Cancelling a finished instance is nothing

source/FluxBase-Core-Tests/FBCancellationTest.class.st

@@ -983,3 +983,22 @@ FBCancellationTest >> testCancellingTheRemainingIterationsTakesAWaitingSubFlowWi
 	self assert: seen asArray equals: { #( nil nil ) }.
 	self assertConsistent: instance
 ]
+
+{ #category : 'tests' }
+FBCancellationTest >> testCancellingAFinishedInstanceIsNothing [
+	"a finished case is not cancelled after the fact: no trace, and it stays #done"
+	| flow instance before |
+	flow := self flowSplittingIntoTwoEnds.
+	instance := flow newInstance.
+	instance executeWith: 1.
+	self assert: instance state equals: #done.
+	self assert: instance hasEnded.
+	before := instance events size.
+
+	self assert: (instance cancel) isEmpty.
+
+	self assert: instance state equals: #done.
+	self deny: instance isCancelled.
+	self assert: instance events size equals: before.
+	self assertConsistent: instance
+]

source/FluxBase-Core/FBFlowInstance.class.st

@@ -1074,9 +1074,11 @@ FBFlowInstance >> cancel [
 	waits in me, and end - regardless of steps that failed before, an abort is a
 	decision. I read #cancelled from then on; a late signal or a second cancel is
 	silent. An instance that has not run yet gets its root scope for this - it has
-	been cancelled before it started, and says so"
+	been cancelled before it started, and says so. An instance that is over already -
+	done, or cancelled before - is left as it is: cancelling a finished case is
+	nothing, and it must not turn a #done into a #cancelled after the fact"
 
-	self isCancelled ifTrue: [ ^ #() ].
+	self hasEnded ifTrue: [ ^ #() ].
 	self ensureScope.
 	^ [ self cancelScope: scope ] ensure: [
 		(executor isNil or: [ self atEnd ]) ifTrue: [ self ended ] ]