Merge branch 'ps/refstorage-extension'

Introduce a new extension "refstorage" so that we can mark a
repository that uses a non-default ref backend, like reftable.

* ps/refstorage-extension:
  t9500: write "extensions.refstorage" into config
  builtin/clone: introduce `--ref-format=` value flag
  builtin/init: introduce `--ref-format=` value flag
  builtin/rev-parse: introduce `--show-ref-format` flag
  t: introduce GIT_TEST_DEFAULT_REF_FORMAT envvar
  setup: introduce GIT_DEFAULT_REF_FORMAT envvar
  setup: introduce "extensions.refStorage" extension
  setup: set repository's formats on init
  setup: start tracking ref storage format
  refs: refactor logic to look up storage backends
  worktree: skip reading HEAD when repairing worktrees
  t: introduce DEFAULT_REPO_FORMAT prereq

1 files changed, 15 insertions, 1 deletions

diff --git a/builtin/init-db.c b/builtin/init-db.c
index b89814a6f8..0170469b84 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -10,6 +10,8 @@
 #include "object-file.h"
 #include "parse-options.h"
 #include "path.h"
+#include "refs.h"
+#include "repository.h"
 #include "setup.h"
 #include "strbuf.h"
 
@@ -56,6 +58,7 @@ static int shared_callback(const struct option *opt, const char *arg, int unset)
 static const char *const init_db_usage[] = {
 	N_("git init [-q | --quiet] [--bare] [--template=<template-directory>]\n"
 	   "         [--separate-git-dir <git-dir>] [--object-format=<format>]\n"
+	   "         [--ref-format=<format>]\n"
 	   "         [-b <branch-name> | --initial-branch=<branch-name>]\n"
 	   "         [--shared[=<permissions>]] [<directory>]"),
 	NULL
@@ -75,8 +78,10 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 	const char *template_dir = NULL;
 	unsigned int flags = 0;
 	const char *object_format = NULL;
+	const char *ref_format = NULL;
 	const char *initial_branch = NULL;
 	int hash_algo = GIT_HASH_UNKNOWN;
+	unsigned int ref_storage_format = REF_STORAGE_FORMAT_UNKNOWN;
 	int init_shared_repository = -1;
 	const struct option init_db_options[] = {
 		OPT_STRING(0, "template", &template_dir, N_("template-directory"),
@@ -94,6 +99,8 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 			   N_("override the name of the initial branch")),
 		OPT_STRING(0, "object-format", &object_format, N_("hash"),
 			   N_("specify the hash algorithm to use")),
+		OPT_STRING(0, "ref-format", &ref_format, N_("format"),
+			   N_("specify the reference format to use")),
 		OPT_END()
 	};
 
@@ -157,6 +164,12 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 			die(_("unknown hash algorithm '%s'"), object_format);
 	}
 
+	if (ref_format) {
+		ref_storage_format = ref_storage_format_by_name(ref_format);
+		if (ref_storage_format == REF_STORAGE_FORMAT_UNKNOWN)
+			die(_("unknown ref storage format '%s'"), ref_format);
+	}
+
 	if (init_shared_repository != -1)
 		set_shared_repository(init_shared_repository);
 
@@ -235,5 +248,6 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 
 	flags |= INIT_DB_EXIST_OK;
 	return init_db(git_dir, real_git_dir, template_dir, hash_algo,
-		       initial_branch, init_shared_repository, flags);
+		       ref_storage_format, initial_branch,
+		       init_shared_repository, flags);
 }