switch back to blocking gutenberg undo altogether when classic block …

…focused

packages/block-library/src/classic/edit.js

@@ -34,7 +34,6 @@ export default class ClassicEdit extends Component {
 		this.initialize = this.initialize.bind( this );
 		this.onSetup = this.onSetup.bind( this );
 		this.focus = this.focus.bind( this );
-		this.state = { lastUndo: false };
 	}
 
 	componentDidMount() {
@@ -138,7 +137,8 @@ export default class ClassicEdit extends Component {
 
 		editor.on( 'keydown', ( event ) => {
 			if ( isKeyboardEvent.primary( event, 'z' ) ) {
-				this.handleUndo( event );
+				// Prevent the gutenberg undo kicking in so TinyMCE undo stack works as expected
+				event.stopPropagation();
 			}
 
 			if (
@@ -215,19 +215,6 @@ export default class ClassicEdit extends Component {
 		event.nativeEvent.stopImmediatePropagation();
 	}
 
-	handleUndo( event ) {
-		// While there is content in the block prevent Gutenberg undo from kicking in so TinyMCE undo stack works.
-		// Need to also track if it is the last undo otherwise block is removed along with last bit of content.
-		if ( isTmceEmpty( this.editor ) && ! this.state.lastUndo ) {
-			this.setState( { lastUndo: true } );
-			event.stopPropagation();
-		}
-		if ( ! isTmceEmpty( this.editor ) ) {
-			this.setState( { lastUndo: false } );
-			event.stopPropagation();
-		}
-	}
-
 	render() {
 		const { clientId } = this.props;