arbitrary blank panel positions in module menu after dragging modules

[MStraeten]

Describe the bug

with new panel control several blank module positions occurs in the right module menu.
seems to occur if a module is moved by drag and drop (formerly this requested ctrl+shift) and additional blanks on further drag of a module (even the module keeps in its place)

unfortunately there doesn't seem to be a way to get rid of it/them again

Steps to reproduce

1. klick and drag a module in darkroom module menu

darktable version

4.9.0+501~g02a5e6b2f3-dirty

What OS are you using?

Mac

What is the version of your OS?

macos 14

[dterrahe]

Could you please try if #17467 helps? I can't test on Apple myself. The order gtk sends drag&drop messages seems to vary and might be completely different again on macos. Thanks!

[MStraeten]

the behaviour now occurs only if a module is shifted to a new pixel pipe position; then each shift results in a blank place above or below the shifted module.
so doesn't help ...

[dterrahe]

Could you please test for me if adding the && !below to the 3rd line of dtgtk_expander_set_drag_hover helps, so that it reads

  if(!widget || (!allow && !below && widget == _drop_widget && time == last_time)) return;

I suspect that on mac the last motion event, the drop event and the drag-end event are all delivered with the same timestamp, whereas for me (on debian and windows) they are always different, so I got away with the simpler check.

[MStraeten]

yes, that addition gives a proper behaviour