quilljs/quill — pull request #243 by thomsbg (2014-10-31 20:40:09+00:00)
Title: Do not modify argument to setContents()

I noticed in my app that the argument I pass to `quill.setContents(delta)` gets modified in place (a delete operation is prepended).

This uses `slice()` to ensure that the unshift operation happens on a copy of the array.