Merge branch 'ja/do-not-ask-needless-questions'
[gitweb.git] / setup.c
diff --git a/setup.c b/setup.c
index 1a374f2bf4f986b00727ee04da6a65f8f914e35f..e3f7699a902aed20a83820067cf913df2f3750a9 100644 (file)
--- a/setup.c
+++ b/setup.c
@@ -5,7 +5,9 @@
 static int inside_git_dir = -1;
 static int inside_work_tree = -1;
 static int work_tree_config_is_bogus;
-static struct string_list unknown_extensions = STRING_LIST_INIT_DUP;
+
+static struct startup_info the_startup_info;
+struct startup_info *startup_info = &the_startup_info;
 
 /*
  * The input parameter must contain an absolute path, and it must already be
@@ -88,7 +90,7 @@ char *prefix_path_gently(const char *prefix, int len,
        const char *orig = path;
        char *sanitized;
        if (is_absolute_path(orig)) {
-               sanitized = xmalloc(strlen(path) + 1);
+               sanitized = xmallocz(strlen(path));
                if (remaining_prefix)
                        *remaining_prefix = 0;
                if (normalize_path_copy_len(sanitized, path, remaining_prefix)) {
@@ -100,10 +102,7 @@ char *prefix_path_gently(const char *prefix, int len,
                        return NULL;
                }
        } else {
-               sanitized = xmalloc(len + strlen(path) + 1);
-               if (len)
-                       memcpy(sanitized, prefix, len);
-               strcpy(sanitized + len, path);
+               sanitized = xstrfmt("%.*s%s", len, len ? prefix : "", path);
                if (remaining_prefix)
                        *remaining_prefix = len;
                if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) {
@@ -136,22 +135,25 @@ int path_inside_repo(const char *prefix, const char *path)
 int check_filename(const char *prefix, const char *arg)
 {
        const char *name;
+       char *to_free = NULL;
        struct stat st;
 
        if (starts_with(arg, ":/")) {
                if (arg[2] == '\0') /* ":/" is root dir, always exists */
                        return 1;
                name = arg + 2;
-       } else if (!no_wildcard(arg))
-               return 1;
-       else if (prefix)
-               name = prefix_filename(prefix, strlen(prefix), arg);
+       } else if (prefix)
+               name = to_free = prefix_filename(prefix, arg);
        else
                name = arg;
-       if (!lstat(name, &st))
+       if (!lstat(name, &st)) {
+               free(to_free);
                return 1; /* file exists */
-       if (errno == ENOENT || errno == ENOTDIR)
+       }
+       if (errno == ENOENT || errno == ENOTDIR) {
+               free(to_free);
                return 0; /* file does not exist */
+       }
        die_errno("failed to stat '%s'", arg);
 }
 
@@ -160,8 +162,8 @@ static void NORETURN die_verify_filename(const char *prefix,
                                         int diagnose_misspelt_rev)
 {
        if (!diagnose_misspelt_rev)
-               die("%s: no such path in the working tree.\n"
-                   "Use 'git <command> -- <path>...' to specify paths that do not exist locally.",
+               die(_("%s: no such path in the working tree.\n"
+                     "Use 'git <command> -- <path>...' to specify paths that do not exist locally."),
                    arg);
        /*
         * Saying "'(icase)foo' does not exist in the index" when the
@@ -173,9 +175,9 @@ static void NORETURN die_verify_filename(const char *prefix,
                maybe_die_on_misspelt_object_name(arg, prefix);
 
        /* ... or fall back the most general message. */
-       die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
-           "Use '--' to separate paths from revisions, like this:\n"
-           "'git <command> [<revision>...] -- [<file>...]'", arg);
+       die(_("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
+             "Use '--' to separate paths from revisions, like this:\n"
+             "'git <command> [<revision>...] -- [<file>...]'"), arg);
 
