16 files changed, 224 insertions, 64 deletions
diff --git a/editor/add_metadata_dialog.cpp b/editor/add_metadata_dialog.cpp
index f40db0e59a..0f4e8f6022 100644
--- a/editor/add_metadata_dialog.cpp
+++ b/editor/add_metadata_dialog.cpp
@@ -66,7 +66,6 @@ AddMetadataDialog::AddMetadataDialog() {
 }
 
 void AddMetadataDialog::_complete_init(const StringName &p_title) {
-	add_meta_name->grab_focus();
 	add_meta_name->set_text("");
 	validation_panel->update();
 
@@ -92,6 +91,7 @@ void AddMetadataDialog::open(const StringName p_title, List<StringName> &p_exist
 	this->_existing_metas = p_existing_metas;
 	_complete_init(p_title);
 	popup_centered();
+	add_meta_name->grab_focus();
 }
 
 StringName AddMetadataDialog::get_meta_name() {
diff --git a/editor/editor_data.cpp b/editor/editor_data.cpp
index f4d044f2fd..542db48f79 100644
--- a/editor/editor_data.cpp
+++ b/editor/editor_data.cpp
@@ -549,6 +549,7 @@ Variant EditorData::instantiate_custom_type(const String &p_type, const String &
 				if (n) {
 					n->set_name(p_type);
 				}
+				n->set_meta(SceneStringName(_custom_type_script), script);
 				((Object *)ob)->set_script(script);
 				return ob;
 			}
@@ -1010,6 +1011,7 @@ Variant EditorData::script_class_instance(const String &p_class) {
 			// Store in a variant to initialize the refcount if needed.
 			Variant obj = ClassDB::instantiate(script->get_instance_base_type());
 			if (obj) {
+				Object::cast_to<Object>(obj)->set_meta(SceneStringName(_custom_type_script), script);
 				obj.operator Object *()->set_script(script);
 			}
 			return obj;
diff --git a/editor/editor_node.cpp b/editor/editor_node.cpp
index c8251e3b45..4d6eb95d9e 100644
--- a/editor/editor_node.cpp
+++ b/editor/editor_node.cpp
@@ -3381,6 +3381,8 @@ void EditorNode::unload_editor_addons() {
 		remove_editor_plugin(E.value, false);
 		memdelete(E.value);
 	}
+
+	addon_name_to_plugin.clear();
 }
 
 void EditorNode::_discard_changes(const String &p_str) {
@@ -4675,6 +4677,11 @@ void EditorNode::stop_child_process(OS::ProcessID p_pid) {
 Ref<Script> EditorNode::get_object_custom_type_base(const Object *p_object) const {
 	ERR_FAIL_NULL_V(p_object, nullptr);
 
+	const Node *node = Object::cast_to<const Node>(p_object);
+	if (node && node->has_meta(SceneStringName(_custom_type_script))) {
+		return node->get_meta(SceneStringName(_custom_type_script));
+	}
+
 	Ref<Script> scr = p_object->get_script();
 
 	if (scr.is_valid()) {
diff --git a/editor/editor_properties.cpp b/editor/editor_properties.cpp
index 714118b863..dc14f927f3 100644
--- a/editor/editor_properties.cpp
+++ b/editor/editor_properties.cpp
@@ -3223,6 +3223,7 @@ void EditorPropertyResource::setup(Object *p_object, const String &p_path, const
 	}
 
 	resource_picker->set_base_type(p_base_type);
+	resource_picker->set_resource_owner(p_object);
 	resource_picker->set_editable(true);
 	resource_picker->set_h_size_flags(SIZE_EXPAND_FILL);
 	add_child(resource_picker);
diff --git a/editor/editor_resource_picker.cpp b/editor/editor_resource_picker.cpp
index 1339543281..c543dc56a4 100644
--- a/editor/editor_resource_picker.cpp
+++ b/editor/editor_resource_picker.cpp
@@ -226,7 +226,9 @@ void EditorResourcePicker::_update_menu_items() {
 		}
 
 		if (is_editable()) {
-			edit_menu->add_icon_item(get_editor_theme_icon(SNAME("Clear")), TTR("Clear"), OBJ_MENU_CLEAR);
+			if (!_is_custom_type_script()) {
+				edit_menu->add_icon_item(get_editor_theme_icon(SNAME("Clear")), TTR("Clear"), OBJ_MENU_CLEAR);
+			}
 			edit_menu->add_icon_item(get_editor_theme_icon(SNAME("Duplicate")), TTR("Make Unique"), OBJ_MENU_MAKE_UNIQUE);
 
