[SR-12662] Optional initializer for the .init() is not accepted

[swift-ci]

Previous ID	SR-12662
Radar	rdar://problem/62895055
Original Reporter	mstana (JIRA User)
Type	Bug
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	1
Component/s	Compiler
Labels	Bug
Assignee	mstana (JIRA)
Priority	Medium

md5: c976c9957f9cd93079042c559eebe65c

relates to:

• SR-10569 Compiler is confused when both dot syntax and forced unwrapping are used.

Issue Description:

When an optional initializer is supposed to be used compiler is complaining about the non-optional type.

The test can be performed in the playground by copy-paste this code:

struct Foo {
    let title: String
    init?(_ dictionary: [String: Any]?) {
        guard
            let title = dictionary?["title"] as? String
        else {
            return nil
        }

        self.title = title
    }


    static var `default`: Self {
        Self(["title": "default"])!
    }
}

func getNonOptionalFoo() -> Foo {
    .init(["title": "new default"]) ?? .default
}

Compiler error:

Value of optional type 'Foo?' must be unwrapped to a value of type 'Foo'

[beccadax]

@swift-ci create

[typesanitizer]

Reproduced with nightly on godbolt. Reduced example:

struct S {
    init?() { return nil }
}
func g() -> S { fatalError("AAA") }
func f() -> S {
    .init() ?? g() // error: value of optional type 'S?' must be unwrapped to a value of type 'S'
}

Note that using `S` explicitly (i.e. S.init()) fixes the issue.

[xedin]

Code from description type-checks correctly on main branch. mstana (JIRA User) please use the latest snapshot of main branch from swift.org to verify and close.