rspec/rspec-core — pull request #720 by sunaku (2012-10-30 19:33:20+00:00)
Title: add to exit status value if exit() already called

This commit fixes a problem that I introduced in pull request #569,
where RSpec won't run any specs if someone explicitly called exit().

This can also happen if someone was using both Test::Unit and RSpec
together and they had loaded RSpec before loading Test::Unit because in
that case, RSpec's at_exit handler would be registered before that of
Test::Unit. As a result, exit() called in Test::Unit's handler would
prevent RSpec from running any specs --- since $! would be SystemExit.