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Cocoa - Odd behavior Drag and Drop between two Listboxes


I'm running into strange behaviour of TListbox in Cocoa in Trunk - seems to be there for a while already, as I had not updated Lazarus in a while and updated it just now to see if this happened to be fixed.

I have a simple form (example project attached), with 2 Listboxes.

Listbox1 is on the left en full form height. It has more rows than can be shown (eg. must scroll to see all rows).
Listbox1 has DragMode set to dmAutomatic.

Listbox2 is not full form height and has "Accept:=true" in the onDragOver event.

When dragging rows from Listbox1 to Listbox2, the cursor correctly changes to a "+" (and drag and drop works).
When scrolling Listbox1 however, it is as if the "area" that can receive rows in Listbox2 moved.

My Question of course: Did I goof up, or can anyone confirm this to be a bug?

Attached: Example project and screen recording - unfortunately, I was not able to upload a 150 KB MP4 screen recording (not allowed), or a 1 Mb animated GIF from that recording (too big), or a converted 2 Mb MPG file (also too big of course), so I zipped the MP4 file ...

Lazarus 2.3.0 (rev main-2_3-439-ga669e08450)
FPC 3.2.2 x86_64-darwin-cocoa
Intel Mac, macOS Monterey 12.2.1

Screencast shows that this is definitely a bug.

Thanks Alex. Reported it (link) at GitLab ... first report there for me, hope that went ok 😁


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