Cacio is Leaking

[fra.orolo at mailfish.de]

[Second post with smaller attachments to get through]

Dear cacio developers,

I finally managed to get Cacio running as the GUI backend for running
tests in our CI system.
The preliminary fixes for clipboard and screen resolution helped a
lot. The problems on Windows have been
resolved by using Metal UI instead of Native LAF.

We discovered some more problems though:
 * We have one test where a visualizer with a rectangular grid is
tested for "box selection" gestures:

 Point lup = new Point(10,1);
 Point rlp = new Point(50,21);
 robot.pressMouse(target, lup, MouseButton.LEFT_BUTTON);
 robot.moveMouse(target, rlp);
 robot.releaseMouseButtons();

 This used to work with xvnc and generated mouse drag events that are
captured to select cells of the grid.
 These drag events are no longer generated.

* In some of our tests we open a Popup on a table, just to check
whether certain items are disabled.
 After this was done, the test did a click outside the popup to close it.
 This pattern breaks the test with Cacio, as this popup keeps the
keyboard focus and later text input actions fail, because
 they are unable to obtain the focus.

* The biggest issue last: Some of our tests are Memory Leak tests:
  0 They start an application
  1 load some dataset and
  2 perform some operations
  3 measure the allocated memory of the VM
  4 drop the dataset and repeat the cycle from step 1 (let's say 10
times or so)

 The expectation is that the allocated Memory should stay somehow
stable in step 3.
 I must at least not grow proportionally with the number of cycles.

 With Cacio as the backend we discovered a leak:

 The allWindows list in java.awt.Window contains references to some
old Dialogs which are created in step 2 and
 definitely have been dispose()d. This should remove the references
but apparently it doesn't.
 This works well with Xvnc as the backend.
 The attached screenshots from MemoryAnalyzer show that 12
FitLayerImpl objects are hanging in Memory, there should be only 1.
 The second shows the trace to the Heap root for one of them.

      Best regards
         Martin