change buffer interface from IBuffer to IBufferNamespace

addons/xterm-addon-serialize/src/SerializeAddon.ts

@@ -175,8 +175,8 @@ export class SerializeAddon implements ITerminalAddon {
       throw new Error('Cannot use addon until it has been loaded');
     }
 
-    const maxRows = this._terminal.buffer.length;
-    const handler = new StringSerializeHandler(this._terminal.buffer);
+    const maxRows = this._terminal.buffer.active.length;
+    const handler = new StringSerializeHandler(this._terminal.buffer.active);
 
     rows = (rows === undefined) ? maxRows : constrain(rows, 0, maxRows);