Andreas Raab uploaded a new version of Kernel to project The Trunk:
http://source.squeak.org/trunk/Kernel-ar.415.mcz

==================== Summary ====================

Name: Kernel-ar.415
Author: ar
Time: 3 March 2010, 9:42:13.86 pm
UUID: dc49d9cd-b446-8747-8337-1712a9d0258f
Ancestors: Kernel-dtl.414

Attempt to complete ensure blocks that are currently under execution when terminating a process.

=============== Diff against Kernel-dtl.414 ===============

Item was changed:
  ----- Method: Process>>terminate (in category 'changing process state') -----
  terminate 
  	"Stop the process that the receiver represents forever.  Unwind to execute pending ensure:/ifCurtailed: blocks before terminating."
  
  	| ctxt unwindBlock oldList |
  	self isActiveProcess ifTrue: [
  		ctxt := thisContext.
  		[	ctxt := ctxt findNextUnwindContextUpTo: nil.
  			ctxt isNil
  		] whileFalse: [
  			(ctxt tempAt: 2) ifNil:[
  				ctxt tempAt: 2 put: nil.
  				unwindBlock := ctxt tempAt: 1.
  				thisContext terminateTo: ctxt.
  				unwindBlock value].
  		].
  		thisContext terminateTo: nil.
  		self suspend.
  	] ifFalse:[
  		"Always suspend the process first so it doesn't accidentally get woken up"
  		oldList := self suspend.
  		suspendedContext ifNotNil:[
  			"Figure out if we are terminating the process while waiting in Semaphore>>critical:
  			In this case, pop the suspendedContext so that we leave the ensure: block inside
  			Semaphore>>critical: without signaling the semaphore."
  			(oldList class == Semaphore and:[
  				suspendedContext method == (Semaphore compiledMethodAt: #critical:)]) ifTrue:[
  					suspendedContext := suspendedContext home.
  			].
+ 
+ 			"If we are terminating a process halfways through an unwind, try
+ 			to complete that unwind block first."
+ 			(suspendedContext findNextUnwindContextUpTo: nil) ifNotNil:[:outer|
+ 				(suspendedContext findContextSuchThat:[:c| c closure == (outer tempAt: 1)]) ifNotNil:[:inner|
+ 					"This is an unwind block currently under evaluation"
+ 					suspendedContext runUntilErrorOrReturnFrom: inner.
+ 				].
+ 			].
+ 
  			ctxt := self popTo: suspendedContext bottomContext.
  			ctxt == suspendedContext bottomContext ifFalse: [
  				self debug: ctxt title: 'Unwind error during termination']].
  	].
  !