1 files changed, 176 insertions, 45 deletions

diff --git a/builtin/worktree.c b/builtin/worktree.c
index 6a264ee749..475b9581a5 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -3,16 +3,28 @@
 #include "dir.h"
 #include "parse-options.h"
 #include "argv-array.h"
+#include "branch.h"
+#include "refs.h"
 #include "run-command.h"
 #include "sigchain.h"
 #include "refs.h"
+#include "utf8.h"
+#include "worktree.h"
 
 static const char * const worktree_usage[] = {
-	N_("git worktree add [<options>] <path> <branch>"),
+	N_("git worktree add [<options>] <path> [<branch>]"),
 	N_("git worktree prune [<options>]"),
+	N_("git worktree list [<options>]"),
 	NULL
 };
 
+struct add_opts {
+	int force;
+	int detach;
+	const char *new_branch;
+	int force_new_branch;
+};
+
 static int show_only;
 static int verbose;
 static unsigned long expire;
@@ -172,19 +184,35 @@ static const char *worktree_basename(const char *path, int *olen)
 	return name;
 }
 
-static int add_worktree(const char *path, const char **child_argv)
+static int add_worktree(const char *path, const char *refname,
+			const struct add_opts *opts)
 {
 	struct strbuf sb_git = STRBUF_INIT, sb_repo = STRBUF_INIT;
 	struct strbuf sb = STRBUF_INIT;
 	const char *name;
 	struct stat st;
 	struct child_process cp;
+	struct argv_array child_env = ARGV_ARRAY_INIT;
 	int counter = 0, len, ret;
-	unsigned char rev[20];
+	struct strbuf symref = STRBUF_INIT;
+	struct commit *commit = NULL;
 
 	if (file_exists(path) && !is_empty_dir(path))
 		die(_("'%s' already exists"), path);
 
+	/* is 'refname' a branch or commit? */
+	if (opts->force_new_branch) /* definitely a branch */
+		;
+	else if (!opts->detach && !strbuf_check_branch_ref(&symref, refname) &&
+		 ref_exists(symref.buf)) { /* it's a branch */
+		if (!opts->force)
+			die_if_checked_out(symref.buf);
+	} else { /* must be a commit */
+		commit = lookup_commit_reference_by_name(refname);
+		if (!commit)
+			die(_("invalid reference: %s"), refname);
+	}
+
 	name = worktree_basename(path, &len);
 	strbuf_addstr(&sb_repo,
 		      git_path("worktrees/%.*s", (int)(path + len - name), name));
@@ -213,7 +241,7 @@ static int add_worktree(const char *path, const char **child_argv)
 	 * after the preparation is over.
 	 */
 	strbuf_addf(&sb, "%s/locked", sb_repo.buf);
-	write_file(sb.buf, 1, "initializing\n");
+	write_file(sb.buf, "initializing");
 
 	strbuf_addf(&sb_git, "%s/.git", path);
 	if (safe_create_leading_directories_const(sb_git.buf))
@@ -223,37 +251,45 @@ static int add_worktree(const char *path, const char **child_argv)
 
 	strbuf_reset(&sb);
 	strbuf_addf(&sb, "%s/gitdir", sb_repo.buf);
-	write_file(sb.buf, 1, "%s\n", real_path(sb_git.buf));
-	write_file(sb_git.buf, 1, "gitdir: %s/worktrees/%s\n",
+	write_file(sb.buf, "%s", real_path(sb_git.buf));
+	write_file(sb_git.buf, "gitdir: %s/worktrees/%s",
 		   real_path(get_git_common_dir()), name);
 	/*
 	 * This is to keep resolve_ref() happy. We need a valid HEAD
-	 * or is_git_directory() will reject the directory. Moreover, HEAD
-	 * in the new worktree must resolve to the same value as HEAD in
-	 * the current tree since the command invoked to populate the new
-	 * worktree will be handed the branch/ref specified by the user.
-	 * For instance, if the user asks for the new worktree to be based
-	 * at HEAD~5, then the resolved HEAD~5 in the new worktree must
-	 * match the resolved HEAD~5 in the current tree in order to match
-	 * the user's expectation.
+	 * or is_git_directory() will reject the directory. Any value which
+	 * looks like an object ID will do since it will be immediately
+	 * replaced by the symbolic-ref or update-ref invocation in the new
+	 * worktree.
 	 */
-	if (!resolve_ref_unsafe("HEAD", 0, rev, NULL))
-		die(_("unable to resolve HEAD"));
 	strbuf_reset(&sb);
 	strbuf_addf(&sb, "%s/HEAD", sb_repo.buf);
-	write_file(sb.buf, 1, "%s\n", sha1_to_hex(rev));
+	write_file(sb.buf, "0000000000000000000000000000000000000000");
 	strbuf_reset(&sb);
 	strbuf_addf(&sb, "%s/commondir", sb_repo.buf);
-	write_file(sb.buf, 1, "../..\n");
+	write_file(sb.buf, "../..");
 