 			// Check whether the resource has subresources.
@@ -696,6 +698,16 @@ bool EditorResourcePicker::_is_type_valid(const String &p_type_name, const HashS
 	return false;
 }
 
+bool EditorResourcePicker::_is_custom_type_script() const {
+	Ref<Script> resource_as_script = edited_resource;
+
+	if (resource_as_script.is_valid() && resource_owner && resource_owner->has_meta(SceneStringName(_custom_type_script))) {
+		return true;
+	}
+
+	return false;
+}
+
 Variant EditorResourcePicker::get_drag_data_fw(const Point2 &p_point, Control *p_from) {
 	if (edited_resource.is_valid()) {
 		Dictionary drag_data = EditorNode::get_singleton()->drag_resource(edited_resource, p_from);
@@ -955,6 +967,10 @@ bool EditorResourcePicker::is_toggle_pressed() const {
 	return assign_button->is_pressed();
 }
 
+void EditorResourcePicker::set_resource_owner(Object *p_object) {
+	resource_owner = p_object;
+}
+
 void EditorResourcePicker::set_editable(bool p_editable) {
 	editable = p_editable;
 	assign_button->set_disabled(!editable && !edited_resource.is_valid());
@@ -1100,7 +1116,10 @@ void EditorScriptPicker::set_create_options(Object *p_menu_node) {
 		return;
 	}
 
-	menu_node->add_icon_item(get_editor_theme_icon(SNAME("ScriptCreate")), TTR("New Script..."), OBJ_MENU_NEW_SCRIPT);
+	if (!(script_owner && script_owner->has_meta(SceneStringName(_custom_type_script)))) {
+		menu_node->add_icon_item(get_editor_theme_icon(SNAME("ScriptCreate")), TTR("New Script..."), OBJ_MENU_NEW_SCRIPT);
+	}
+
 	if (script_owner) {
 		Ref<Script> scr = script_owner->get_script();
 		if (scr.is_valid()) {
diff --git a/editor/editor_resource_picker.h b/editor/editor_resource_picker.h
index 9ae97dbd53..442f2f4bbc 100644
--- a/editor/editor_resource_picker.h
+++ b/editor/editor_resource_picker.h
@@ -83,6 +83,8 @@ class EditorResourcePicker : public HBoxContainer {
 		CONVERT_BASE_ID = 1000,
 	};
 
+	Object *resource_owner = nullptr;
+
 	PopupMenu *edit_menu = nullptr;
 
 	void _update_resource_preview(const String &p_path, const Ref<Texture2D> &p_preview, const Ref<Texture2D> &p_small_preview, ObjectID p_obj);
@@ -104,6 +106,7 @@ class EditorResourcePicker : public HBoxContainer {
 	void _ensure_allowed_types() const;
 	bool _is_drop_valid(const Dictionary &p_drag_data) const;
 	bool _is_type_valid(const String &p_type_name, const HashSet<StringName> &p_allowed_types) const;
+	bool _is_custom_type_script() const;
 
 	Variant get_drag_data_fw(const Point2 &p_point, Control *p_from);
 	bool can_drop_data_fw(const Point2 &p_point, const Variant &p_data, Control *p_from) const;
@@ -139,6 +142,8 @@ public:
 	void set_toggle_pressed(bool p_pressed);
 	bool is_toggle_pressed() const;
 
+	void set_resource_owner(Object *p_object);
+
 	void set_editable(bool p_editable);
 	bool is_editable() const;
 
diff --git a/editor/plugins/control_editor_plugin.cpp b/editor/plugins/control_editor_plugin.cpp
index c0461b34b8..0eb2acfa23 100644
--- a/editor/plugins/control_editor_plugin.cpp
+++ b/editor/plugins/control_editor_plugin.cpp
@@ -538,7 +538,6 @@ ControlEditorPopupButton::ControlEditorPopupButton() {
 	set_focus_mode(FOCUS_NONE);
 
