This change is coming from Doug Lea's CVS and I've already review it.
It seems that in the re-work that was done for Java 7 we dropped this corner case.
STPE.delayedExecute will add the task to the work queue and invoke prestartCoreThread. But prestartCoreThread checks for the worker count (0) being less than corePoolSize (0) and as that is not the case nothing happens. So we have a task in the queue but no thread waiting to execute it.
For STPE when the queue is not empty there must always be at least one thread waiting on the queue.
http://cr.openjdk.java.net/~chegar/7091003/webrev.00/webrev/ -Chris.
