From f0cd7adaf82f053289a92172ae6165094d646854 Mon Sep 17 00:00:00 2001
From: MacDue <macdue@dueutil.tech>
Date: Sun, 15 Oct 2023 17:10:27 +0100
Subject: [PATCH] LibGUI: Fix FileSystemModel/FileManager after aeee98b

Previously, the null state of m_root_path was use to (subtly) mark the
parent of the root. The empty path is always replaced with "." so after
aeee98b there was no "parent of root" node. This lead to the file
manager crashing when opened.
---
 Userland/Libraries/LibGUI/FileSystemModel.cpp | 16 ++++++++--------
 Userland/Libraries/LibGUI/FileSystemModel.h   | 10 +++++-----
 2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/Userland/Libraries/LibGUI/FileSystemModel.cpp b/Userland/Libraries/LibGUI/FileSystemModel.cpp
index 1d9dd4b1582..6b7266ecbdb 100644
--- a/Userland/Libraries/LibGUI/FileSystemModel.cpp
+++ b/Userland/Libraries/LibGUI/FileSystemModel.cpp
@@ -232,8 +232,8 @@ Optional<FileSystemModel::Node const&> FileSystemModel::node_for_path(Deprecated
     DeprecatedString resolved_path;
     if (path == m_root_path)
         resolved_path = "/";
-    else if (!m_root_path.is_empty() && path.starts_with(m_root_path))
-        resolved_path = LexicalPath::relative_path(path, m_root_path);
+    else if (m_root_path.has_value() && !m_root_path->is_empty() && path.starts_with(*m_root_path))
+        resolved_path = LexicalPath::relative_path(path, *m_root_path);
     else
         resolved_path = path;
     LexicalPath lexical_path(resolved_path);
@@ -269,8 +269,8 @@ DeprecatedString FileSystemModel::full_path(ModelIndex const& index) const
     return node.full_path();
 }
 
-FileSystemModel::FileSystemModel(DeprecatedString root_path, Mode mode)
-    : m_root_path(LexicalPath::canonicalized_path(move(root_path)))
+FileSystemModel::FileSystemModel(Optional<DeprecatedString> root_path, Mode mode)
+    : m_root_path(root_path.map(LexicalPath::canonicalized_path))
     , m_mode(mode)
 {
     setpwent();
@@ -362,12 +362,12 @@ void FileSystemModel::update_node_on_selection(ModelIndex const& index, bool con
     node.set_selected(selected);
 }
 
-void FileSystemModel::set_root_path(DeprecatedString root_path)
+void FileSystemModel::set_root_path(Optional<DeprecatedString> root_path)
 {
-    if (root_path.is_empty())
+    if (!root_path.has_value())
         m_root_path = {};
     else
-        m_root_path = LexicalPath::canonicalized_path(move(root_path));
+        m_root_path = LexicalPath::canonicalized_path(move(*root_path));
     invalidate();
 
     if (m_root->has_error()) {
@@ -382,7 +382,7 @@ void FileSystemModel::invalidate()
 {
     m_root = adopt_own(*new Node(*this));
 
-    if (m_root_path.is_empty())
+    if (!m_root_path.has_value())
         m_root->m_parent_of_root = true;
 
     m_root->reify_if_needed();
diff --git a/Userland/Libraries/LibGUI/FileSystemModel.h b/Userland/Libraries/LibGUI/FileSystemModel.h
index 7eb13024583..ee14d668996 100644
--- a/Userland/Libraries/LibGUI/FileSystemModel.h
+++ b/Userland/Libraries/LibGUI/FileSystemModel.h
@@ -102,14 +102,14 @@ public:
         OwnPtr<Node> create_child(DeprecatedString const& child_name);
     };
 
-    static NonnullRefPtr<FileSystemModel> create(DeprecatedString root_path = "/", Mode mode = Mode::FilesAndDirectories)
+    static NonnullRefPtr<FileSystemModel> create(Optional<DeprecatedString> root_path = "/", Mode mode = Mode::FilesAndDirectories)
     {
         return adopt_ref(*new FileSystemModel(root_path, mode));
     }
     virtual ~FileSystemModel() override = default;
 
-    DeprecatedString root_path() const { return m_root_path; }
-    void set_root_path(DeprecatedString);
+    DeprecatedString root_path() const { return m_root_path.value_or(""); }
+    void set_root_path(Optional<DeprecatedString>);
     DeprecatedString full_path(ModelIndex const&) const;
     ModelIndex index(DeprecatedString path, int column) const;
 
@@ -153,7 +153,7 @@ public:
     void set_allowed_file_extensions(Optional<Vector<DeprecatedString>> const& allowed_file_extensions);
 
 private:
-    FileSystemModel(DeprecatedString root_path, Mode);
+    FileSystemModel(Optional<DeprecatedString> root_path, Mode);
 
     DeprecatedString name_for_uid(uid_t) const;
     DeprecatedString name_for_gid(gid_t) const;
@@ -168,7 +168,7 @@ private:
 
     void handle_file_event(Core::FileWatcherEvent const& event);
 
-    DeprecatedString m_root_path;
+    Optional<DeprecatedString> m_root_path;
     Mode m_mode { Invalid };
     OwnPtr<Node> m_root { nullptr };