Florian Müllner authored Sep 03, 2018 and Philip Chimento committed Sep 12, 2018

JS classes accept names that aren't valid GType names. Usually this
is something the programmer can take into account, however sometimes
a parent class isn't under their control and can therefore change
unexpectedly (gnome-shell extensions are a primary example).

Handle this case gracefully by replacing any invalid characters with
underscores.

!229