Fixes#3380.
The blueslip warning mentioned in #3380 were from paths ending at
people.email_list_to_user_ids_string. Some additional blueslip warnings
were raised after using that function.
Although we can put a validation check somewhere in the call stack of
people.email_list_to_user_ids_string, this function itself is used to
validate the operand by the higher order functions, so it wouldn't make
sense to put a validation check before that. Instead, removing the
blueslip warning altogether was chosen.
people.email_list_to_user_ids_string was replaced by
people.reply_to_to_user_ids_string which is a blueslip-free version
of the same. Other blueslip warnings were removed.
If atleast one of the private_message_recipients is invalid, compose
box will not be opened.
Thanks to Aastha Gupta <aastha.gupta4104@gmail.com> for some preliminary
work on this.
This run_test helper sets up a convention that allows
us to give really short tracebacks for errors, and
eventually we can have more control over running
individual tests. (The latter goal has some
complications, since we often intentionally leak
setup in tests.)
This takes advantage of the new function narrow_state.stream_id().
We now assume the incoming stream_id is a valid stream_id, so we
no longer need to test some of the error checking. (It's possible that
the incoming stream_id may no longer be for a stream you subscribe
to, but the nice benefit of working more in "id space" is that if
it doesn't match the narrow's stream id, we know false is a safe
return value.)