Eliot Miranda uploaded a new version of Tools to project The Trunk:
http://source.squeak.org/trunk/Tools-eem.984.mcz

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

Name: Tools-eem.984
Author: eem
Time: 16 July 2020, 3:10:24.240422 pm
UUID: c9cea967-9685-4ce3-8eea-72da87f12be6
Ancestors: Tools-mt.983

Fix a regression in Tools-ct.952.
This fix constitutes a review of http://forum.world.st/BUG-in-Debugger-gt-gt-newStack-optimization-td5112726.html

=============== Diff against Tools-mt.983 ===============

Item was changed:
  ----- Method: Debugger>>newStack: (in category 'private') -----
  newStack: stack
+ 	| oldStack diff matchIndex |
- 	| oldStack diff |
  	oldStack := contextStack.
  	contextStack := stack.
+ 	(oldStack isNil or: [oldStack last ~~ stack last]) ifTrue:
+ 		[contextStackList := stack collect: [:ctx | ctx printString].
+ 		 ^self].
- 	(oldStack == nil or: [oldStack last ~~ stack last])
- 		ifTrue: [contextStackList := contextStack collect: [:ctx | ctx printString].
- 				^ self].
  	"May be able to re-use some of previous list"
  	diff := stack size - oldStack size.
  	contextStackList := diff <= 0
+ 		ifTrue: [contextStackList copyFrom: 1 - diff to: oldStack size]
+ 		ifFalse:
+ 			[matchIndex := stack lastIndexOf: oldStack first startingAt: diff + 1.
+ 			 matchIndex = 0
+ 				ifTrue: [contextStack collect: [:ctx | ctx printString]]
+ 				ifFalse: [((contextStack first: matchIndex - 1) collect: [:ctx| ctx printString]), contextStackList]]
+ 						"#(d e f h i) => #(a b c d e f g h i)
+ 						diff := 3.
+ 						matchIndex := 4.
+ 						#(a b c d e f g h i) := #(a b c), #(d e f h i)"!
- 		ifTrue: [contextStackList copyFrom: 1-diff to: oldStack size]
- 		ifFalse: [(diff = 1 and: [stack second == oldStack first])
- 			ifTrue: [contextStackList copyWithFirst: stack first printString]
- 			ifFalse: [contextStack collect: [:ctx | ctx printString]]]!