[NotificationsViewController.selectRow] NSInternalInconsistencyException: Attempted to perform update with invalid index path: <NSIndexPath: 0x283a1b9a0> {length = 2, path...

[jkmassel]

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Sentry Url: https://sentry.io/share/issue/0fdb6fedd3d44625bf944ffb7c306193/ User Count: 616 Count: 803 First Release: 14.8.0.3 First Seen: 2020-09-04T04:34:54Z Last Seen: 2020-11-23T18:22:01Z 24 Hours: 216 30 Days: 763

NSInternalInconsistencyException: Invalid indexPath
  File "NotificationsViewController.swift", line 910, in NotificationsViewController.selectRow
  File "NotificationsViewController.swift", line 211, in NotificationsViewController.traitCollectionDidChange
  File "<compiler-generated>", line null, in NotificationsViewController.traitCollectionDidChange
  File "main.swift", line 7, in main
...
(70 additional frame(s) were not displayed)

[leandroalonso]

@jleandroperez pinging you here cause you're our notifications master, sir!

I was thinking that perhaps we can just check if the indexPath is valid before updating it? I'm just not sure if that would leave the app in a weird state somehow. Thoughts?

[jleandroperez]

@leandroalonso Hey there!! long time no see!!

As far as I understand, it's crashing in this API right?

    func selectRow(for notification: Notification, animated: Bool = true,
                   scrollPosition: UITableView.ScrollPosition = .none) {
        selectedNotification = notification

        if let indexPath = tableViewHandler.resultsController.indexPath(forObject: notification), indexPath != tableView.indexPathForSelectedRow {
            DDLogInfo("\(self) \(#function) Selecting row at \(indexPath) for Notification: \(notification.notificationId) (\(notification.type ?? "Unknown type")) - \(notification.title ?? "No title")")
            tableView.selectRow(at: indexPath, animated: animated, scrollPosition: scrollPosition)
        }
    }

Invalid Index Path makes me think that the resultsController.indexPath(forObject:) invocation succeeds, but the TableView is unaware of such path.

I'd say that the table (for whatever reason) got Out of Sync with the NSFetchedResultsController. I would suspect of:

• This method being executed in a BG thread?
• A reloadData invocation happening somewhere

Note that, it's possible, at that point the TableView is already in a broken state. You could probably detect such scenario (by checking if the IndexPath is out of bounds), and, as you mentioned, perhaps invoke reloadData.

P.s.: Mother of god, when did this ViewController get 1800 LOC!!!

[designsimply]

Raising to high priority because it's showing a high number of users affected. I don't think it's a new issue though 🤔 I think this issue is a continuation of https://github.com/wordpress-mobile/WordPress-iOS/issues/15092 which came to a full stop on Nov 20 and this one picked up steam at the exact same time. Something seems to have gotten rejiggered in Sentry.

Events in the last 90d: 4,300 Users affected in the last 90d: 2,300 _{WORDPRESS-IOS-38WR: https://sentry.io/share/issue/0fdb6fedd3d44625bf944ffb7c306193/}

[salimbraksa]

This issue was addressed in this PR, but the fix resulted in a new bug:

• NSInternalInconsistencyException: Requested the number of rows for section (2) which is out of bounds.

The app crashes in selectRow method, likely due to an attempt to get the number of rows of a section that doesn't exist.

tableView.numberOfRows(inSection: indexPath.section)

I think the app crashes if the given indexPath.section doesn't exist.

I've assigned you this issue @dvdchr since you've worked on it before, but feel free to un-assign yourself if you're not planning to continue working on it.

[jkmassel]

This only happens in very old versions of the app, so it can be closed.