This handles the conditions when anchor values are larger than
LARGER_THAN_MAX_MESSAGE_ID by clamping them down to it. Also added
tests for the function parse_anchor_value.
Fixes#16768.
We raise MissingAuthenticationError now, which adds
`www_authenticate=session` header to the error response. This
stops modern web-browsers from displaying a login form everytime
a 401 response it sent to the client.
When user requests for a realm that doesn't exists, we raise
a InvalidSubdomainError.
This reduces our effort at repeatedly ensuring realm is valid
in request in web-public queries.
Via API, users can now access messages which are in web-public
streams without any authentication.
If the user is not authenticated, we assume it is a web-public
query and add `streams:web-public` narrow if not already present
to the narrow. web-public streams are also directly accessible.
Any malformed narrow which is not allowed in a web-public query
results in a 400 or 401. See test_message_fetch for the allowed
queries.