Resolve 'NoneType' object has no attribute 'id'Traceback in django_mark_safe

[ehooo]

Fix NoneType exception when with statement don't contains as

[lukehinds]

thanks @ehooo , tested ok for me, you just ave a PEP8 violation to fix up:

E501 line too long (87 > 79 characters)
                    if getattr(withitem.optional_vars, 'id', None) == self.var_name.id:
                                                                               ^

[ericwb]

The changes look good. Can you please put more detail in the PR message. It's blank at the moment.