Merge pull request #2036 from Tyriar/protect_markers

Make Terminal.markers readonly

src/public/Terminal.ts

@@ -30,7 +30,7 @@ export class Terminal implements ITerminalApi {
   public get textarea(): HTMLTextAreaElement { return this._core.textarea; }
   public get rows(): number { return this._core.rows; }
   public get cols(): number { return this._core.cols; }
-  public get markers(): IMarker[] { return this._core.markers; }
+  public get markers(): ReadonlyArray<IMarker> { return this._core.markers; }
   public blur(): void {
     this._core.blur();
   }

typings/xterm.d.ts

@@ -359,7 +359,7 @@ declare module 'xterm' {
      * (EXPERIMENTAL) Get all markers registered against the buffer. If the alt
      * buffer is active this will always return [].
      */
-    readonly markers: IMarker[];
+    readonly markers: ReadonlyArray<IMarker>;
 
     /**
      * Natural language strings that can be localized.