Swift/Collection.swift:722: Fatal error: Index out of bounds

Question

Volker Runkel OP

Created Apr ’23

Replies 4

Boosts 0

Participants 2

Hello,

I have a simple SwiftUI app for macOS. It uses CoreData as data storage. I have a @FetchRequest and use the resulting array to populate a Table. I have added .searchable to have a search field. I usually can search without problems. Yet, some valid search strings result in a crash repeatedly giving:

Swift/Collection.swift:722: Fatal error: Index out of bounds

The crash happens in the main thread and the call stack is buried within refresh code for the table. It happens after [NSTableView _delegate_isGroupRow:] is called .

This is a big show stopper and I have no possibility to interfere since it happens in code out of my control. ´

My table code is without sections and simple like this:

var table: some View {
        Table(selection: $selection, sortOrder: $items.sortDescriptors) {
            TableColumn("Authors", value: \.authorsForDisplay!).width(min:30, ideal:50, max:200)
            TableColumn("Title", value: \.title!).width(min:100, ideal:300, max:500)
            TableColumn("Year", value: \.year) { article in
                Text(String(article.year))
            }.width(min:50, ideal:50, max:50)
            TableColumn("Journal") { article in
                Text(article.journal?.name ?? "---")
            }.width(min:30, ideal:50, max:200)
            TableColumn("Publisher") { article in
                Text(article.publishedBy ?? "---")
            }.width(min:30, ideal:50, max:200)
        }
    rows: {
        ForEach(items) { article in
            TableRow(article)
        }
    }}

Any ideas?

Thx, Volker

Boost

Answer 1

Claude31 OP

Apr ’23

Please give more information.

Where do you use search string ?
how do you populate array
Give an example of failing search string and successful one
where does the crash occur (show refresh code for the table)
or at least the value of index out of bounds and the number of items in Table

.

it happens in code out of my control

What do you mean ? Out of your own code ?

0

Answer 2

Volker Runkel OP

Apr ’23

Thx!

I get the string entered in a search field (created using .searchable() )

Upon submission of the search (by pressing enter) I call a function:

private func searchPredicate(query: String) {
        if self.searchControl.originalPredicate == nil {
            self.searchControl.originalPredicate = items.nsPredicate
            if items.nsPredicate == nil {
                self.searchControl.originalPredicate = NSPredicate(format: "TRUEPREDICATE")
            }
        }
        var predicate: NSPredicate?
        if self.searchScope == .title {
            predicate = NSPredicate(format: "%K CONTAINS[cd] %@", #keyPath(Article.title), self.searchText)
        } else if searchScope == .authors {
            predicate = NSPredicate(format: "%K CONTAINS[cd] %@", #keyPath(Article.authorsForDisplay), self.searchText)
        }
        DispatchQueue.main.async {
            self.items.nsPredicate = NSCompoundPredicate(andPredicateWithSubpredicates: [self.searchControl.originalPredicate ?? NSPredicate(format: "TRUEPREDICATE"), predicate!])
        }
    }

When calling this line: self.items.nsPredicate = NSCompoundPredicate(andPredicateWithSubpredicates: [self.searchControl.originalPredicate ?? NSPredicate(format: "TRUEPREDICATE"), predicate!])

The crash will occur - or as often - not.

This works for most search string. Only some strings repeatedly cause the mentions crash. for example if I enter wasser it crashes. If I enter bat or evident or turbine or curtail or... it doesn't.

All valid and normal strings. Searches with zero results work as well, so entering xcojfoesjif will not give a crash. So far I can reproduce the crash using washer or human - I have not tried more words yet.

When I look at the call stack, it happens within private functions handling the Table display. There is no refresh code for the table since the the following fetch request is used - and it does automatically pre-render the view (as a @State would do):

@FetchRequest(
        entity: Article.entity(), sortDescriptors: [NSSortDescriptor(keyPath: \Article.year, ascending: false)], predicate: NSPredicate(format: "TRUEPREDICATE"), animation: .default)
    private var items: FetchedResults&lt;Article>

I do not have a single line where I rely on an index for the data array. All done magically by SwiftUI. Otherwise it would be easy to solve ;)

The code is on Github: https://github.com/vrunkel/Peru

I can also supply my test data which needs to be imported from xml first.

To me it looks like a bug in SwiftUI's table implementation. Since the call stack contains _delegate_isGroupRow: before the crash, I wonder if for some reason the table wants to create sections? I don' have sections as seen in the code sample above regarding table display.

Hope that clarifies!

0

Answer 3

Claude31 OP

Apr ’23

Just to check, try to replace

DispatchQueue.main.async

by a

asyncAfter

to delay 1 second

And tell what you get

0

Answer 4

Volker Runkel OP

Apr ’23

After updating to Ventura 13.3 the error is gone. So as expected, internal bug. Happy.

0