 	popup_panel = memnew(PopupPanel);
-	popup_panel->set_theme_type_variation("ControlEditorPopupPanel");
 	add_child(popup_panel);
 	popup_panel->connect("about_to_popup", callable_mp(this, &ControlEditorPopupButton::_popup_visibility_changed).bind(true));
 	popup_panel->connect("popup_hide", callable_mp(this, &ControlEditorPopupButton::_popup_visibility_changed).bind(false));
diff --git a/editor/plugins/script_editor_plugin.cpp b/editor/plugins/script_editor_plugin.cpp
index 6abd99b400..1bbe070851 100644
--- a/editor/plugins/script_editor_plugin.cpp
+++ b/editor/plugins/script_editor_plugin.cpp
@@ -263,6 +263,52 @@ Ref<EditorSyntaxHighlighter> EditorJSONSyntaxHighlighter::_create() const {
 	return syntax_highlighter;
 }
 
+////
+
+void EditorMarkdownSyntaxHighlighter::_update_cache() {
+	highlighter->set_text_edit(text_edit);
+	highlighter->clear_keyword_colors();
+	highlighter->clear_member_keyword_colors();
+	highlighter->clear_color_regions();
+
+	// Disable automatic symbolic highlights, as these don't make sense for prose.
+	highlighter->set_symbol_color(EDITOR_GET("text_editor/theme/highlighting/text_color"));
+	highlighter->set_number_color(EDITOR_GET("text_editor/theme/highlighting/text_color"));
+	highlighter->set_member_variable_color(EDITOR_GET("text_editor/theme/highlighting/text_color"));
+	highlighter->set_function_color(EDITOR_GET("text_editor/theme/highlighting/text_color"));
+
+	// Headings (any level).
+	const Color function_color = EDITOR_GET("text_editor/theme/highlighting/function_color");
+	highlighter->add_color_region("#", "", function_color);
+
+	// Bold.
+	highlighter->add_color_region("**", "**", function_color);
+	// `__bold__` syntax is not supported as color regions must begin with a symbol,
+	// not a character that is valid in an identifier.
+
+	// Code (both inline code and triple-backticks code blocks).
+	const Color code_color = EDITOR_GET("text_editor/theme/highlighting/engine_type_color");
+	highlighter->add_color_region("`", "`", code_color);
+
+	// Link (both references and inline links with URLs). The URL is not highlighted.
+	const Color link_color = EDITOR_GET("text_editor/theme/highlighting/keyword_color");
+	highlighter->add_color_region("[", "]", link_color);
+
+	// Quote.
+	const Color quote_color = EDITOR_GET("text_editor/theme/highlighting/string_color");
+	highlighter->add_color_region(">", "", quote_color, true);
+
+	// HTML comment, which is also supported in Markdown.
+	const Color comment_color = EDITOR_GET("text_editor/theme/highlighting/comment_color");
+	highlighter->add_color_region("<!--", "-->", comment_color);
+}
+
+Ref<EditorSyntaxHighlighter> EditorMarkdownSyntaxHighlighter::_create() const {
+	Ref<EditorMarkdownSyntaxHighlighter> syntax_highlighter;
+	syntax_highlighter.instantiate();
+	return syntax_highlighter;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 /*** SCRIPT EDITOR ****/
@@ -4416,6 +4462,10 @@ ScriptEditor::ScriptEditor(WindowWrapper *p_wrapper) {
 	json_syntax_highlighter.instantiate();
 	register_syntax_highlighter(json_syntax_highlighter);
 
+	Ref<EditorMarkdownSyntaxHighlighter> markdown_syntax_highlighter;
+	markdown_syntax_highlighter.instantiate();
+	register_syntax_highlighter(markdown_syntax_highlighter);
+
 	_update_online_doc();
 }
 
diff --git a/editor/plugins/script_editor_plugin.h b/editor/plugins/script_editor_plugin.h
index 4ef6b30814..84e8bfb498 100644
--- a/editor/plugins/script_editor_plugin.h
+++ b/editor/plugins/script_editor_plugin.h
@@ -122,6 +122,24 @@ public:
 	EditorJSONSyntaxHighlighter() { highlighter.instantiate(); }
 };
 
