A readOnly editor doesn't honor readonly in the textArea (#81394)

A readOnly editor doesn't honor readonly in the textArea

src/vs/editor/browser/controller/textAreaHandler.ts

@@ -152,6 +152,10 @@ export class TextAreaHandler extends ViewPart {
 		this.textArea.setAttribute('aria-haspopup', 'false');
 		this.textArea.setAttribute('aria-autocomplete', 'both');
 
+		if (platform.isWeb && options.get(EditorOption.readOnly)) {
+			this.textArea.setAttribute('readonly', 'true');
+		}
+
 		this.textAreaCover = createFastDomNode(document.createElement('div'));
 		this.textAreaCover.setPosition('absolute');
 
@@ -395,6 +399,14 @@ export class TextAreaHandler extends ViewPart {
 		this._copyWithSyntaxHighlighting = options.get(EditorOption.copyWithSyntaxHighlighting);
 		this.textArea.setAttribute('aria-label', this._getAriaLabel(options));
 
+		if (platform.isWeb && e.hasChanged(EditorOption.readOnly)) {
+			if (options.get(EditorOption.readOnly)) {
+				this.textArea.setAttribute('readonly', 'true');
+			} else {
+				this.textArea.removeAttribute('readonly');
+			}
+		}
+
 		if (e.hasChanged(EditorOption.accessibilitySupport)) {
 			this._textAreaInput.writeScreenReaderContent('strategy changed');
 		}