", NULL,
                                            SUBMODULE_MOVE_HEAD_FORCE);
                        break;
@@@ -604,18 -609,12 +609,18 @@@ static int switch_cache_bottom(struct t
        return ret;
  }
  
 +static inline int are_same_oid(struct name_entry *name_j, struct name_entry *name_k)
 +{
 +      return name_j->oid && name_k->oid && !oidcmp(name_j->oid, name_k->oid);
 +}
 +
  static int traverse_trees_recursive(int n, unsigned long dirmask,
                                    unsigned long df_conflicts,
                                    struct name_entry *names,
                                    struct traverse_info *info)
  {
        int i, ret, bottom;
 +      int nr_buf = 0;
        struct tree_desc t[MAX_UNPACK_TREES];
        void *buf[MAX_UNPACK_TREES];
        struct traverse_info newinfo;
        newinfo.pathlen += tree_entry_len(p) + 1;
        newinfo.df_conflicts |= df_conflicts;
  
 +      /*
 +       * Fetch the tree from the ODB for each peer directory in the
 +       * n commits.
 +       *
 +       * For 2- and 3-way traversals, we try to avoid hitting the
 +       * ODB twice for the same OID.  This should yield a nice speed
 +       * up in checkouts and merges when the commits are similar.
 +       *
 +       * We don't bother doing the full O(n^2) search for larger n,
 +       * because wider traversals don't happen that often and we
 +       * avoid the search setup.
 +       *
 +       * When 2 peer OIDs are the same, we just copy the tree
 +       * descriptor data.  This implicitly borrows the buffer
 +       * data from the earlier cell.
 +       */
        for (i = 0; i < n; i++, dirmask >>= 1) {
 -              const unsigned char *sha1 = NULL;
 -              if (dirmask & 1)
 -                      sha1 = names[i].oid->hash;
 -              buf[i] = fill_tree_descriptor(t+i, sha1);
 +              if (i > 0 && are_same_oid(&names[i], &names[i - 1]))
 +                      t[i] = t[i - 1];
 +              else if (i > 1 && are_same_oid(&names[i], &names[i - 2]))
 +                      t[i] = t[i - 2];
 +              else {
 +                      const unsigned char *sha1 = NULL;
 +                      if (dirmask & 1)
 +                              sha1 = names[i].oid->hash;
 +                      buf[nr_buf++] = fill_tree_descriptor(t+i, sha1);
 +              }
        }
  
        bottom = switch_cache_bottom(&newinfo);
        ret = traverse_trees(n, t, &newinfo);
        restore_cache_bottom(&newinfo, bottom);
  
 -      for (i = 0; i < n; i++)
 +      for (i = 0; i < nr_buf; i++)
                free(buf[i]);
  
        return ret;