1 files changed, 86 insertions, 11 deletions

diff --git a/builtin/worktree.c b/builtin/worktree.c
index 0d0809276f..4eaba2a8fd 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -236,6 +236,74 @@ static void check_candidate_path(const char *path,
 		die(_("'%s' is a missing but already registered worktree;\nuse '%s -f' to override, or 'prune' or 'remove' to clear"), path, cmd);
 }
 
+static void copy_sparse_checkout(const char *worktree_git_dir)
+{
+	char *from_file = git_pathdup("info/sparse-checkout");
+	char *to_file = xstrfmt("%s/info/sparse-checkout", worktree_git_dir);
+
+	if (file_exists(from_file)) {
+		if (safe_create_leading_directories(to_file) ||
+			copy_file(to_file, from_file, 0666))
+			error(_("failed to copy '%s' to '%s'; sparse-checkout may not work correctly"),
+				from_file, to_file);
+	}
+
+	free(from_file);
+	free(to_file);
+}
+
+static void copy_filtered_worktree_config(const char *worktree_git_dir)
+{
+	char *from_file = git_pathdup("config.worktree");
+	char *to_file = xstrfmt("%s/config.worktree", worktree_git_dir);
+
+	if (file_exists(from_file)) {
+		struct config_set cs = { { 0 } };
+		const char *core_worktree;
+		int bare;
+
+		if (safe_create_leading_directories(to_file) ||
+			copy_file(to_file, from_file, 0666)) {
+			error(_("failed to copy worktree config from '%s' to '%s'"),
+				from_file, to_file);
+			goto worktree_copy_cleanup;
+		}
+
+		git_configset_init(&cs);
+		git_configset_add_file(&cs, from_file);
+
+		if (!git_configset_get_bool(&cs, "core.bare", &bare) &&
+			bare &&
+			git_config_set_multivar_in_file_gently(
+				to_file, "core.bare", NULL, "true", 0))
+			error(_("failed to unset '%s' in '%s'"),
+				"core.bare", to_file);
+		if (!git_configset_get_value(&cs, "core.worktree", &core_worktree) &&
+			git_config_set_in_file_gently(to_file,
+							"core.worktree", NULL))
+			error(_("failed to unset '%s' in '%s'"),
+				"core.worktree", to_file);
+
+		git_configset_clear(&cs);
+	}
+
+worktree_copy_cleanup:
+	free(from_file);
+	free(to_file);
+}
+
+static int checkout_worktree(const struct add_opts *opts,
+			     struct strvec *child_env)
+{
+	struct child_process cp = CHILD_PROCESS_INIT;
+	cp.git_cmd = 1;
+	strvec_pushl(&cp.args, "reset", "--hard", "--no-recurse-submodules", NULL);
+	if (opts->quiet)
+		strvec_push(&cp.args, "--quiet");
+	strvec_pushv(&cp.env_array, child_env->v);
+	return run_command(&cp);
+}
+
 static int add_worktree(const char *path, const char *refname,
 			const struct add_opts *opts)
 {
@@ -335,6 +403,21 @@ static int add_worktree(const char *path, const char *refname,
 	strbuf_addf(&sb, "%s/commondir", sb_repo.buf);
 	write_file(sb.buf, "../..");
 
+	/*
+	 * If the current worktree has sparse-checkout enabled, then copy
+	 * the sparse-checkout patterns from the current worktree.
+	 */
+	if (core_apply_sparse_checkout)
+		copy_sparse_checkout(sb_repo.buf);
+
+	/*
+	 * If we are using worktree config, then copy all current config
+	 * values from the current worktree into the new one, that way the
+	 * new worktree behaves the same as this one.
+	 */
+	if (repository_format_worktree_config)
+		copy_filtered_worktree_config(sb_repo.buf);
+
 	strvec_pushf(&child_env, "%s=%s", GIT_DIR_ENVIRONMENT, sb_git.buf);
 	strvec_pushf(&child_env, "%s=%s", GIT_WORK_TREE_ENVIRONMENT, path);
 	cp.git_cmd = 1;
@@ -354,17 +437,9 @@ static int add_worktree(const char *path, const char *refname,
 	if (ret)
 		goto done;
 
-	if (opts->checkout) {
-		struct child_process cp = CHILD_PROCESS_INIT;
-		cp.git_cmd = 1;
-		strvec_pushl(&cp.args, "reset", "--hard", "--no-recurse-submodules", NULL);
-		if (opts->quiet)
-			strvec_push(&cp.args, "--quiet");
-		strvec_pushv(&cp.env_array, child_env.v);
-		ret = run_command(&cp);
-		if (ret)
-			goto done;
-	}
+	if (opts->checkout &&
+	    (ret = checkout_worktree(opts, &child_env)))
+		goto done;
 
 	is_junk = 0;
 	FREE_AND_NULL(junk_work_tree);