Issue 1565: [FIX] Improve performance of weak key dictionaries When Martin von Loewis visited SCG in 2007, he did some nice enhancements to weakkeydictionaries... The problem is that they are re-hashed far to often (when a nil key is found, which happens frequently if the keys are garbagecollected often...) For me, this change translates to a ca. 20% improvement in Monticello performance. Original bug report: 0006348: [FIX] Improve performance of weak key dictionaries http://bugs.squeak.org/view.php?id=6348 Marcus