 }
 
@@ -205,7 +207,7 @@ void verify_filename(const char *prefix,
 {
        if (*arg == '-')
                die("bad flag '%s' used after filename", arg);
-       if (check_filename(prefix, arg))
+       if (check_filename(prefix, arg) || !no_wildcard(arg))
                return;
        die_verify_filename(prefix, arg, diagnose_misspelt_rev);
 }
@@ -223,9 +225,9 @@ void verify_non_filename(const char *prefix, const char *arg)
                return; /* flag */
        if (!check_filename(prefix, arg))
                return;
-       die("ambiguous argument '%s': both revision and filename\n"
-           "Use '--' to separate paths from revisions, like this:\n"
-           "'git <command> [<revision>...] -- [<file>...]'", arg);
+       die(_("ambiguous argument '%s': both revision and filename\n"
+             "Use '--' to separate paths from revisions, like this:\n"
+             "'git <command> [<revision>...] -- [<file>...]'"), arg);
 }
 
 int get_common_dir(struct strbuf *sb, const char *gitdir)
@@ -257,10 +259,12 @@ int get_common_dir_noenv(struct strbuf *sb, const char *gitdir)
                if (!is_absolute_path(data.buf))
                        strbuf_addf(&path, "%s/", gitdir);
                strbuf_addbuf(&path, &data);
-               strbuf_addstr(sb, real_path(path.buf));
+               strbuf_add_real_path(sb, path.buf);
                ret = 1;
-       } else
+       } else {
                strbuf_addstr(sb, gitdir);
+       }
+
        strbuf_release(&data);
        strbuf_release(&path);
        return ret;
@@ -315,6 +319,23 @@ int is_git_directory(const char *suspect)
        return ret;
 }
 
+int is_nonbare_repository_dir(struct strbuf *path)
+{
+       int ret = 0;
+       int gitfile_error;
+       size_t orig_path_len = path->len;
+       assert(orig_path_len != 0);
+       strbuf_complete(path, '/');
+       strbuf_addstr(path, ".git");
+       if (read_gitfile_gently(path->buf, &gitfile_error) || is_git_directory(path->buf))
+               ret = 1;
+       if (gitfile_error == READ_GITFILE_ERR_OPEN_FAILED ||
+           gitfile_error == READ_GITFILE_ERR_READ_FAILED)
+               ret = 1;
+       strbuf_setlen(path, orig_path_len);
+       return ret;
+}
+
 int is_inside_git_dir(void)
 {
        if (inside_git_dir < 0)
@@ -358,14 +379,13 @@ void setup_work_tree(void)
        initialized = 1;
 }
 
-static int check_repo_format(const char *var, const char *value, void *cb)
+static int check_repo_format(const char *var, const char *value, void *vdata)
 {
+       struct repository_format *data = vdata;
        const char *ext;
 
        if (strcmp(var, "core.repositoryformatversion") == 0)
-               repository_format_version = git_config_int(var, value);
-       else if (strcmp(var, "core.sharedrepository") == 0)
-               shared_repository = git_config_perm(var, value);
+               data->version = git_config_int(var, value);
        else if (skip_prefix(var, "extensions.", &ext)) {
                /*
                 * record any known extensions here; otherwise,
@@ -375,9 +395,15 @@ static int check_repo_format(const char *var, const char *value, void *cb)
                if (!strcmp(ext, "noop"))
                        ;
                else if (!strcmp(ext, "preciousobjects"))
-                       repository_format_precious_objects = git_config_bool(var, value);
+                       data->precious_objects = git_config_bool(var, value);
                else
-                       string_list_append(&unknown_extensions, ext);
+                       string_list_append(&data->unknown_extensions, ext);
+       } else if (strcmp(var, "core.bare") == 0) {
+               data->is_bare = git_config_bool(var, value);
+       } else if (strcmp(var, "core.worktree") == 0) {
+               if (!value)
+                       return config_error_nonbool(var);
+               data->work_tree = xstrdup(value);
        }
        return 0;
 }
@@ -385,67 +411,108 @@ static int check_repo_format(const char *var, const char *value, void *cb)
 static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 {
        struct strbuf sb = STRBUF_INIT;
-       const char *repo_config;
-       config_fn_t fn;
-       int ret = 0;
-
-       string_list_clear(&unknown_extensions, 0);
+       struct strbuf err = STRBUF_INIT;
+       struct repository_format candidate;
+       int has_common;
 
