Of Jim Menard
> The comment for OrderedCollection>before:ifAbsent: states, in 
> part, "Answer 
> the result of evaluating the exceptionBlock if ... there are 
> no elements 
> before it."
> 
> The code, however, performs
> 	self errorFirstObject: target
> if the object is the first element of the collection.
> 
> Which should be changed: the code or the comment?

Patch 6159 in 3.9 has the fix (this can also be applied to 3.7) 
SequenceableCollection>>before: target ifAbsent: exceptionBlock
	"Answer the receiver's element immediately before target. Answer
	the result of evaluating the exceptionBlock if target is not an
element
	of the receiver, or if there are no elements before it."

	| index |
	index _ self indexOf: target.
	^ (index == 0 or: [index == 1])
		ifTrue: [exceptionBlock value]
		ifFalse: [self at: index - 1]