Can't get correct coordinates using TextKit with UITextView?

NSLayoutManager-coordinates.md

So dumb. If you're trying to use boundingRectForGlyphRange… or lineFragmentRectForGlyphAtIndex… on a UITextView's NSLayoutManager, you will get slightly wrong coordinates if the text is longer than a few thousand characters.

…until you:

textView.layoutManager.allowsNonContiguousLayout = false

Then it works perfectly.

Source: http://blog.mugunthkumar.com/coding/radar-15159094-uitextview-nsattributedstring-is-hopelessly-broken-on-ios-7-3/