the problem can be easily reproduced with Ensemble:

select "Samples"->"Web"->"HTML Editor"
try to select text in the editor.
If you select from beginning to the end selection works fine, but if you will try to select from right to left it doesn't work.
E.g. place cursor at the very end of the text, press Shift-Left and one character will be selected, press Shift-Left one more time
and nothing is selected.