"pure virtual function call"/segfault when dragging the main toolbar

[Nazalassa]

This bug was found in Simutrans 124.2.2 Linux with the download from the official forum thread for version 124.2.2.

How to reproduce:

• Use any pakset
• Widen the Simutrans window so the toolbar comfortably fits (i.e the screen is much wider than the toolbar)
• Try dragging the toolbar, starting anywhere, and ending with the mouse cursor on a simple tool which button does not darken when active (e.g rotate map) the "rotate map" tool (which is the only one with which I found the bug to happen, maybe because it is the only one that alters the map?).

Expected result: the tool on which the cursor ends should be selected since the toolbar can't move.

Observed result: if the cursor ends on the "rotate map" tool (regardless of whether it is the last tool or not), Simutrans terminates with either (a) a segfault or (b) a "FATAL ERROR: unknown - pure virtual function call" accompanied with the following window:

[prissi]

THe rotation function seems broken, rereleasing 124.2.2