-       if (get_common_dir(&sb, gitdir))
-               fn = check_repo_format;
-       else
-               fn = check_repository_format_version;
+       has_common = get_common_dir(&sb, gitdir);
        strbuf_addstr(&sb, "/config");
-       repo_config = sb.buf;
+       read_repository_format(&candidate, sb.buf);
+       strbuf_release(&sb);
 
        /*
-        * git_config() can't be used here because it calls git_pathdup()
-        * to get $GIT_CONFIG/config. That call will make setup_git_env()
-        * set git_dir to ".git".
-        *
-        * We are in gitdir setup, no git dir has been found useable yet.
-        * Use a gentler version of git_config() to check if this repo
-        * is a good one.
+        * For historical use of check_repository_format() in git-init,
+        * we treat a missing config as a silent "ok", even when nongit_ok
+        * is unset.
         */
-       git_config_early(fn, NULL, repo_config);
-       if (GIT_REPO_VERSION_READ < repository_format_version) {
-               if (!nongit_ok)
-                       die ("Expected git repo version <= %d, found %d",
-                            GIT_REPO_VERSION_READ, repository_format_version);
-               warning("Expected git repo version <= %d, found %d",
-                       GIT_REPO_VERSION_READ, repository_format_version);
-               warning("Please upgrade Git");
-               *nongit_ok = -1;
-               ret = -1;
+       if (candidate.version < 0)
+               return 0;
+
+       if (verify_repository_format(&candidate, &err) < 0) {
+               if (nongit_ok) {
+                       warning("%s", err.buf);
+                       strbuf_release(&err);
+                       *nongit_ok = -1;
+                       return -1;
+               }
+               die("%s", err.buf);
        }
 
-       if (repository_format_version >= 1 && unknown_extensions.nr) {
+       repository_format_precious_objects = candidate.precious_objects;
+       string_list_clear(&candidate.unknown_extensions, 0);
+       if (!has_common) {
+               if (candidate.is_bare != -1) {
+                       is_bare_repository_cfg = candidate.is_bare;
+                       if (is_bare_repository_cfg == 1)
+                               inside_work_tree = -1;
+               }
+               if (candidate.work_tree) {
+                       free(git_work_tree_cfg);
+                       git_work_tree_cfg = candidate.work_tree;
+                       inside_work_tree = -1;
+               }
+       } else {
+               free(candidate.work_tree);
+       }
+
+       return 0;
+}
+
+int read_repository_format(struct repository_format *format, const char *path)
+{
+       memset(format, 0, sizeof(*format));
+       format->version = -1;
+       format->is_bare = -1;
+       string_list_init(&format->unknown_extensions, 1);
+       git_config_from_file(check_repo_format, path, format);
+       return format->version;
+}
+
+int verify_repository_format(const struct repository_format *format,
+                            struct strbuf *err)
+{
+       if (GIT_REPO_VERSION_READ < format->version) {
+               strbuf_addf(err, _("Expected git repo version <= %d, found %d"),
+                           GIT_REPO_VERSION_READ, format->version);
+               return -1;
+       }
+
+       if (format->version >= 1 && format->unknown_extensions.nr) {
                int i;
 
-               if (!nongit_ok)
-                       die("unknown repository extension: %s",
-                           unknown_extensions.items[0].string);
+               strbuf_addstr(err, _("unknown repository extensions found:"));
 
-               for (i = 0; i < unknown_extensions.nr; i++)
-                       warning("unknown repository extension: %s",
-                               unknown_extensions.items[i].string);
-               *nongit_ok = -1;
-               ret = -1;
+               for (i = 0; i < format->unknown_extensions.nr; i++)
+                       strbuf_addf(err, "\n\t%s",
+                                   format->unknown_extensions.items[i].string);
+               return -1;
        }
 
