Levente Uzonyi uploaded a new version of Collections to project The Trunk:
http://source.squeak.org/trunk/Collections-ul.783.mcz

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

Name: Collections-ul.783
Author: ul
Time: 5 March 2018, 10:52:44.810023 pm
UUID: 3cb7824b-9833-4ab9-bbac-66e36049b6ed
Ancestors: Collections-ul.782

WeakIdentityKeyDictionary changes:
- implemented #slowSize to be able to count of actually stored associations
- overridden #compact to cut tally back based on #slowSize
- compact the dictionary after removing unreferenced keys in #removeUnreferencedKeys

This all will ensure that if Undeclared is empty, then #isEmpty will return true after Smalltalk cleanOutUndeclared is executed.

=============== Diff against Collections-ul.782 ===============

Item was added:
+ ----- Method: WeakIdentityDictionary>>compact (in category 'private') -----
+ compact
+ 	"Reduce the size of array so that the load factor will be ~75%."
+ 	
+ 	| newCapacity |
+ 	tally := self slowSize.
+ 	newCapacity := self class goodPrimeAtLeast: tally * 4 // 3.
+ 	self growTo: newCapacity!

Item was added:
+ ----- Method: WeakIdentityDictionary>>removeUnreferencedKeys (in category 'as yet unclassified') -----
+ removeUnreferencedKeys
+ 	"Make sure tally is set to the right size by #compact."
+ 
+ 	super removeUnreferencedKeys.
+ 	self compact!

Item was added:
+ ----- Method: WeakIdentityDictionary>>slowSize (in category 'accessing') -----
+ slowSize
+ 	"Careful!! Answer the maximum amount
+ 	of elements in the receiver, not the
+ 	exact amount"
+ 
+ 	| count |
+ 	count := 0.
+ 	1 to: array size do: [ :index |
+ 		(array at: index) ifNotNil: [ :object |
+ 			object == vacuum ifFalse: [
+ 				count := count + 1 ] ] ].
+ 	^count!