setup: extract function to create the refdb

We're about to let callers skip creation of the reference database when
calling `init_db()`. Extract the logic into a standalone function so
that it becomes easier to do this refactoring.

While at it, expand the comment that explains why we always create the
"refs/" directory.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/setup.c b/setup.c
index fc592dc6dd5bf3f2ac7ac01ca0d72b7ce0129e77..865cfe6743e2dd819bec4043645c7cac17c69f69 100644 (file)
--- a/setup.c
+++ b/setup.c
@@ -1885,6 +1885,68 @@ void initialize_repository_version(int hash_algo, int reinit)
                git_config_set_gently("extensions.objectformat", NULL);
 }
 
+static int is_reinit(void)
+{
+       struct strbuf buf = STRBUF_INIT;
+       char junk[2];
+       int ret;
+
+       git_path_buf(&buf, "HEAD");
+       ret = !access(buf.buf, R_OK) || readlink(buf.buf, junk, sizeof(junk) - 1) != -1;
+       strbuf_release(&buf);
+       return ret;
+}
+
+static void create_reference_database(const char *initial_branch, int quiet)
+{
+       struct strbuf err = STRBUF_INIT;
+       int reinit = is_reinit();
+
+       /*
+        * We need to create a "refs" dir in any case so that older versions of
+        * Git can tell that this is a repository. This serves two main purposes:
+        *
+        * - Clients will know to stop walking the parent-directory chain when
+        *   detecting the Git repository. Otherwise they may end up detecting
+        *   a Git repository in a parent directory instead.
+        *
+        * - Instead of failing to detect a repository with unknown reference
+        *   format altogether, old clients will print an error saying that
+        *   they do not understand the reference format extension.
+        */
+       safe_create_dir(git_path("refs"), 1);
+       adjust_shared_perm(git_path("refs"));
+
+       if (refs_init_db(&err))
+               die("failed to set up refs db: %s", err.buf);
+
+       /*
+        * Point the HEAD symref to the initial branch with if HEAD does
+        * not yet exist.
+        */
+       if (!reinit) {
+               char *ref;
+
+               if (!initial_branch)
+                       initial_branch = git_default_branch_name(quiet);
+
+               ref = xstrfmt("refs/heads/%s", initial_branch);
+               if (check_refname_format(ref, 0) < 0)
+                       die(_("invalid initial branch name: '%s'"),
+                           initial_branch);
+
+               if (create_symref("HEAD", ref, NULL) < 0)
+                       exit(1);
+               free(ref);
+       }
+
+       if (reinit && initial_branch)
+               warning(_("re-init: ignored --initial-branch=%s"),
+                       initial_branch);
+
+       strbuf_release(&err);
+}
+
 static int create_default_files(const char *template_path,
                                const char *original_git_dir,
                                const char *initial_branch,
@@ -1896,10 +1958,8 @@ static int create_default_files(const char *template_path,
        struct stat st1;
        struct strbuf buf = STRBUF_INIT;
        char *path;
-       char junk[2];
        int reinit;
        int filemode;
-       struct strbuf err = STRBUF_INIT;
        const char *init_template_dir = NULL;
        const char *work_tree = get_git_work_tree();
 
@@ -1919,6 +1979,8 @@ static int create_default_files(const char *template_path,
        reset_shared_repository();
        git_config(git_default_config, NULL);
 
+       reinit = is_reinit();
+
        /*
         * We must make sure command-line options continue to override any
         * values we might have just re-read from the config.
@@ -1962,39 +2024,7 @@ static int create_default_files(const char *template_path,
                adjust_shared_perm(get_git_dir());
        }
 
-       /*
-        * We need to create a "refs" dir in any case so that older
-        * versions of git can tell that this is a repository.
-        */
-       safe_create_dir(git_path("refs"), 1);
-       adjust_shared_perm(git_path("refs"));
-
-       if (refs_init_db(&err))
-               die("failed to set up refs db: %s", err.buf);
-
-       /*
-        * Point the HEAD symref to the initial branch with if HEAD does
-        * not yet exist.
-        */
-       path = git_path_buf(&buf, "HEAD");
-       reinit = (!access(path, R_OK)
-                 || readlink(path, junk, sizeof(junk)-1) != -1);
-       if (!reinit) {
-               char *ref;
-
-               if (!initial_branch)
-                       initial_branch = git_default_branch_name(quiet);
-
-               ref = xstrfmt("refs/heads/%s", initial_branch);
-               if (check_refname_format(ref, 0) < 0)
-                       die(_("invalid initial branch name: '%s'"),
-                           initial_branch);
-
-               if (create_symref("HEAD", ref, NULL) < 0)
-                       exit(1);
-               free(ref);
-       }
-
+       create_reference_database(initial_branch, quiet);
        initialize_repository_version(fmt->hash_algo, 0);
 
        /* Check filemode trustability */
@@ -2158,9 +2188,6 @@ int init_db(const char *git_dir, const char *real_git_dir,
                                      prev_bare_repository,
                                      init_shared_repository,
                                      flags & INIT_DB_QUIET);
-       if (reinit && initial_branch)
-               warning(_("re-init: ignored --initial-branch=%s"),
-                       initial_branch);
 
        create_object_directory();