+class EditorMarkdownSyntaxHighlighter : public EditorSyntaxHighlighter {
+	GDCLASS(EditorMarkdownSyntaxHighlighter, EditorSyntaxHighlighter)
+
+private:
+	Ref<CodeHighlighter> highlighter;
+
+public:
+	virtual void _update_cache() override;
+	virtual Dictionary _get_line_syntax_highlighting_impl(int p_line) override { return highlighter->get_line_syntax_highlighting(p_line); }
+
+	virtual PackedStringArray _get_supported_languages() const override { return PackedStringArray{ "md", "markdown" }; }
+	virtual String _get_name() const override { return TTR("Markdown"); }
+
+	virtual Ref<EditorSyntaxHighlighter> _create() const override;
+
+	EditorMarkdownSyntaxHighlighter() { highlighter.instantiate(); }
+};
+
 ///////////////////////////////////////////////////////////////////////////////
 
 class ScriptEditorQuickOpen : public ConfirmationDialog {
diff --git a/editor/plugins/sprite_2d_editor_plugin.cpp b/editor/plugins/sprite_2d_editor_plugin.cpp
index 7f5ab2e193..bb8c3427f4 100644
--- a/editor/plugins/sprite_2d_editor_plugin.cpp
+++ b/editor/plugins/sprite_2d_editor_plugin.cpp
@@ -595,12 +595,12 @@ Sprite2DEditor::Sprite2DEditor() {
 	add_child(err_dialog);
 
 	debug_uv_dialog = memnew(ConfirmationDialog);
+	debug_uv_dialog->set_size(Size2(960, 540) * EDSCALE);
 	VBoxContainer *vb = memnew(VBoxContainer);
 	debug_uv_dialog->add_child(vb);
 	debug_uv = memnew(Panel);
 	debug_uv->connect(SceneStringName(gui_input), callable_mp(this, &Sprite2DEditor::_debug_uv_input));
 	debug_uv->connect(SceneStringName(draw), callable_mp(this, &Sprite2DEditor::_debug_uv_draw));
-	debug_uv->set_custom_minimum_size(Size2(800, 500) * EDSCALE);
 	debug_uv->set_clip_contents(true);
 	vb->add_margin_child(TTR("Preview:"), debug_uv, true);
 
diff --git a/editor/scene_tree_dock.cpp b/editor/scene_tree_dock.cpp
index 4613e68534..91d3144f48 100644
--- a/editor/scene_tree_dock.cpp
+++ b/editor/scene_tree_dock.cpp
@@ -1669,6 +1669,7 @@ void SceneTreeDock::_notification(int p_what) {
 			button_instance->set_icon(get_editor_theme_icon(SNAME("Instance")));
 			button_create_script->set_icon(get_editor_theme_icon(SNAME("ScriptCreate")));
 			button_detach_script->set_icon(get_editor_theme_icon(SNAME("ScriptRemove")));
+			button_extend_script->set_icon(get_editor_theme_icon(SNAME("ScriptExtend")));
 			button_tree_menu->set_icon(get_editor_theme_icon(SNAME("GuiTabMenuHl")));
 
 			filter->set_right_icon(get_editor_theme_icon(SNAME("Search")));
@@ -2786,33 +2787,49 @@ void SceneTreeDock::_delete_confirm(bool p_cut) {
 }
 
 void SceneTreeDock::_update_script_button() {
-	if (!profile_allow_script_editing) {
-		button_create_script->hide();
-		button_detach_script->hide();
-	} else if (editor_selection->get_selection().size() == 0) {
-		button_create_script->hide();
-		button_detach_script->hide();
-	} else if (editor_selection->get_selection().size() == 1) {
-		Node *n = editor_selection->get_selected_node_list().front()->get();
-		if (n->get_script().is_null()) {
-			button_create_script->show();
-			button_detach_script->hide();
-		} else {
-			button_create_script->hide();
-			button_detach_script->show();
-		}
-	} else {
-		button_create_script->hide();
+	bool can_create_script = false;
+	bool can_detach_script = false;
+	bool can_extend_script = false;
+
+	if (profile_allow_script_editing) {
 		Array selection = editor_selection->get_selected_nodes();
+
 		for (int i = 0; i < selection.size(); i++) {
 			Node *n = Object::cast_to<Node>(selection[i]);
-			if (!n->get_script().is_null()) {
-				button_detach_script->show();
-				return;
+			Ref<Script> s = n->get_script();
+			Ref<Script> cts;
+
+			if (n->has_meta(SceneStringName(_custom_type_script))) {
+				cts = n->get_meta(SceneStringName(_custom_type_script));
+			}
+
+			if (selection.size() == 1) {
+				if (s.is_valid()) {
+					if (cts.is_valid() && s == cts) {
+						can_extend_script = true;
+					}
+				} else {
+					can_create_script = true;
+				}
+			}
+
+			if (s.is_valid()) {
+				if (cts.is_valid()) {
+					if (s != cts) {
+						can_detach_script = true;
+						break;
+					}
+				} else {
+					can_detach_script = true;
+					break;
+				}
 			}
 		}
-		button_detach_script->hide();
 	}
+
+	button_create_script->set_visible(can_create_script);
+	button_detach_script->set_visible(can_detach_script);
+	button_extend_script->set_visible(can_extend_script);
 }
 