-       strbuf_release(&sb);
-       return ret;
+       return 0;
 }
 
-static void update_linked_gitdir(const char *gitfile, const char *gitdir)
+void read_gitfile_error_die(int error_code, const char *path, const char *dir)
 {
-       struct strbuf path = STRBUF_INIT;
-       struct stat st;
-
-       strbuf_addf(&path, "%s/gitdir", gitdir);
-       if (stat(path.buf, &st) || st.st_mtime + 24 * 3600 < time(NULL))
-               write_file(path.buf, "%s", gitfile);
-       strbuf_release(&path);
+       switch (error_code) {
+       case READ_GITFILE_ERR_STAT_FAILED:
+       case READ_GITFILE_ERR_NOT_A_FILE:
+               /* non-fatal; follow return path */
+               break;
+       case READ_GITFILE_ERR_OPEN_FAILED:
+               die_errno("Error opening '%s'", path);
+       case READ_GITFILE_ERR_TOO_LARGE:
+               die("Too large to be a .git file: '%s'", path);
+       case READ_GITFILE_ERR_READ_FAILED:
+               die("Error reading %s", path);
+       case READ_GITFILE_ERR_INVALID_FORMAT:
+               die("Invalid gitfile format: %s", path);
+       case READ_GITFILE_ERR_NO_PATH:
+               die("No path in gitfile: %s", path);
+       case READ_GITFILE_ERR_NOT_A_REPO:
+               die("Not a git repository: %s", dir);
+       default:
+               die("BUG: unknown error code");
+       }
 }
 
 /*
@@ -469,6 +536,7 @@ const char *read_gitfile_gently(const char *path, int *return_error_code)
        ssize_t len;
 
        if (stat(path, &st)) {
+               /* NEEDSWORK: discern between ENOENT vs other errors */
                error_code = READ_GITFILE_ERR_STAT_FAILED;
                goto cleanup_return;
        }
@@ -485,14 +553,13 @@ const char *read_gitfile_gently(const char *path, int *return_error_code)
                error_code = READ_GITFILE_ERR_OPEN_FAILED;
                goto cleanup_return;
        }
-       buf = xmalloc(st.st_size + 1);
+       buf = xmallocz(st.st_size);
        len = read_in_full(fd, buf, st.st_size);
        close(fd);
        if (len != st.st_size) {
                error_code = READ_GITFILE_ERR_READ_FAILED;
                goto cleanup_return;
        }
-       buf[len] = '\0';
        if (!starts_with(buf, "gitdir: ")) {
                error_code = READ_GITFILE_ERR_INVALID_FORMAT;
                goto cleanup_return;
@@ -508,11 +575,8 @@ const char *read_gitfile_gently(const char *path, int *return_error_code)
 
        if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
                size_t pathlen = slash+1 - path;
-               size_t dirlen = pathlen + len - 8;
-               dir = xmalloc(dirlen + 1);
-               strncpy(dir, path, pathlen);
-               strncpy(dir + pathlen, buf + 8, len - 8);
-               dir[dirlen] = '\0';
+               dir = xstrfmt("%.*s%.*s", (int)pathlen, path,
+                             (int)(len - 8), buf + 8);
                free(buf);
                buf = dir;
        }
@@ -520,34 +584,13 @@ const char *read_gitfile_gently(const char *path, int *return_error_code)
                error_code = READ_GITFILE_ERR_NOT_A_REPO;
                goto cleanup_return;
        }
-       update_linked_gitdir(path, dir);
        path = real_path(dir);
 
 cleanup_return:
        if (return_error_code)
                *return_error_code = error_code;
-       else if (error_code) {
-               switch (error_code) {
-               case READ_GITFILE_ERR_STAT_FAILED:
-               case READ_GITFILE_ERR_NOT_A_FILE:
-                       /* non-fatal; follow return path */
-                       break;
-               case READ_GITFILE_ERR_OPEN_FAILED:
-                       die_errno("Error opening '%s'", path);
-               case READ_GITFILE_ERR_TOO_LARGE:
-                       die("Too large to be a .git file: '%s'", path);
-               case READ_GITFILE_ERR_READ_FAILED:
-                       die("Error reading %s", path);
-               case READ_GITFILE_ERR_INVALID_FORMAT:
-                       die("Invalid gitfile format: %s", path);
-               case READ_GITFILE_ERR_NO_PATH:
-                       die("No path in gitfile: %s", path);
-               case READ_GITFILE_ERR_NOT_A_REPO:
-                       die("Not a git repository: %s", dir);
-               default:
-                       assert(0);
-               }
-       }
+       else if (error_code)
+               read_gitfile_error_die(error_code, path, dir);
 
        free(buf);
        return error_code ? NULL : path;
@@ -660,11 +703,16 @@ static const char *setup_discovered_git_dir(const char *gitdir,
 
