CREATE SUBSCRIPTION fails with long passwords

This made me a bit crazy tonight. Steps to reproduce:

1. Create a new role and give it a really long password. Ours was 108
chars.
2. Set up all the necessary replication permissions/roles.
3. From another computer, try to connect as that user using psql — it works!
4. Now try a CREATE SUBSCRIPTION command like:

create subscription my_sub connection 'host=192.168.0.111 port=5432
user=the_new_user password=long_password dbname=my_db sslmode=require'
publication new_server;

You'll get the following error:

ERROR: could not connect to the publisher: FATAL: password authentication
failed for user "the_new_user"

Now, go back and shorten that password, and try again. You'll get:

create subscription my_sub connection 'host=192.168.0.111 port=5432
user=the_new_user password=long_password dbname=my_db sslmode=require'
publication new_server;
NOTICE: created replication slot "my_sub" on publisher
CREATE SUBSCRIPTION

And it'll be off to the races. I watched the logs on both servers during
these experiments. Nothing much in there, aside from the logs above.

Is this known functionality? Seems like a nasty bug and it took me a while
to figure it out.

Thanks,

Mike