rails/rails — pull request #13081 by mrreynolds (2013-11-27 19:55:12+00:00)
Title: Add port to default pid filename

This should make it easier for users to start multiple servers
with `rails server -p` in the same app directory without being
bumped by "A server is already running. Check /path/to/app/tmp/pids/server.pid".

Adding the port number to the pid's filename is a sensible and
unixy default IMHO.