Using list with host parameter in blueprint.route() does not work.

[damianj]

Describe the bug
As the title implies, when I try to set the host parameter to a list on a blueprint route, the app does not start and instead gives an error like:

Traceback (most recent call last):
  File "test.py", line 16, in <module>
    parent_app.blueprint(child_bp)
  File "/usr/lib/python3.8/site-packages/sanic/app.py", line 757, in blueprint
    blueprint.register(self, options)
  File "/usr/lib/python3.8/site-packages/sanic/blueprints.py", line 146, in register
    route_names = [route.name for route in routes]
  File "/usr/lib/python3.8/site-packages/sanic/blueprints.py", line 146, in <listcomp>
    route_names = [route.name for route in routes]
AttributeError: 'NoneType' object has no attribute 'name'

Code snippet
To reproduce that error:

from sanic import Sanic, Blueprint
from sanic.response import text

child_bp = Blueprint(name='child_blueprint', url_prefix='/')
parent_app = Sanic(__name__)


@child_bp.route('/', host=["localhost:8000", "127.0.0.1:8000"])
async def hello_world(request):
    return text("Hello world!")

parent_app.blueprint(child_bp)
parent_app.run()

Note that if host is set to a string (i.e., @child_bp.route('/', host="127.0.0.1:8000")) or it's not even specified in the route (i.e., @child_bp.route('/')) then the app runs just fine.

Expected behavior
I would expect that the host parameter would function similar to that described in https://sanic.readthedocs.io/en/latest/sanic/routing.html#http-request-types

There is also an optional host argument (which can be a list or a string). This restricts a route to the host or hosts provided. If there is a also a route with no host, it will be the default.

Environment (please complete the following information):

• OS: Arch Linux (Kernel 5.4.13)
• Version: 19.12.2

Additional context
This was working previously so I don't know if it's a bug or some intentional change in functionality.

[damianj]

I've opened #1776 to address this issue.

[ahopkins]

Thanks for bringing this up.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. If this is incorrect, please respond with an update. Thank you for your contributions.

[myusko]

@ahopkins @ashleysommer probably we should close the issue since we already merged PR with a fix.