How to reproduce:

• Text editor with long text is open (text longer than visible page height)
• Upper part of document is visible.
• Text editor does not have focus.
• User clicks on a line in the document
  What happens:
  Visible portion of the document scrolls to the bottom and the cursor blinks on a line, there.

See attached (animated) screen shot.
The document loses focus, because user clicks into the replace-lineinput. Then, the user clicks on the first line and the document jumps to the end.