Fixed #361: AttributeError in mailgun webhooks

[izimobil]

This fixes the case of delivery-status being None in the event data posted to mailgun webhook handler.
See: #361

[izimobil]

Hi, I realize I can reduce the raw_event in the test case to:

raw_event = mailgun_sign_payload(
    {
        "event-data": {
             "event": "accepted",
             "delivery-status": None,
        }
    }
)

Do you want me to update the PR ?

[medmunds]

Thanks for this. Yes, the shorter test case would probably be clearer. (Mailgun was one of Anymail's first integrations, so the existing tests tend to be more verbose than necessary.)

"delivery-status": null doesn't show up in Mailgun's event documentation. I wonder if there are any other undocumented changes to their webhook payloads?

[izimobil]

Thanks for this. Yes, the shorter test case would probably be clearer. (Mailgun was one of Anymail's first integrations, so the existing tests tend to be more verbose than necessary.)

OK !

"delivery-status": null doesn't show up in Mailgun's event documentation. I wonder if there are any other undocumented changes to their webhook payloads?

Well, to be honest, I don't know, we have a multi-tenant app, and the error showed up on a single tenant, probably a tenant with some weird MTA ?! I'll report the issue to mailgun !
Cheers

[medmunds]

(Released in Anymail 10.3)