        /* --work-tree is set without --git-dir; use discovered one */
        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
+               char *to_free = NULL;
+               const char *ret;
+
                if (offset != cwd->len && !is_absolute_path(gitdir))
-                       gitdir = xstrdup(real_path(gitdir));
+                       gitdir = to_free = real_pathdup(gitdir, 1);
                if (chdir(cwd->buf))
                        die_errno("Could not come back to cwd");
-               return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
+               ret = setup_explicit_git_dir(gitdir, cwd, nongit_ok);
+               free(to_free);
+               return ret;
        }
 
        /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
@@ -684,8 +732,10 @@ static const char *setup_discovered_git_dir(const char *gitdir,
        if (offset == cwd->len)
                return NULL;
 
-       /* Make "offset" point to past the '/', and add a '/' at the end */
-       offset++;
+       /* Make "offset" point past the '/' (already the case for root dirs) */
+       if (offset != offset_1st_component(cwd->buf))
+               offset++;
+       /* Add a '/' at the end */
        strbuf_addch(cwd, '/');
        return cwd->buf + offset;
 }
@@ -703,7 +753,7 @@ static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 
        /* --work-tree is set without --git-dir; use discovered one */
        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
-               const char *gitdir;
+               static const char *gitdir;
 
                gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
                if (chdir(cwd->buf))
@@ -728,9 +778,9 @@ static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 static const char *setup_nongit(const char *cwd, int *nongit_ok)
 {
        if (!nongit_ok)
-               die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
+               die(_("Not a git repository (or any of the parent directories): %s"), DEFAULT_GIT_DIR_ENVIRONMENT);
        if (chdir(cwd))
-               die_errno("Cannot come back to cwd");
+               die_errno(_("Cannot come back to cwd"));
        *nongit_ok = 1;
        return NULL;
 }
@@ -769,59 +819,61 @@ static int canonicalize_ceiling_entry(struct string_list_item *item,
                /* Keep entry but do not canonicalize it */
                return 1;
        } else {
-               const char *real_path = real_path_if_valid(ceil);
-               if (!real_path)
+               char *real_path = real_pathdup(ceil, 0);
+               if (!real_path) {
                        return 0;
+               }
                free(item->string);
-               item->string = xstrdup(real_path);
+               item->string = real_path;
                return 1;
        }
 }
 
+enum discovery_result {
+       GIT_DIR_NONE = 0,
+       GIT_DIR_EXPLICIT,
+       GIT_DIR_DISCOVERED,
+       GIT_DIR_BARE,
+       /* these are errors */
+       GIT_DIR_HIT_CEILING = -1,
+       GIT_DIR_HIT_MOUNT_POINT = -2,
+       GIT_DIR_INVALID_GITFILE = -3
+};
+
 /*
  * We cannot decide in this function whether we are in the work tree or
  * not, since the config can only be read _after_ this function was called.
+ *
+ * Also, we avoid changing any global state (such as the current working
+ * directory) to allow early callers.
+ *
+ * The directory where the search should start needs to be passed in via the
+ * `dir` parameter; upon return, the `dir` buffer will contain the path of
+ * the directory where the search ended, and `gitdir` will contain the path of
+ * the discovered .git/ directory, if any. If `gitdir` is not absolute, it
+ * is relative to `dir` (i.e. *not* necessarily the cwd).
  */
-static const char *setup_git_directory_gently_1(int *nongit_ok)
+static enum discovery_result setup_git_directory_gently_1(struct strbuf *dir,
+                                                         struct strbuf *gitdir,
+                                                         int die_on_error)
 {
        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
        struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
-       static struct strbuf cwd = STRBUF_INIT;
-       const char *gitdirenv, *ret;
-       char *gitfile;
-       int offset, offset_parent, ceil_offset = -1;
+       const char *gitdirenv;
+       int ceil_offset = -1, min_offset = has_dos_drive_prefix(dir->buf) ? 3 : 1;
        dev_t current_device = 0;
        int one_filesystem = 1;
 
