Fix terminal race condition (afterViewInit vs WS connection)

src/app/services/terminado.service.ts

@@ -7,6 +7,7 @@ import * as terminado from 'xterm/lib/addons/terminado/terminado';
 export class TerminadoService {
   xterm: Terminal;
   ws: WebSocket;
+  attached = false;
 
   constructor() {
     Terminal.applyAddon(fit);
@@ -47,6 +48,7 @@ export class TerminadoService {
       this.xterm.open(element);
       this.fit();
       this.xterm.blur();
+      this.attached = true;
     };
   }
 
@@ -54,9 +56,12 @@ export class TerminadoService {
     (<any>this.xterm).terminadoDetach(this.ws);
     this.xterm.destroy();
     this.ws.close();
+    this.attached = false;
   }
 
   fit() {
-    (<any>this.xterm).fit();
+    if (this.attached) {
+      (<any>this.xterm).fit();
+    }
   }
 }