Show tree expanders option not working

[joshas]

Preferences -> Item List -> "Show tree expanders" option does nothing when enabled, only adds some padding to left side of file list. This might be due to the fact, that TreeView doesn't have any information about directory contents until they are opened, so expand icons are not displayed.

[MeanEYE]

Functionality is there, but they are not shown immediately. Initially this was solved by adding single empty iter to each directory element in order to force showing of the expander. Due to some issue with this code was removed hence why they don't appear automatically.