-       /*
-        * We may have read an incomplete configuration before
-        * setting-up the git directory. If so, clear the cache so
-        * that the next queries to the configuration reload complete
-        * configuration (including the per-repo config file that we
-        * ignored previously).
-        */
-       git_config_clear();
-
-       /*
-        * Let's assume that we are in a git repository.
-        * If it turns out later that we are somewhere else, the value will be
-        * updated accordingly.
-        */
-       if (nongit_ok)
-               *nongit_ok = 0;
-
-       if (strbuf_getcwd(&cwd))
-               die_errno("Unable to read current working directory");
-       offset = cwd.len;
-
        /*
         * If GIT_DIR is set explicitly, we're not going
         * to do any discovery, but we still do repository
         * validation.
         */
        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
-       if (gitdirenv)
-               return setup_explicit_git_dir(gitdirenv, &cwd, nongit_ok);
+       if (gitdirenv) {
+               strbuf_addstr(gitdir, gitdirenv);
+               return GIT_DIR_EXPLICIT;
+       }
 
        if (env_ceiling_dirs) {
                int empty_entry_found = 0;
@@ -829,15 +881,15 @@ static const char *setup_git_directory_gently_1(int *nongit_ok)
                string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
                filter_string_list(&ceiling_dirs, 0,
                                   canonicalize_ceiling_entry, &empty_entry_found);
-               ceil_offset = longest_ancestor_length(cwd.buf, &ceiling_dirs);
+               ceil_offset = longest_ancestor_length(dir->buf, &ceiling_dirs);
                string_list_clear(&ceiling_dirs, 0);
        }
 
-       if (ceil_offset < 0 && has_dos_drive_prefix(cwd.buf))
-               ceil_offset = 1;
+       if (ceil_offset < 0)
+               ceil_offset = min_offset - 2;
 
        /*
-        * Test in the following order (relative to the cwd):
+        * Test in the following order (relative to the dir):
         * - .git (file containing "gitdir: <path>")
         * - .git/
         * - ./ (bare)
@@ -849,70 +901,170 @@ static const char *setup_git_directory_gently_1(int *nongit_ok)
         */
        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
        if (one_filesystem)
-               current_device = get_device_or_die(".", NULL, 0);
+               current_device = get_device_or_die(dir->buf, NULL, 0);
        for (;;) {
-               gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
-               if (gitfile)
-                       gitdirenv = gitfile = xstrdup(gitfile);
-               else {
-                       if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
-                               gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
+               int offset = dir->len, error_code = 0;
+
+               if (offset > min_offset)
+                       strbuf_addch(dir, '/');
+               strbuf_addstr(dir, DEFAULT_GIT_DIR_ENVIRONMENT);
+               gitdirenv = read_gitfile_gently(dir->buf, die_on_error ?
+                                               NULL : &error_code);
+               if (!gitdirenv) {
+                       if (die_on_error ||
+                           error_code == READ_GITFILE_ERR_NOT_A_FILE) {
+                               /* NEEDSWORK: fail if .git is not file nor dir */
+                               if (is_git_directory(dir->buf))
+                                       gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
+                       } else if (error_code != READ_GITFILE_ERR_STAT_FAILED)
+                               return GIT_DIR_INVALID_GITFILE;
                }
-
+               strbuf_setlen(dir, offset);
                if (gitdirenv) {
-                       ret = setup_discovered_git_dir(gitdirenv,
-                                                      &cwd, offset,
-                                                      nongit_ok);
-                       free(gitfile);
-                       return ret;
+                       strbuf_addstr(gitdir, gitdirenv);
+                       return GIT_DIR_DISCOVERED;
                }
-               free(gitfile);
 
