Here are two patches for g_editor.c that fix following issues in 0.42.5:
1) undo recreates patch cords with wrong color (I posted this one earlier by mistake on the pd-list)
2) graph on parent (GOP) enable and then immediately disable crashes patches that haven't been closed prior to disabling GOP (to reproduce, open new patch->right-click->properties->enable gop->apply->disable gop->apply->crash). This one may also affect pd vanilla (haven't checked)
Best wishes,
ico