FileBrowser ListView does not correctly process the mouse-scrolling (horizontally)

ros gcc dbg 0.4.9-dev-584-g3d66048

Reproduction steps:
-open an explorer filebrowser in details view, e.g. in "My computer"
-resize the window to make it have a horizontal scrollbar but no vertical scrollbar
-click into the list view once to give it focus
-now scroll with the mouse wheel

Expected behavior:
-The horizontal scrollbar gets scrolled

Observed behavior:
-scrolling does nothing

Notes:
If listview has only a vertical scrollbar, then we do properly scroll vertically already.
If listView has a vertical and a horizontal scrollbar, we do properly scroll vertically already.
Nothing gets logged when we try any of the above.