-               if (is_git_directory("."))
-                       return setup_bare_git_dir(&cwd, offset, nongit_ok);
-
-               offset_parent = offset;
-               while (--offset_parent > ceil_offset && cwd.buf[offset_parent] != '/');
-               if (offset_parent <= ceil_offset)
-                       return setup_nongit(cwd.buf, nongit_ok);
-               if (one_filesystem) {
-                       dev_t parent_device = get_device_or_die("..", cwd.buf,
-                                                               offset);
-                       if (parent_device != current_device) {
-                               if (nongit_ok) {
-                                       if (chdir(cwd.buf))
-                                               die_errno("Cannot come back to cwd");
-                                       *nongit_ok = 1;
-                                       return NULL;
-                               }
-                               strbuf_setlen(&cwd, offset);
-                               die("Not a git repository (or any parent up to mount point %s)\n"
-                               "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).",
-                                   cwd.buf);
-                       }
-               }
-               if (chdir("..")) {
-                       strbuf_setlen(&cwd, offset);
-                       die_errno("Cannot change to '%s/..'", cwd.buf);
+               if (is_git_directory(dir->buf)) {
+                       strbuf_addstr(gitdir, ".");
+                       return GIT_DIR_BARE;
                }
-               offset = offset_parent;
+
+               if (offset <= min_offset)
+                       return GIT_DIR_HIT_CEILING;
+
+               while (--offset > ceil_offset && !is_dir_sep(dir->buf[offset]))
+                       ; /* continue */
+               if (offset <= ceil_offset)
+                       return GIT_DIR_HIT_CEILING;
+
+               strbuf_setlen(dir, offset > min_offset ?  offset : min_offset);
+               if (one_filesystem &&
+                   current_device != get_device_or_die(dir->buf, NULL, offset))
+                       return GIT_DIR_HIT_MOUNT_POINT;
+       }
+}
+
+const char *discover_git_directory(struct strbuf *gitdir)
+{
+       struct strbuf dir = STRBUF_INIT, err = STRBUF_INIT;
+       size_t gitdir_offset = gitdir->len, cwd_len;
+       struct repository_format candidate;
+
+       if (strbuf_getcwd(&dir))
+               return NULL;
+
+       cwd_len = dir.len;
+       if (setup_git_directory_gently_1(&dir, gitdir, 0) <= 0) {
+               strbuf_release(&dir);
+               return NULL;
        }
+
+       /*
+        * The returned gitdir is relative to dir, and if dir does not reflect
+        * the current working directory, we simply make the gitdir absolute.
+        */
+       if (dir.len < cwd_len && !is_absolute_path(gitdir->buf + gitdir_offset)) {
+               /* Avoid a trailing "/." */
+               if (!strcmp(".", gitdir->buf + gitdir_offset))
+                       strbuf_setlen(gitdir, gitdir_offset);
+               else
+                       strbuf_addch(&dir, '/');
+               strbuf_insert(gitdir, gitdir_offset, dir.buf, dir.len);
+       }
+
+       strbuf_reset(&dir);
+       strbuf_addf(&dir, "%s/config", gitdir->buf + gitdir_offset);
+       read_repository_format(&candidate, dir.buf);
+       strbuf_release(&dir);
+
+       if (verify_repository_format(&candidate, &err) < 0) {
+               warning("ignoring git dir '%s': %s",
+                       gitdir->buf + gitdir_offset, err.buf);
+               strbuf_release(&err);
+               return NULL;
+       }
+
+       return gitdir->buf + gitdir_offset;
 }
 
