Fix reloading scripts already in use

core/object/script_language.cpp

@@ -191,7 +191,14 @@ void Script::reload_from_file() {
  set_source_code(rel->get_source_code());
  set_last_modified_time(rel->get_last_modified_time());
 
- reload();
+ if (Engine::get_singleton()->is_editor_hint() && is_tool()) {
+ get_language()->reload_tool_script(this, true);
+ } else {
+ // It's important to set p_keep_state to true in order to manage reloading scripts
+ // that are currently instantiated.
+ reload(true);
+ }
+
 #else
  Resource::reload_from_file();
 #endif

editor/editor_file_system.cpp

@@ -1973,18 +1973,16 @@ void EditorFileSystem::_update_script_documentation() {
  for (int i = 0; i < ScriptServer::get_language_count(); i++) {
  ScriptLanguage *lang = ScriptServer::get_language(i);
  if (lang->supports_documentation() && efd->files[index]->type == lang->get_type()) {
- // Reloading the script from disk if resource already in memory. Otherwise, the
- // ResourceLoader::load will return the last loaded version of the script (without the modifications).
- // The only have the script already loaded here is to edit the script outside the
- // editor without being connected to the LSP server.
- Ref<Resource> res = ResourceCache::get_ref(path);
- if (res.is_valid()) {
- res->reload_from_file();
- }
+ bool should_reload_script = _should_reload_script(path);
  Ref<Script> scr = ResourceLoader::load(path);
  if (scr.is_null()) {
  continue;
  }
+ if (should_reload_script) {
+ // Reloading the script from disk. Otherwise, the ResourceLoader::load will
+ // return the last loaded version of the script (without the modifications).
+ scr->reload_from_file();
+ }
  Vector<DocData::ClassDoc> docs = scr->get_documentation();
  for (int j = 0; j < docs.size(); j++) {
  EditorHelp::get_doc_data()->add_doc(docs[j]);
@@ -2006,6 +2004,36 @@ void EditorFileSystem::_update_script_documentation() {
  update_script_paths_documentation.clear();
 }
 
+bool EditorFileSystem::_should_reload_script(const String &p_path) {
+ if (first_scan) {
+ return false;
+ }
+
+ Ref<Resource> res = ResourceCache::get_ref(p_path);
+ if (res.is_null()) {
+ // Script not already loaded.
+ return false;
+ }
+
+ Ref<Script> scr = res;
+ if (scr.is_null()) {
+ // Not a script.
+ return false;
+ }
+
+ // Scripts are reloaded via the script editor if they are currently opened.
+ if (ScriptEditor::get_singleton()->get_open_scripts().has(scr)) {
+ return false;
+ }
+
+ if (res->get_last_modified_time() == FileAccess::get_modified_time(p_path)) {
+ // Already up to date.
+ return false;
+ }
+
+ return true;
+}
+
 void EditorFileSystem::_process_update_pending() {
  _update_script_classes();
  // Parse documentation second, as it requires the class names to be loaded

editor/editor_file_system.h

@@ -295,6 +295,7 @@ class EditorFileSystem : public Node {
  void _update_script_documentation();
  void _process_update_pending();
  void _process_removed_files(const HashSet<String> &p_processed_files);
+ bool _should_reload_script(const String &p_path);
 
  Mutex update_scene_mutex;
  HashSet<String> update_scene_paths;

editor/editor_node.cpp

@@ -944,6 +944,12 @@ void EditorNode::_resources_changed(const Vector<String> &p_resources) {
  continue;
  }
 
+ if (res->get_last_modified_time() == FileAccess::get_modified_time(res->get_path())) {
+ // Already up to date. That prevents reloading a script already reloaded for documentation
+ // in EditorFileSystem::_update_script_documentation.
+ continue;
+ }
+
  changed.push_back(res);
  }