Levente Uzonyi uploaded a new version of Collections to project The Trunk:
http://source.squeak.org/trunk/Collections-ul.922.mcz

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

Name: Collections-ul.922
Author: ul
Time: 19 January 2021, 1:28:51.784086 pm
UUID: 7d688371-2966-43d3-9000-3985ae9f6afa
Ancestors: Collections-nice.921

Fix off-by-one errors in OrderedCollection's #removeFirst: and #removeLast:. The argument of those methods can be zero.

=============== Diff against Collections-nice.921 ===============

Item was changed:
  ----- Method: OrderedCollection>>removeFirst: (in category 'removing') -----
  removeFirst: n 
  	"Remove the first n objects into an array."
  
  	| lastIndexToRemove result |
+ 	n < 0 ifTrue: [ self errorNoSuchElement ].
- 	n < 1 ifTrue: [ self errorNoSuchElement ].
  	lastIndex < (lastIndexToRemove := firstIndex + n - 1) ifTrue: [ self errorNotEnoughElements ].
  	result := array copyFrom: firstIndex to: lastIndexToRemove.
  	array from: firstIndex to: lastIndexToRemove put: nil.
  	firstIndex := lastIndexToRemove + 1.
  	^result!

Item was changed:
  ----- Method: OrderedCollection>>removeLast: (in category 'removing') -----
  removeLast: n 
  	"Remove the last n objects into an array with last in last position."
  
  	| firstIndexToRemove result |
+ 	n < 0 ifTrue: [ self errorNoSuchElement ].
- 	n < 1 ifTrue: [ self errorNoSuchElement ].
  	(firstIndexToRemove := lastIndex - n + 1) < firstIndex ifTrue: [ self errorNotEnoughElements ].
  	result := array copyFrom: firstIndexToRemove to: lastIndex.
  	array from: firstIndexToRemove to: lastIndex put: nil.
  	lastIndex := firstIndexToRemove - 1.
  	^result!