-	fprintf_ln(stderr, _("Enter %s (identifier %s)"), path, name);
+	fprintf_ln(stderr, _("Preparing %s (identifier %s)"), path, name);
 
-	setenv("GIT_CHECKOUT_NEW_WORKTREE", "1", 1);
-	setenv(GIT_DIR_ENVIRONMENT, sb_git.buf, 1);
-	setenv(GIT_WORK_TREE_ENVIRONMENT, path, 1);
+	argv_array_pushf(&child_env, "%s=%s", GIT_DIR_ENVIRONMENT, sb_git.buf);
+	argv_array_pushf(&child_env, "%s=%s", GIT_WORK_TREE_ENVIRONMENT, path);
 	memset(&cp, 0, sizeof(cp));
 	cp.git_cmd = 1;
-	cp.argv = child_argv;
+
+	if (commit)
+		argv_array_pushl(&cp.args, "update-ref", "HEAD",
+				 oid_to_hex(&commit->object.oid), NULL);
+	else
+		argv_array_pushl(&cp.args, "symbolic-ref", "HEAD",
+				 symref.buf, NULL);
+	cp.env = child_env.argv;
+	ret = run_command(&cp);
+	if (ret)
+		goto done;
+
+	cp.argv = NULL;
+	argv_array_clear(&cp.args);
+	argv_array_pushl(&cp.args, "reset", "--hard", NULL);
+	cp.env = child_env.argv;
 	ret = run_command(&cp);
 	if (!ret) {
 		is_junk = 0;
@@ -262,10 +298,13 @@ static int add_worktree(const char *path, const char **child_argv)
 		junk_work_tree = NULL;
 		junk_git_dir = NULL;
 	}
+done:
 	strbuf_reset(&sb);
 	strbuf_addf(&sb, "%s/locked", sb_repo.buf);
 	unlink_or_warn(sb.buf);
+	argv_array_clear(&child_env);
 	strbuf_release(&sb);
+	strbuf_release(&symref);
 	strbuf_release(&sb_repo);
 	strbuf_release(&sb_git);
 	return ret;
@@ -273,47 +312,137 @@ static int add_worktree(const char *path, const char **child_argv)
 
 static int add(int ac, const char **av, const char *prefix)
 {
-	int force = 0, detach = 0;
-	const char *new_branch = NULL, *new_branch_force = NULL;
+	struct add_opts opts;
+	const char *new_branch_force = NULL;
 	const char *path, *branch;
-	struct argv_array cmd = ARGV_ARRAY_INIT;
 	struct option options[] = {
-		OPT__FORCE(&force, N_("checkout <branch> even if already checked out in other worktree")),
-		OPT_STRING('b', NULL, &new_branch, N_("branch"),
+		OPT__FORCE(&opts.force, N_("checkout <branch> even if already checked out in other worktree")),
+		OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
 			   N_("create a new branch")),
 		OPT_STRING('B', NULL, &new_branch_force, N_("branch"),
 			   N_("create or reset a branch")),
-		OPT_BOOL(0, "detach", &detach, N_("detach HEAD at named commit")),
+		OPT_BOOL(0, "detach", &opts.detach, N_("detach HEAD at named commit")),
 		OPT_END()
 	};
 
+	memset(&opts, 0, sizeof(opts));
 	ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
-	if (new_branch && new_branch_force)
-		die(_("-b and -B are mutually exclusive"));
+	if (!!opts.detach + !!opts.new_branch + !!new_branch_force > 1)
+		die(_("-b, -B, and --detach are mutually exclusive"));
 	if (ac < 1 || ac > 2)
 		usage_with_options(worktree_usage, options);
 
 	path = prefix ? prefix_filename(prefix, strlen(prefix), av[0]) : av[0];
 	branch = ac < 2 ? "HEAD" : av[1];
 
