> [snip] >
> You got the same (wrongish) results since you gave the sort the same order > in > the list. I can't recall how merge sort can freak out when given > conflicting > compares, I seem to recall that you might get an endless loop under some > circumstances as it orders and reorders the same group of objects. > This is all very interesting, no really it is, but it doesn't really answer the original question which is that given the same initial data in the same initial order and executing exactly the same code in the same release of Java produces different results. The only difference between the two executions is the fact that the test code executes in it's own instance of the JVM whereas the other execution runs in an instance shared with the container. I accept that the behaviour may be undefined even though it is consistently repeatable in both environments but surely given everything else being equal the results should be the same ... or maybe I'm just losing the plot. Lyallex