Patch 106381 Comment #3:
When "Open folders during drag operations" is enabled, two things happen, both in the DolphinView and in the Folders Panel:

1) When hovering a folder that can be expanded (this is the case for folders with sub-folders in the Folders Panel and in the DolphinView if in Details View mode), toggle its "expanded" state.
2) When hovering a folder that can not be expanded (i.e., a folder without sub-folders or any folder in Icons or Compact View), open this folder in the DolphinView via the KItemListController's itemActivated(int) signal.

The bug described in bug 293200 comment 3 is that 1) is always wanted, but 2) is not wanted for the Folders Panel.

BUG: 293200
FIXED-IN: 4.9.2