Command execution from rendering ANSI Art

[jcubic]

Issue summary

Random errors from rendering ANSI Art

Steps to reproduce

1. Open ANSI Art viewer https://codepen.io/jcubic/pen/pxdxmN?editors=0110
2. type cat 43-CFMN.ANS

Browser and OS

N/A

Additional notes

Escaping the input makes no effect:

str = str.replace(/\[/g, '[').replace(/\]/g, ']');