scala/scala — pull request #2869 by som-snytt (2013-08-23 07:46:18+00:00)
Title: https://github.com/som-snytt/scala/tree/issue/7775-sysprop-CME

I don't know why it didn't use my commit message... This is for visibility in case it's useful. It was fun just reading the code.

Just when you want to iterate over system properties in search
of a setting, someone else wants to configure their module by
setting a property.

Avoid ConcurrentModificationExceptions by iterating over property
names only, which are not backed by the underlying map.