1 files changed, 119 insertions, 15 deletions

diff --git a/third_party/git/builtin/init-db.c b/third_party/git/builtin/init-db.c
index 944ec77fe103..01bc648d416f 100644
--- a/third_party/git/builtin/init-db.c
+++ b/third_party/git/builtin/init-db.c
@@ -9,6 +9,7 @@
 #include "builtin.h"
 #include "exec-cmd.h"
 #include "parse-options.h"
+#include "worktree.h"
 
 #ifndef DEFAULT_GIT_TEMPLATE_DIR
 #define DEFAULT_GIT_TEMPLATE_DIR "/usr/share/git-core/templates"
@@ -20,6 +21,8 @@
 #define TEST_FILEMODE 1
 #endif
 
+#define GIT_DEFAULT_HASH_ENVIRONMENT "GIT_DEFAULT_HASH"
+
 static int init_is_bare_repository = 0;
 static int init_shared_repository = -1;
 static const char *init_db_template_dir;
@@ -176,13 +179,34 @@ static int needs_work_tree_config(const char *git_dir, const char *work_tree)
 	return 1;
 }
 
+void initialize_repository_version(int hash_algo, int reinit)
+{
+	char repo_version_string[10];
+	int repo_version = GIT_REPO_VERSION;
+
+	if (hash_algo != GIT_HASH_SHA1)
+		repo_version = GIT_REPO_VERSION_READ;
+
+	/* This forces creation of new config file */
+	xsnprintf(repo_version_string, sizeof(repo_version_string),
+		  "%d", repo_version);
+	git_config_set("core.repositoryformatversion", repo_version_string);
+
+	if (hash_algo != GIT_HASH_SHA1)
+		git_config_set("extensions.objectformat",
+			       hash_algos[hash_algo].name);
+	else if (reinit)
+		git_config_set_gently("extensions.objectformat", NULL);
+}
+
 static int create_default_files(const char *template_path,
-				const char *original_git_dir)
+				const char *original_git_dir,
+				const char *initial_branch,
+				const struct repository_format *fmt)
 {
 	struct stat st1;
 	struct strbuf buf = STRBUF_INIT;
 	char *path;
-	char repo_version_string[10];
 	char junk[2];
 	int reinit;
 	int filemode;
@@ -233,21 +257,29 @@ static int create_default_files(const char *template_path,
 		die("failed to set up refs db: %s", err.buf);
 
 	/*
-	 * Create the default symlink from ".git/HEAD" to the "master"
-	 * branch, if it does not exist yet.
+	 * 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) {
-		if (create_symref("HEAD", "refs/heads/master", NULL) < 0)
+		char *ref;
+
+		if (!initial_branch)
+			initial_branch = git_default_branch_name();
+
+		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);
 	}
 
-	/* This forces creation of new config file */
-	xsnprintf(repo_version_string, sizeof(repo_version_string),
-		  "%d", GIT_REPO_VERSION);
-	git_config_set("core.repositoryformatversion", repo_version_string);
+	initialize_repository_version(fmt->hash_algo, 0);
 
 	/* Check filemode trustability */
 	path = git_path_buf(&buf, "config");
@@ -335,17 +367,40 @@ static void separate_git_dir(const char *git_dir, const char *git_link)
 
 		if (rename(src, git_dir))
 			die_errno(_("unable to move %s to %s"), src, git_dir);
+		repair_worktrees(NULL, NULL);
 	}
 
 	write_file(git_link, "gitdir: %s", git_dir);
 }
 
+static void validate_hash_algorithm(struct repository_format *repo_fmt, int hash)
+{
+	const char *env = getenv(GIT_DEFAULT_HASH_ENVIRONMENT);
+	/*
+	 * If we already have an initialized repo, don't allow the user to
+	 * specify a different algorithm, as that could cause corruption.
+	 * Otherwise, if the user has specified one on the command line, use it.
+	 */
+	if (repo_fmt->version >= 0 && hash != GIT_HASH_UNKNOWN && hash != repo_fmt->hash_algo)
+		die(_("attempt to reinitialize repository with different hash"));
+	else if (hash != GIT_HASH_UNKNOWN)
+		repo_fmt->hash_algo = hash;
+	else if (env) {
+		int env_algo = hash_algo_by_name(env);
+		if (env_algo == GIT_HASH_UNKNOWN)
+			die(_("unknown hash algorithm '%s'"), env);
+		repo_fmt->hash_algo = env_algo;
+	}
+}
+
 int init_db(const char *git_dir, const char *real_git_dir,
-	    const char *template_dir, unsigned int flags)
+	    const char *template_dir, int hash, const char *initial_branch,
+	    unsigned int flags)
 {
 	int reinit;
 	int exist_ok = flags & INIT_DB_EXIST_OK;
 	char *original_git_dir = real_pathdup(git_dir, 1);
+	struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
 
 	if (real_git_dir) {
 		struct stat st;
@@ -356,12 +411,12 @@ int init_db(const char *git_dir, const char *real_git_dir,
 		if (!exist_ok && !stat(real_git_dir, &st))
 			die(_("%s already exists"), real_git_dir);
 