 void SceneTreeDock::_selection_changed() {
@@ -3059,7 +3076,28 @@ void SceneTreeDock::_replace_node(Node *p_node, Node *p_by_node, bool p_keep_pro
 	Node *newnode = p_by_node;
 
 	if (p_keep_properties) {
-		Node *default_oldnode = Object::cast_to<Node>(ClassDB::instantiate(oldnode->get_class()));
+		Node *default_oldnode = nullptr;
+
+		// If we're dealing with a custom node type, we need to create a default instance of the custom type instead of the native type for property comparison.
+		if (oldnode->has_meta(SceneStringName(_custom_type_script))) {
+			Ref<Script> cts = oldnode->get_meta(SceneStringName(_custom_type_script));
+			default_oldnode = Object::cast_to<Node>(get_editor_data()->script_class_instance(cts->get_global_name()));
+			if (default_oldnode) {
+				default_oldnode->set_name(cts->get_global_name());
+				get_editor_data()->instantiate_object_properties(default_oldnode);
+			} else {
+				// Legacy custom type, registered with "add_custom_type()".
+				// TODO: Should probably be deprecated in 4.x.
+				const EditorData::CustomType *custom_type = get_editor_data()->get_custom_type_by_path(cts->get_path());
+				if (custom_type) {
+					default_oldnode = Object::cast_to<Node>(get_editor_data()->instantiate_custom_type(custom_type->name, cts->get_instance_base_type()));
+				}
+			}
+		}
+
+		if (!default_oldnode) {
+			default_oldnode = Object::cast_to<Node>(ClassDB::instantiate(oldnode->get_class()));
+		}
 
 		List<PropertyInfo> pinfo;
 		oldnode->get_property_list(&pinfo);
@@ -3544,6 +3582,27 @@ void SceneTreeDock::_script_dropped(const String &p_file, NodePath p_to) {
 		undo_redo->add_undo_method(ed, "live_debug_remove_node", NodePath(String(edited_scene->get_path_to(n)).path_join(new_node->get_name())));
 		undo_redo->commit_action();
 	} else {
+		// Check if dropped script is compatible.
+		if (n->has_meta(SceneStringName(_custom_type_script))) {
+			Ref<Script> ct_scr = n->get_meta(SceneStringName(_custom_type_script));
+			if (!scr->inherits_script(ct_scr)) {
+				String custom_type_name = ct_scr->get_global_name();
+
+				// Legacy custom type, registered with "add_custom_type()".
+				if (custom_type_name.is_empty()) {
+					const EditorData::CustomType *custom_type = get_editor_data()->get_custom_type_by_path(ct_scr->get_path());
+					if (custom_type) {
+						custom_type_name = custom_type->name;
+					} else {
+						custom_type_name = TTR("<unknown>");
+					}
+				}
+
+				WARN_PRINT_ED(vformat("Script does not extend type: '%s'.", custom_type_name));
+				return;
+			}
+		}
+
 		undo_redo->create_action(TTR("Attach Script"), UndoRedo::MERGE_DISABLE, n);
 		undo_redo->add_do_method(InspectorDock::get_singleton(), "store_script_properties", n);
 		undo_redo->add_undo_method(InspectorDock::get_singleton(), "store_script_properties", n);
@@ -3651,6 +3710,7 @@ void SceneTreeDock::_tree_rmb(const Vector2 &p_menu_pos) {
 
