Wikimedia Bugzilla is closed!

When editing in the proofread extensions at http://en.wikisource.org/w/index.php?title=Page:The_book_of_try_and_learn.djvu/1&action=edit undo of any insert action either does not undo the insert (in Firefox & Safari Browsers), or selects all of the remaining text after undo (Chrome).

Steps:
1. Edit text at http://en.wikisource.org/w/index.php?title=Page:The_book_of_try_and_learn.djvu/1&action=edit while logged in.
2. Select text in the edit area, and try one of the following: (1. Insert special character. 2. Insert a Hyperlink. 3. Insert a link break).
3. Undo using any method (keyboard shortcut, undo from edit menu or context menu).

Actual: Insertion does not undo in Firefox & Safari. In Chrome all text is selected.

Expected: Undo consistently reverts the last user action in all browsers.