1 files changed, 63 insertions, 0 deletions
diff --git a/builtin/worktree.c b/builtin/worktree.c
index 2838254f7f..c6eb636329 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -335,6 +335,69 @@ 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) {
+		char *from_file = git_pathdup("info/sparse-checkout");
+		char *to_file = xstrfmt("%s/info/sparse-checkout",
+					sb_repo.buf);
+
+		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);
+	}
+
+	/*
+	 * 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) {
+		char *from_file = git_pathdup("config.worktree");
+		char *to_file = xstrfmt("%s/config.worktree",
+					sb_repo.buf);
+
+		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 'core.bare' in '%s'"), 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 'core.worktree' in '%s'"), to_file);
+
+			git_configset_clear(&cs);
+		}
+
+worktree_copy_cleanup:
+		free(from_file);
+		free(to_file);
+	}
+
 	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;