 	Ref<Script> existing_script;
 	bool existing_script_removable = true;
+	bool allow_attach_new_script = true;
 	if (selection.size() == 1) {
 		Node *selected = selection.front()->get();
 
@@ -3674,6 +3734,10 @@ void SceneTreeDock::_tree_rmb(const Vector2 &p_menu_pos) {
 		if (EditorNode::get_singleton()->get_object_custom_type_base(selected) == existing_script) {
 			existing_script_removable = false;
 		}
+
+		if (selected->has_meta(SceneStringName(_custom_type_script))) {
+			allow_attach_new_script = false;
+		}
 	}
 
 	if (profile_allow_editing) {
@@ -3694,7 +3758,10 @@ void SceneTreeDock::_tree_rmb(const Vector2 &p_menu_pos) {
 
 		if (full_selection.size() == 1) {
 			add_separator = true;
-			menu->add_icon_shortcut(get_editor_theme_icon(SNAME("ScriptCreate")), ED_GET_SHORTCUT("scene_tree/attach_script"), TOOL_ATTACH_SCRIPT);
+			if (allow_attach_new_script) {
+				menu->add_icon_shortcut(get_editor_theme_icon(SNAME("ScriptCreate")), ED_GET_SHORTCUT("scene_tree/attach_script"), TOOL_ATTACH_SCRIPT);
+			}
+
 			if (existing_script.is_valid()) {
 				menu->add_icon_shortcut(get_editor_theme_icon(SNAME("ScriptExtend")), ED_GET_SHORTCUT("scene_tree/extend_script"), TOOL_EXTEND_SCRIPT);
 			}
@@ -4603,6 +4670,14 @@ SceneTreeDock::SceneTreeDock(Node *p_scene_root, EditorSelection *p_editor_selec
 	filter_hbc->add_child(button_detach_script);
 	button_detach_script->hide();
 
+	button_extend_script = memnew(Button);
+	button_extend_script->set_flat(true);
+	button_extend_script->connect(SceneStringName(pressed), callable_mp(this, &SceneTreeDock::_tool_selected).bind(TOOL_EXTEND_SCRIPT, false));
+	button_extend_script->set_tooltip_text(TTR("Extend the script of the selected node."));
+	button_extend_script->set_shortcut(ED_GET_SHORTCUT("scene_tree/extend_script"));
+	filter_hbc->add_child(button_extend_script);
+	button_extend_script->hide();
+
 	button_tree_menu = memnew(MenuButton);
 	button_tree_menu->set_flat(false);
 	button_tree_menu->set_theme_type_variation("FlatMenuButton");
diff --git a/editor/scene_tree_dock.h b/editor/scene_tree_dock.h
index 1c59f7ea1d..44b4e68172 100644
--- a/editor/scene_tree_dock.h
+++ b/editor/scene_tree_dock.h
@@ -117,6 +117,7 @@ class SceneTreeDock : public VBoxContainer {
 	Button *button_instance = nullptr;
 	Button *button_create_script = nullptr;
 	Button *button_detach_script = nullptr;
+	Button *button_extend_script = nullptr;
 	MenuButton *button_tree_menu = nullptr;
 
 	Button *node_shortcuts_toggle = nullptr;
diff --git a/editor/themes/editor_theme_manager.cpp b/editor/themes/editor_theme_manager.cpp
index 3aa1f16f4b..85b850b7f5 100644
--- a/editor/themes/editor_theme_manager.cpp
+++ b/editor/themes/editor_theme_manager.cpp
@@ -643,6 +643,16 @@ void EditorThemeManager::_create_shared_styles(const Ref<EditorTheme> &p_theme,
 			// in 4.0, and even if it was, it may not always work in practice (e.g. running with compositing disabled).
 			p_config.popup_style->set_corner_radius_all(0);
 
+			p_config.popup_border_style = p_config.popup_style->duplicate();
+			p_config.popup_border_style->set_content_margin_all(MAX(Math::round(EDSCALE), p_config.border_width) + 2 + (p_config.base_margin * 1.5) * EDSCALE);
+			// Always display a border for popups like PopupMenus so they can be distinguished from their background.
+			p_config.popup_border_style->set_border_width_all(MAX(Math::round(EDSCALE), p_config.border_width));
+			if (p_config.draw_extra_borders) {
+				p_config.popup_border_style->set_border_color(p_config.extra_border_color_2);
+			} else {
+				p_config.popup_border_style->set_border_color(p_config.dark_color_2);
+			}
+
 			p_config.window_style = p_config.popup_style->duplicate();
 			p_config.window_style->set_border_color(p_config.base_color);
 			p_config.window_style->set_border_width(SIDE_TOP, 24 * EDSCALE);
@@ -717,7 +727,7 @@ void EditorThemeManager::_populate_standard_styles(const Ref<EditorTheme> &p_the
 		}
 
