DnD in treeview mode from an external program always do COPY
When doing a DnD operation from outside Nautilus (for example, from Desktop Icons NG) into one of its windows, if the window is in "iconview mode", Nautilus is able to detect when the origin and the destination folders are in the same disk volume and do a move in that case, or do a copy when they are in different volumes. Unfortunately, when the window is in "treeview mode", this operation doesn't work as expected, and always copy the file(s), no matter if the origin and destination folders are or not in the same volume.
Edited by Rastersoft