Code review comment for lp:~widelands-dev/widelands/bug-1807156-heap-use-after-free

The reported line is:

./src/wui/buildingwindow.cc:359

which is

Widelands::Building* building_in_lambda = building_.get(parent_->egbase());

and my guess is that parent_ has become nullptr for some reason.

No idea how to test his - I did not manage to trigger the bug, but maybe somebody else will have more creative ideas.