[SR-14894] Assertion failed: (!empty()) in ConstraintSystem::repairFailures

[ahoppen]

Previous ID	SR-14894
Radar	rdar://80271707
Original Reporter	@ahoppen
Type	Bug
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	Source Tooling
Labels	Bug, FoundByStressTester
Assignee	None
Priority	Medium

md5: 19b18351716ffb7dd45615ec21474275

is duplicated by:

• SR-15112 Assertion failed: (!empty()), function back, file SmallVector.h in ConstraintSystem::repairFailures

Issue Description:

The following test case hits an assertion failure !empty() in ConstraintSystem::repairFailures.

If a type annotation (icon: Category) is added to the closure parameter, the crash no longer happens.

// RUN: %sourcekitd-test -req=complete -pos=8:28 %s -- %s -sdk /Applications/Xcode-GPE.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS14.5.sdk -target arm64-apple-ios13.0

import SwiftUI

struct UserListFormView {
    @ViewBuilder var body: some View {
        let icons: [Category]
        ForEach(icons.map{ $0 }) { icon in
            Image(icon)
                .sag(icon)
        }
    }
}

enum Category: String {
    case housewares
}

extension View {
    func sag<V>(_ tag: V) -> some View where V : Hashable {}
}

[hborla]

Fixed by #39124