 		// PopupPanel
-		p_theme->set_stylebox(SceneStringName(panel), "PopupPanel", p_config.popup_style);
+		p_theme->set_stylebox(SceneStringName(panel), "PopupPanel", p_config.popup_border_style);
 	}
 
 	// Buttons.
@@ -1324,18 +1334,11 @@ void EditorThemeManager::_populate_standard_styles(const Ref<EditorTheme> &p_the
 
 		// PopupMenu.
 		{
-			Ref<StyleBoxFlat> style_popup_menu = p_config.popup_style->duplicate();
+			Ref<StyleBoxFlat> style_popup_menu = p_config.popup_border_style->duplicate();
 			// Use 1 pixel for the sides, since if 0 is used, the highlight of hovered items is drawn
 			// on top of the popup border. This causes a 'gap' in the panel border when an item is highlighted,
 			// and it looks weird. 1px solves this.
-			style_popup_menu->set_content_margin_individual(EDSCALE, 2 * EDSCALE, EDSCALE, 2 * EDSCALE);
-			// Always display a border for PopupMenus so they can be distinguished from their background.
-			style_popup_menu->set_border_width_all(EDSCALE);
-			if (p_config.draw_extra_borders) {
-				style_popup_menu->set_border_color(p_config.extra_border_color_2);
-			} else {
-				style_popup_menu->set_border_color(p_config.dark_color_2);
-			}
+			style_popup_menu->set_content_margin_individual(Math::round(EDSCALE), 2 * EDSCALE, Math::round(EDSCALE), 2 * EDSCALE);
 			p_theme->set_stylebox(SceneStringName(panel), "PopupMenu", style_popup_menu);
 
 			Ref<StyleBoxFlat> style_menu_hover = p_config.button_style_hover->duplicate();
@@ -1345,17 +1348,17 @@ void EditorThemeManager::_populate_standard_styles(const Ref<EditorTheme> &p_the
 
 			Ref<StyleBoxLine> style_popup_separator(memnew(StyleBoxLine));
 			style_popup_separator->set_color(p_config.separator_color);
-			style_popup_separator->set_grow_begin(p_config.popup_margin - MAX(Math::round(EDSCALE), p_config.border_width));
-			style_popup_separator->set_grow_end(p_config.popup_margin - MAX(Math::round(EDSCALE), p_config.border_width));
+			style_popup_separator->set_grow_begin(Math::round(EDSCALE) - MAX(Math::round(EDSCALE), p_config.border_width));
+			style_popup_separator->set_grow_end(Math::round(EDSCALE) - MAX(Math::round(EDSCALE), p_config.border_width));
 			style_popup_separator->set_thickness(MAX(Math::round(EDSCALE), p_config.border_width));
 
 			Ref<StyleBoxLine> style_popup_labeled_separator_left(memnew(StyleBoxLine));
-			style_popup_labeled_separator_left->set_grow_begin(p_config.popup_margin - MAX(Math::round(EDSCALE), p_config.border_width));
+			style_popup_labeled_separator_left->set_grow_begin(Math::round(EDSCALE) - MAX(Math::round(EDSCALE), p_config.border_width));
 			style_popup_labeled_separator_left->set_color(p_config.separator_color);
 			style_popup_labeled_separator_left->set_thickness(MAX(Math::round(EDSCALE), p_config.border_width));
 
 			Ref<StyleBoxLine> style_popup_labeled_separator_right(memnew(StyleBoxLine));
-			style_popup_labeled_separator_right->set_grow_end(p_config.popup_margin - MAX(Math::round(EDSCALE), p_config.border_width));
+			style_popup_labeled_separator_right->set_grow_end(Math::round(EDSCALE) - MAX(Math::round(EDSCALE), p_config.border_width));
 			style_popup_labeled_separator_right->set_color(p_config.separator_color);
 			style_popup_labeled_separator_right->set_thickness(MAX(Math::round(EDSCALE), p_config.border_width));
 
