While [bug 1893645](https://bugzilla.mozilla.org/show_bug.cgi?id=1893645) was fixed some time ago now, it still shouldn't hurt to also assert that the `fontMatrix` is always valid when invoking the `compileGlyph` method.
While [bug 1893645](https://bugzilla.mozilla.org/show_bug.cgi?id=1893645) was fixed some time ago now, it still shouldn't hurt to also assert that the `fontMatrix` is always valid when invoking the `compileGlyph` method.