URL resolution breaks if route defined with lazy string and uses an include

[Andrea Angelini]

After this commit:

​https://github.com/django/django/commit/f920937c8a63df6bea220e4386f59cdb45b2e355

this is not working if self._route is gettext_lazy('test'):

        elif path.startswith(self._route):
            return path.removeprefix(self._route), (), {}

More info here:
​https://forum.djangoproject.com/t/gettext-lazy-and-url-patterns/43703

[Jacob Walls]

Thanks, replicated like this (traceback given in forum post):

from django.urls import path, include
from django.utils.translation import gettext_lazy as _

urlpatterns = [
    path(_(''), include("django.conf.urls.i18n"), name='index'),
]

It's documented that the route arg to path() can take a lazy string.

[Andrea Angelini]

Amended like following fixes this issue:

elif path.startswith(str(self._route)):
    return path.removeprefix(str(self._route)), (), {}

[Jake Howard]

I'd missed that lazy string were accepted, and surprised a test didn't cover this behaviour.

Just handling the elif case won't quite work, since there's also the endpoint case. Converting self._route to a string (as part of match, rather than the constructor so it's evaluated in the correct context) sounds like the right solution. It'd be nice if the conversion only happens once per match to avoid unnecessary extra work.

[Andrea Angelini]

I agree with you that it should be converted to a string as part of match and not as I proposed here

[Andrea Angelini]

In the endpoint seems accidentally to work though because gettext_lazy('test') == 'test' returns True, while
'test'.startswith(gettext_lazy('test')) and 'test'.removeprefix(gettext_lazy('test')) throw an error