Description of problem:
If you drag&drop a panel over the Project Explorer (Project authoring perspective), it can no longer be moved back. If you drop it so that it covers the Project Explorer, you cannot switch to Project Explorer.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Open Project authoring perspective. Open an asset editor.
2. Grab that editor's panel header and drag it over to the Project Explorer panel.
3. Drop it over the middle part (blue square) of the "compass" widget.
4. Try either of the following:
Grab the editor's panel header again and drag it back.
Switch to Project Explorer (same way as you switch two asset editors that have been opened in the same panel).
Step 4 is impossible to do.
The asset editor can be moved in step 4 and it is possible to switch to the Project Explorer.
Same thing for the Administration perspective and dropping panels over the File Explorer.
Actually the same problem will be with all split panels - or rather their left parts.
Reassigning to Christian since this is an UberFire issue.
The project explorer, file explorer etc. are no longer drop targets in 6.3 (community) and 6.2 (product) so this should not be an issue anymore. Other split panels I tested also didn't have that problem anymore but needs confirmation.