Selection text missplaced when lines are removed during the selection

Steps to reproduce:
1. Run TextSelectionTest.mxml
2. Double click on a word to make a selection

Actual Results:
When textFlow.removeChildAt(0) is called to remove the first line, the selection is not moved on the right position.

Expected Results:
The selection must stay on the previously selected text. I'm using a WebChat so older lines are removed. If I want to allow my users to select text, the current behaviour makes this impossible.

Workaround (if any):
Calculate the number of removed characters/elements to remake the selection?

Note : I admit it's not a common use... only chat with buffer limit are impacted.