STR:

1. Start with MOZ_ENABLE_WAYLAND=1 on Ubuntu 22.10.
2. Create nested bookmark toolbar folders filled with many items that have long names so the popups are large.
3. Try dragging a bookmark out of a deeply nested folder to a higher level or to a destination behind the popup.

The parent folder popups stay open while dragging which can obstruct much of the screen, nested folders can overlap and hide higher levels due to screen limits. If the destination is obstructed then it is not possible to drag and drop to that location.

Maybe we can hide the popup only visually and remove the platform special-case? Using visibility: hidden; and pointer-events: none; in CSS rather than hidePopup.

(In reply to Emilio Cobos Álvarez (:emilio) from comment #1)

Maybe we can hide the popup only visually and remove the platform special-case? Using visibility: hidden; and pointer-events: none; in CSS rather than hidePopup.

How can that help? The source surface must be visible. Only fix is to change the Wayland D&D protocol.

Hmm, does visibility: hidden in CSS really hide the widget? I would expect not (since that can still cause visibility: visible content underneath to show. So I was under the impression that it'd just effectively make all their contents not paint (so the surface would be considered visible)