worktree: implement `git_worktree_list`

Add new module for working trees with the `git_worktree_list`
function. The function lists names for all working trees of a
certain repository.

1 files changed, 58 insertions, 0 deletions

diff --git a/src/worktree.c b/src/worktree.c
new file mode 100644
index 000000000..28d895d5c
--- /dev/null
+++ b/src/worktree.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "git2/worktree.h"
+
+#include "common.h"
+#include "repository.h"
+
+static bool is_worktree_dir(git_buf *dir)
+{
+	return git_path_contains_file(dir, "commondir")
+		&& git_path_contains_file(dir, "gitdir")
+		&& git_path_contains_file(dir, "HEAD");
+}
+
+int git_worktree_list(git_strarray *wts, git_repository *repo)
+{
+	git_vector worktrees = GIT_VECTOR_INIT;
+	git_buf path = GIT_BUF_INIT;
+	char *worktree;
+	unsigned i, len;
+	int error;
+
+	assert(wts && repo);
+
+	wts->count = 0;
+	wts->strings = NULL;
+
+	if ((error = git_buf_printf(&path, "%s/worktrees/", repo->commondir)) < 0)
+		goto exit;
+	if (!git_path_exists(path.ptr) || git_path_is_empty_dir(path.ptr))
+		goto exit;
+	if ((error = git_path_dirload(&worktrees, path.ptr, path.size, 0x0)) < 0)
+		goto exit;
+
+	len = path.size;
+
+	git_vector_foreach(&worktrees, i, worktree) {
+		git_buf_truncate(&path, len);
+		git_buf_puts(&path, worktree);
+
+		if (!is_worktree_dir(&path)) {
+			git_vector_remove(&worktrees, i);
+			git__free(worktree);
+		}
+	}
+
+	wts->strings = (char **)git_vector_detach(&wts->count, NULL, &worktrees);
+
+exit:
+	git_buf_free(&path);
+
+	return error;
+}