diff -r 490d5cc509ed -r cf61fcea0001 wp/wp-admin/js/wp-fullscreen-stub.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-admin/js/wp-fullscreen-stub.js	Mon Oct 14 17:39:30 2019 +0200
@@ -0,0 +1,39 @@
+/**
+ * Distraction-Free Writing (wp-fullscreen) backward compatibility stub.
+ * Todo: remove at the end of 2016.
+ *
+ * Original was deprecated in 4.1, removed in 4.3.
+ */
+( function() {
+	var noop = function(){};
+
+	window.wp = window.wp || {};
+	window.wp.editor = window.wp.editor || {};
+	window.wp.editor.fullscreen = {
+		bind_resize: noop,
+		dfwWidth: noop,
+		off: noop,
+		on: noop,
+		refreshButtons: noop,
+		resizeTextarea: noop,
+		save: noop,
+		switchmode: noop,
+		toggleUI: noop,
+
+		settings: {},
+		pubsub: {
+			publish: noop,
+			subscribe: noop,
+			unsubscribe: noop,
+			topics: {}
+		},
+		fade: {
+			In: noop,
+			Out: noop
+		},
+		ui: {
+			fade: noop,
+			init: noop
+		}
+	};
+}());