Tobias Pape uploaded a new version of Collections to project The Trunk:
http://source.squeak.org/trunk/Collections-topa.565.mcz

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

Name: Collections-topa.565
Author: topa
Time: 25 March 2014, 2:28:36.459 pm
UUID: b7c264b3-1e69-494d-8979-6f71bc9b846d
Ancestors: Collections-ul.564

When a stream is created on a collection, it tries to keep
using that collection instead of copying, even in the case
of mutation of the original collection.

The code removed prevented this.

=============== Diff against Collections-ul.564 ===============

Item was changed:
  ----- Method: WriteStream>>nextPut: (in category 'accessing') -----
  nextPut: anObject 
  	"Primitive. Insert the argument at the next position in the Stream
  	represented by the receiver. Fail if the collection of this stream is not an
  	Array or a String. Fail if the stream is positioned at its end, or if the
  	position is out of bounds in the collection. Fail if the argument is not
  	of the right type for the collection. Optional. See Object documentation
  	whatIsAPrimitive."
  
  	<primitive: 66>
- 	((collection class == ByteString) and: [
- 		anObject isCharacter and:[anObject isOctetCharacter not]]) ifTrue: [
- 			collection := (WideString from: collection).
- 			^self nextPut: anObject.
- 	].
  	position >= writeLimit
  		ifTrue: [^ self pastEndPut: anObject]
  		ifFalse: 
  			[position := position + 1.
  			^collection at: position put: anObject]!