Parallel tests add all tests to one partition if test durations are 0

This is really only particularly important if tests are miscalculated to take 0 seconds, which they have in the past.

In that case, all tests can be put in a single partition.

AFAIK, this is the sort of thing I think we want, modulo prejudices against lambda.

=== modified file 'testrepository/testcommand.py'
--- testrepository/testcommand.py 2011-11-01 15:24:36 +0000
+++ testrepository/testcommand.py 2012-01-10 16:34:01 +0000
@@ -208,10 +208,12 @@
         # Scheduling is NP complete in general, so we avoid aiming for
         # perfection. A quick approximation that is sufficient for our general
         # needs:
- # sort the tests by time
+ # sort the tests by time, and then by len of the partition's tests.
         # allocate to partitions by putting each test in to the partition with
         # the current lowest time.
- queue = sorted(timed.items(), key=operator.itemgetter(1), reverse=True)
+ queue = sorted(timed.items(),
+ key=lambda item: (item[1], -len(item[0])),
+ reverse=True)
         for test_id, duration in queue:
             timed_partitions[0][0] = timed_partitions[0][0] + duration
             timed_partitions[0][1].append(test_id)