[SR-419] Property observers not triggered on other instances of same class

[swift-ci]

Previous ID	SR-419
Radar	rdar://problem/32334826
Original Reporter	andyvn22 (JIRA User)
Type	Bug
Status	Closed
Resolution	Done

Additional Detail from JIRA

Votes	2
Component/s	Compiler
Labels	Bug
Assignee	@hamishknight
Priority	Medium

md5: 95314f70fefe4dcd9b362a8cdb300328

Issue Description:

Property observers are not triggered from observers on other instances of the same class:

class Thing {
    var related: Thing?
    var observerCalled = false
    var property: String = "Initial" {
        didSet {
            observerCalled = true
            related?.property = property //should trigger related's observer
        }
    }
}

let thing = Thing()
thing.related = Thing()
thing.property = "New Value"
print("thing observer called: \(thing.observerCalled) [expected true]") //true
print("related observer called: \(thing.related!.observerCalled) [expected true]") //false

[belkadan]

Ugh. We really need to check that the base of the property access is statically self.

[hamishknight]

#15280

[hamishknight]

Resolved in the above linked PR, and will take effect in Swift 5 mode.

[AnnaZaks]

andyvn22 (JIRA User), Could you verify if the problem is fixed and if so move the JIRA to "Closed"?
Thanks!
Anna