Read-only sketches are editable

[TomBinford]

Steps to reproduce:

• log in as guest
• open the default Processing sketch
• make a simple change like drawing a circle at (0, 0)
• click the Share button and copy the link
• open the link in an Incognito window Observe you can modify the source code and run it, but any edits to the source don't change the output. In read-only mode, the source should not have been editable to begin with.

[mizlan]

https://discuss.codemirror.net/t/codemirror-read-only-mode/1936/5