Crash in InAppMessageBannerViewController.handleBannerConstraints(size:) in 19.0.0

[neriusv]

We're seeing a crash in InAppMessageBannerViewController.handleBannerConstraints(size:):

Unable to activate constraint with anchors <NSLayoutXAxisAnchor:0x303e8ca40 "_TtGC7SwiftUI14_UIHostingViewV17AirshipAutomation22InAppMessageBannerView_:0x10aa96400.centerX"> and <NSLayoutXAxisAnchor:0x303e8ca00 "UIWindow:0x108c0e540.centerX"> because they have no common ancestor. Does the constraint or its anchors reference items in different view hierarchies? That's illegal.

Stack trace:

          Fatal Exception: NSGenericException
0  CoreFoundation                 0x83f20 __exceptionPreprocess
1  libobjc.A.dylib                0x172b8 objc_exception_throw
2  CoreAutoLayout                 0xc454 -[NSLayoutConstraint isActive]
3  <APP>                          0x1120408 InAppMessageBannerViewController.handleBannerConstraints(size:) + 116 (InAppMessageHostingController.swift:116)
4  <APP>                          0x111f904 closure #2 in InAppMessageBannerViewController.viewDidAppear(_:) + 94 (InAppMessageHostingController.swift:94)
5  Combine                        0xaecc Subscribers.Sink.receive(_:)
6  Combine                        0xae60 protocol witness for Subscriber.receive(_:) in conformance Subscribers.Sink<A, B>
7  Combine                        0x3d940 PublishedSubject.Conduit.offer(_:)
8  Combine                        0x3d600 partial apply for closure #1 in PublishedSubject.send(_:)
9  Combine                        0x12f50 ConduitList.forEach(_:)
10 Combine                        0x12060 PublishedSubject.send(_:)
11 Combine                        0x11bd4 static Published.subscript.setter
12 <APP>                          0x11170f4 closure #1 in closure #1 in InAppMessageBannerView.banner.getter + 193 (InAppMessageBannerView.swift:193)
13 <APP>                          0x58614 thunk for @escaping @callee_guaranteed @Sendable () -> () (<compiler-generated>)

Started happening after upgrading to Airship 19.0.0.

It's a production crash, not sure how to reproduce, but it might be related to displaying several in-app messages in a row.

[rlepinski]

What SDK version did you come from? Pretty sure this was probably introduced in this commit - c6be6d3

Could you answer a few questions, might help with reproducing:

• Is your app UIKit or SwiftUI?
• Do you have metrics you can share on the crash?
  • OS versions
  • Number of crashes
  • Percent of audience crashing

Ill try to to stress test it to reproduce the issue. I am pretty sure we are just trying to update constraints during some sort of transition instead of doing it on viewDidLayoutSubviews.

[rlepinski]

I was not able to reproduce the issue in our sample, but I was able to do it with a minor code change:

    override func viewDidDisappear(_ animated: Bool) {
        // Added this line
        self.bannerConstraints.size = CGSize(width: 100, height: 100)

        super.viewDidDisappear(animated)
        subscription?.cancel()
    }

Canceling the subscription in viewWillDisappear fixes it. Ill try to get a patch out ASAP.

[rlepinski]

Fixed in 19.0.2. Pod and SPM have been updated. XCFrameworks next week hopefully