Go to http://docs.google.com/
Create a new document
Change the font size from 10pt to 12pt
The font size doesn't change and the select becomes a caret at the beginning of the document. Select All again and change from 10pt to 12pt. The font size changes but you can no longer select text in the document.
The second part (the text becoming unselectable was because of a user style sheet I had enabled to test for another bug. But the first part (the font size not changing and the selection becoming a caret) is a real bug.
Seems like a bug in GoogleDocs. On the first font size change they are:
Inserting an empty text node before the text node that contains "hello"
Clearing the selection with Selection::removeAllRanges()
Setting a selection with Selection::addRange(r) where r is [emptyTextNode, 0] to [emptyTextNode, 0]
Yup, they are aware. Fix should go out with their next push.
Closing as INVALID since this turned out to be a Google bug and was fixed on that end.