-	if (ac < 2 && !new_branch && !new_branch_force) {
+	opts.force_new_branch = !!new_branch_force;
+	if (opts.force_new_branch)
+		opts.new_branch = new_branch_force;
+
+	if (ac < 2 && !opts.new_branch && !opts.detach) {
 		int n;
 		const char *s = worktree_basename(path, &n);
-		new_branch = xstrndup(s, n);
+		opts.new_branch = xstrndup(s, n);
+	}
+
+	if (opts.new_branch) {
+		struct child_process cp;
+		memset(&cp, 0, sizeof(cp));
+		cp.git_cmd = 1;
+		argv_array_push(&cp.args, "branch");
+		if (opts.force_new_branch)
+			argv_array_push(&cp.args, "--force");
+		argv_array_push(&cp.args, opts.new_branch);
+		argv_array_push(&cp.args, branch);
+		if (run_command(&cp))
+			return -1;
+		branch = opts.new_branch;
+	}
+
+	return add_worktree(path, branch, &opts);
+}
+
+static void show_worktree_porcelain(struct worktree *wt)
+{
+	printf("worktree %s\n", wt->path);
+	if (wt->is_bare)
+		printf("bare\n");
+	else {
+		printf("HEAD %s\n", sha1_to_hex(wt->head_sha1));
+		if (wt->is_detached)
+			printf("detached\n");
+		else
+			printf("branch %s\n", wt->head_ref);
+	}
+	printf("\n");
+}
+
+static void show_worktree(struct worktree *wt, int path_maxlen, int abbrev_len)
+{
+	struct strbuf sb = STRBUF_INIT;
+	int cur_path_len = strlen(wt->path);
+	int path_adj = cur_path_len - utf8_strwidth(wt->path);
+
+	strbuf_addf(&sb, "%-*s ", 1 + path_maxlen + path_adj, wt->path);
+	if (wt->is_bare)
+		strbuf_addstr(&sb, "(bare)");
+	else {
+		strbuf_addf(&sb, "%-*s ", abbrev_len,
+				find_unique_abbrev(wt->head_sha1, DEFAULT_ABBREV));
+		if (!wt->is_detached)
+			strbuf_addf(&sb, "[%s]", shorten_unambiguous_ref(wt->head_ref, 0));
+		else
+			strbuf_addstr(&sb, "(detached HEAD)");
 	}
+	printf("%s\n", sb.buf);
 
-	argv_array_push(&cmd, "checkout");
-	if (force)
-		argv_array_push(&cmd, "--ignore-other-worktrees");
-	if (new_branch)
-		argv_array_pushl(&cmd, "-b", new_branch, NULL);
-	if (new_branch_force)
-		argv_array_pushl(&cmd, "-B", new_branch_force, NULL);
-	if (detach)
-		argv_array_push(&cmd, "--detach");
-	argv_array_push(&cmd, branch);
-
-	return add_worktree(path, cmd.argv);
+	strbuf_release(&sb);
+}
+
+static void measure_widths(struct worktree **wt, int *abbrev, int *maxlen)
+{
+	int i;
+
+	for (i = 0; wt[i]; i++) {
+		int sha1_len;
+		int path_len = strlen(wt[i]->path);
+
+		if (path_len > *maxlen)
+			*maxlen = path_len;
+		sha1_len = strlen(find_unique_abbrev(wt[i]->head_sha1, *abbrev));
+		if (sha1_len > *abbrev)
+			*abbrev = sha1_len;
+	}
+}
+
+static int list(int ac, const char **av, const char *prefix)
+{
+	int porcelain = 0;
+
+	struct option options[] = {
+		OPT_BOOL(0, "porcelain", &porcelain, N_("machine-readable output")),
+		OPT_END()
+	};
+
+	ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
+	if (ac)
+		usage_with_options(worktree_usage, options);
+	else {
+		struct worktree **worktrees = get_worktrees();
+		int path_maxlen = 0, abbrev = DEFAULT_ABBREV, i;
+
+		if (!porcelain)
+			measure_widths(worktrees, &abbrev, &path_maxlen);
+
+		for (i = 0; worktrees[i]; i++) {
+			if (porcelain)
+				show_worktree_porcelain(worktrees[i]);
+			else
+				show_worktree(worktrees[i], path_maxlen, abbrev);
+		}
+		free_worktrees(worktrees);
+	}
+	return 0;
 }
 
 int cmd_worktree(int ac, const char **av, const char *prefix)
@@ -328,5 +457,7 @@ int cmd_worktree(int ac, const char **av, const char *prefix)
 		return add(ac - 1, av + 1, prefix);
 	if (!strcmp(av[1], "prune"))
 		return prune(ac - 1, av + 1, prefix);
+	if (!strcmp(av[1], "list"))
+		return list(ac - 1, av + 1, prefix);
 	usage_with_options(worktree_usage, options);
 }