 const char *setup_git_directory_gently(int *nongit_ok)
 {
-       const char *prefix;
+       static struct strbuf cwd = STRBUF_INIT;
+       struct strbuf dir = STRBUF_INIT, gitdir = STRBUF_INIT;
+       const char *prefix, *env_prefix;
+
+       /*
+        * We may have read an incomplete configuration before
+        * setting-up the git directory. If so, clear the cache so
+        * that the next queries to the configuration reload complete
+        * configuration (including the per-repo config file that we
+        * ignored previously).
+        */
+       git_config_clear();
+
+       /*
+        * Let's assume that we are in a git repository.
+        * If it turns out later that we are somewhere else, the value will be
+        * updated accordingly.
+        */
+       if (nongit_ok)
+               *nongit_ok = 0;
+
+       if (strbuf_getcwd(&cwd))
+               die_errno(_("Unable to read current working directory"));
+       strbuf_addbuf(&dir, &cwd);
+
+       switch (setup_git_directory_gently_1(&dir, &gitdir, 1)) {
+       case GIT_DIR_NONE:
+               prefix = NULL;
+               break;
+       case GIT_DIR_EXPLICIT:
+               prefix = setup_explicit_git_dir(gitdir.buf, &cwd, nongit_ok);
+               break;
+       case GIT_DIR_DISCOVERED:
+               if (dir.len < cwd.len && chdir(dir.buf))
+                       die(_("Cannot change to '%s'"), dir.buf);
+               prefix = setup_discovered_git_dir(gitdir.buf, &cwd, dir.len,
+                                                 nongit_ok);
+               break;
+       case GIT_DIR_BARE:
+               if (dir.len < cwd.len && chdir(dir.buf))
+                       die(_("Cannot change to '%s'"), dir.buf);
+               prefix = setup_bare_git_dir(&cwd, dir.len, nongit_ok);
+               break;
+       case GIT_DIR_HIT_CEILING:
+               prefix = setup_nongit(cwd.buf, nongit_ok);
+               break;
+       case GIT_DIR_HIT_MOUNT_POINT:
+               if (nongit_ok) {
+                       *nongit_ok = 1;
+                       strbuf_release(&cwd);
+                       strbuf_release(&dir);
+                       return NULL;
+               }
+               die(_("Not a git repository (or any parent up to mount point %s)\n"
+                     "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
+                   dir.buf);
+       default:
+               die("BUG: unhandled setup_git_directory_1() result");
+       }
+
+       env_prefix = getenv(GIT_TOPLEVEL_PREFIX_ENVIRONMENT);
+       if (env_prefix)
+               prefix = env_prefix;
 
-       prefix = setup_git_directory_gently_1(nongit_ok);
        if (prefix)
                setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
        else
                setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
 
-       if (startup_info) {
-               startup_info->have_repository = !nongit_ok || !*nongit_ok;
-               startup_info->prefix = prefix;
-       }
+       startup_info->have_repository = !nongit_ok || !*nongit_ok;
+       startup_info->prefix = prefix;
+
+       strbuf_release(&dir);
+       strbuf_release(&gitdir);
+
        return prefix;
 }
 
@@ -956,9 +1108,9 @@ int git_config_perm(const char *var, const char *value)
        /* A filemode value was given: 0xxx */
 
        if ((i & 0600) != 0600)
-               die("Problem with core.sharedRepository filemode value "
+               die(_("Problem with core.sharedRepository filemode value "
                    "(0%.3o).\nThe owner of files must always have "
-                   "read and write permissions.", i);
+                   "read and write permissions."), i);
 
        /*
         * Mask filemode value. Others can not get write permission.
@@ -967,28 +1119,10 @@ int git_config_perm(const char *var, const char *value)
        return -(i & 0666);
 }
 
-int check_repository_format_version(const char *var, const char *value, void *cb)
-{
-       int ret = check_repo_format(var, value, cb);
-       if (ret)
-               return ret;
-       if (strcmp(var, "core.bare") == 0) {
-               is_bare_repository_cfg = git_config_bool(var, value);
-               if (is_bare_repository_cfg == 1)
-                       inside_work_tree = -1;
-       } else if (strcmp(var, "core.worktree") == 0) {
-               if (!value)
-                       return config_error_nonbool(var);
-               free(git_work_tree_cfg);
-               git_work_tree_cfg = xstrdup(value);
-               inside_work_tree = -1;
-       }
-       return 0;
-}
-
-int check_repository_format(void)
+void check_repository_format(void)
 {
-       return check_repository_format_gently(get_git_dir(), NULL);
+       check_repository_format_gently(get_git_dir(), NULL);
+       startup_info->have_repository = 1;
 }
 
 /*
@@ -1002,11 +1136,11 @@ const char *setup_git_directory(void)
        return setup_git_directory_gently(NULL);
 }
 
-const char *resolve_gitdir(const char *suspect)
+const char *resolve_gitdir_gently(const char *suspect, int *return_error_code)
 {
        if (is_git_directory(suspect))
                return suspect;
-       return read_gitfile(suspect);
+       return read_gitfile_gently(suspect, return_error_code);
 }
 
 /* if any standard file descriptor is missing open it to /dev/null */