0.79: Folder handle not released in XnViewMP

[CreativeWorld]

This is in reference to http://www.xnview.com/mantisbt/view.php?id=588, but provides more information and instructions on how to reproduce the bug.
In XnViewMP 0.79, folder handles of sub-folders are not released, preventing deletion/moving of the parent folder.

Here is how to reproduce the bug:

1) Create the following folder structure in Windows File Explorer (not in XnView itself!): Main -> Parent -> Child
2) In the XnViewMP tree pane, navigate to the "Main" folder.
3) Switch to the XnViewMP thumbnail pane, enter the "Parent" Folder, and then enter the "Child" folder.
4) Still in the thumbnail pane, move up (".." or "up arrow icon") one level into the "Parent" Folder, and then up again into the "Main" Folder
5) In the "Main" folder, delete the "Parent" folder by pressing the "del" key.
=> XnViewMP cannot delete the "Parent" folder, because it did not close the file handle of the "Child" folder. This can be seen in Process Explorer.
In addition, the "Parent" folder will disappear from the thumbnail pane (as if it was deleted), but it will still be shown in the tree pane. The CPU-use of XnViewMP will increase to 100 %.

Note that this bug does not occur, if the "Parent" folder is deleted from within the tree pane, or if you navigated to the "Child" folder directly in the tree pane and then switched to the thumbnail pane. If you created the folder structure with XnViewMP instead of Windows File Explorer, you have to restart XnViewMP and start at step 2), in order to provoke the bug.

I hope this helps fixing this bug. XnView is awesome, and I love that you took the idea further with XnViewMP on other operating systems than Windows!

[xnview]

See Issue 846 for current status and details.

[helmut]

According to the bug tracker, issue 846 is supposed to be fixed while issue 588 is still open.

@CreativeWorld: Could you please check with the latest XnView MP 0.84 and post your result, here?