Clarify a case optimisation.
Clarify a case optimisation.

Ignore-this: 619b56c41e2e94f05985a425a18c6381

darcs-hash:20081123051318-26c35-725b6280e1e6bfa0dc1a24e4e34b1b9c8984d7a2

jimcrayne/jhc,jimcrayne/jhc,jimcrayne/jhc,jimcrayne/jhc