@@ -2133,21 +2136,6 @@ void EditorThemeManager::_populate_editor_styles(const Ref<EditorTheme> &p_theme
 
 		// EditorValidationPanel.
 		p_theme->set_stylebox(SceneStringName(panel), "EditorValidationPanel", p_config.tree_panel_style);
-
-		// ControlEditor.
-		{
-			p_theme->set_type_variation("ControlEditorPopupPanel", "PopupPanel");
-
-			Ref<StyleBoxFlat> control_editor_popup_style = p_config.popup_style->duplicate();
-			control_editor_popup_style->set_shadow_size(0);
-			control_editor_popup_style->set_content_margin(SIDE_LEFT, p_config.base_margin * EDSCALE);
-			control_editor_popup_style->set_content_margin(SIDE_TOP, p_config.base_margin * EDSCALE);
-			control_editor_popup_style->set_content_margin(SIDE_RIGHT, p_config.base_margin * EDSCALE);
-			control_editor_popup_style->set_content_margin(SIDE_BOTTOM, p_config.base_margin * EDSCALE);
-			control_editor_popup_style->set_border_width_all(0);
-
-			p_theme->set_stylebox(SceneStringName(panel), "ControlEditorPopupPanel", control_editor_popup_style);
-		}
 	}
 
 	// Editor inspector.
diff --git a/editor/themes/editor_theme_manager.h b/editor/themes/editor_theme_manager.h
index 64ea5a43b4..630dc4c9c4 100644
--- a/editor/themes/editor_theme_manager.h
+++ b/editor/themes/editor_theme_manager.h
@@ -137,6 +137,7 @@ class EditorThemeManager {
 		Ref<StyleBoxFlat> button_style_hover;
 
 		Ref<StyleBoxFlat> popup_style;
+		Ref<StyleBoxFlat> popup_border_style;
 		Ref<StyleBoxFlat> window_style;
 		Ref<StyleBoxFlat> dialog_style;
 		Ref<StyleBoxFlat> panel_container_style;
diff --git a/editor/window_wrapper.cpp b/editor/window_wrapper.cpp
index 54b4eafa03..f6de69771e 100644
--- a/editor/window_wrapper.cpp
+++ b/editor/window_wrapper.cpp
@@ -393,7 +393,6 @@ void ScreenSelect::_notification(int p_what) {
 		} break;
 		case NOTIFICATION_THEME_CHANGED: {
 			set_icon(get_editor_theme_icon("MakeFloating"));
-			popup_background->add_theme_style_override(SceneStringName(panel), get_theme_stylebox("PanelForeground", EditorStringName(EditorStyles)));
 
 			const real_t popup_height = real_t(get_theme_font_size(SceneStringName(font_size))) * 2.0;
 			popup->set_min_size(Size2(0, popup_height * 3));
@@ -456,14 +455,10 @@ ScreenSelect::ScreenSelect() {
 	// Create the popup.
 	const Size2 borders = Size2(4, 4) * EDSCALE;
 
-	popup = memnew(Popup);
+	popup = memnew(PopupPanel);
 	popup->connect("popup_hide", callable_mp(static_cast<BaseButton *>(this), &ScreenSelect::set_pressed).bind(false));
 	add_child(popup);
 
-	popup_background = memnew(Panel);
-	popup_background->set_anchors_and_offsets_preset(PRESET_FULL_RECT);
-	popup->add_child(popup_background);
-
 	MarginContainer *popup_root = memnew(MarginContainer);
 	popup_root->add_theme_constant_override("margin_right", borders.width);
 	popup_root->add_theme_constant_override("margin_top", borders.height);
diff --git a/editor/window_wrapper.h b/editor/window_wrapper.h
index 0df7397318..dc65cd056b 100644
--- a/editor/window_wrapper.h
+++ b/editor/window_wrapper.h
@@ -90,7 +90,6 @@ class ScreenSelect : public Button {
 	GDCLASS(ScreenSelect, Button);
 
 	Popup *popup = nullptr;
-	Panel *popup_background = nullptr;
 	HBoxContainer *screen_list = nullptr;
 
 	void _build_advanced_menu();