-		set_git_dir(real_path(real_git_dir));
+		set_git_dir(real_git_dir, 1);
 		git_dir = get_git_dir();
 		separate_git_dir(git_dir, original_git_dir);
 	}
 	else {
-		set_git_dir(real_path(git_dir));
+		set_git_dir(git_dir, 1);
 		git_dir = get_git_dir();
 	}
 	startup_info->have_repository = 1;
@@ -378,9 +433,15 @@ int init_db(const char *git_dir, const char *real_git_dir,
 	 * config file, so this will not fail.  What we are catching
 	 * is an attempt to reinitialize new repository with an old tool.
 	 */
-	check_repository_format();
+	check_repository_format(&repo_fmt);
 
-	reinit = create_default_files(template_dir, original_git_dir);
+	validate_hash_algorithm(&repo_fmt, hash);
+
+	reinit = create_default_files(template_dir, original_git_dir,
+				      initial_branch, &repo_fmt);
+	if (reinit && initial_branch)
+		warning(_("re-init: ignored --initial-branch=%s"),
+			initial_branch);
 
 	create_object_directory();
 
@@ -482,6 +543,9 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 	const char *work_tree;
 	const char *template_dir = NULL;
 	unsigned int flags = 0;
+	const char *object_format = NULL;
+	const char *initial_branch = NULL;
+	int hash_algo = GIT_HASH_UNKNOWN;
 	const struct option init_db_options[] = {
 		OPT_STRING(0, "template", &template_dir, N_("template-directory"),
 				N_("directory from which templates will be used")),
@@ -494,11 +558,18 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 		OPT_BIT('q', "quiet", &flags, N_("be quiet"), INIT_DB_QUIET),
 		OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
 			   N_("separate git dir from working tree")),
+		OPT_STRING('b', "initial-branch", &initial_branch, N_("name"),
+			   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_END()
 	};
 
 	argc = parse_options(argc, argv, prefix, init_db_options, init_db_usage, 0);
 
+	if (real_git_dir && is_bare_repository_cfg == 1)
+		die(_("--separate-git-dir and --bare are mutually exclusive"));
+
 	if (real_git_dir && !is_absolute_path(real_git_dir))
 		real_git_dir = real_pathdup(real_git_dir, 1);
 
@@ -546,6 +617,12 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 		free(cwd);
 	}
 
+	if (object_format) {
+		hash_algo = hash_algo_by_name(object_format);
+		if (hash_algo == GIT_HASH_UNKNOWN)
+			die(_("unknown hash algorithm '%s'"), object_format);
+	}
+
 	if (init_shared_repository != -1)
 		set_shared_repository(init_shared_repository);
 
@@ -567,6 +644,30 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 	if (!git_dir)
 		git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 
+	/*
+	 * When --separate-git-dir is used inside a linked worktree, take
+	 * care to ensure that the common .git/ directory is relocated, not
+	 * the worktree-specific .git/worktrees/<id>/ directory.
+	 */
+	if (real_git_dir) {
+		int err;
+		const char *p;
+		struct strbuf sb = STRBUF_INIT;
+
+		p = read_gitfile_gently(git_dir, &err);
+		if (p && get_common_dir(&sb, p)) {
+			struct strbuf mainwt = STRBUF_INIT;
+
+			strbuf_addbuf(&mainwt, &sb);
+			strbuf_strip_suffix(&mainwt, "/.git");
+			if (chdir(mainwt.buf) < 0)
+				die_errno(_("cannot chdir to %s"), mainwt.buf);
+			strbuf_release(&mainwt);
+			git_dir = strbuf_detach(&sb, NULL);
+		}
+		strbuf_release(&sb);
+	}
+
 	if (is_bare_repository_cfg < 0)
 		is_bare_repository_cfg = guess_repository_type(git_dir);
 
@@ -588,6 +689,8 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 				   get_git_work_tree());
 	}
 	else {
+		if (real_git_dir)
+			die(_("--separate-git-dir incompatible with bare repository"));
 		if (work_tree)
 			set_git_work_tree(work_tree);
 	}
@@ -597,5 +700,6 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 	UNLEAK(work_tree);
 
 	flags |= INIT_DB_EXIST_OK;
-	return init_db(git_dir, real_git_dir, template_dir, flags);
+	return init_db(git_dir, real_git_dir, template_dir, hash_algo,
+		       initial_branch, flags);
 }