Index of insertion in backlinks is invalid

[nirinchev]

This is a Core issue based on the info I have from realm/realm-dotnet#3333.

It appears that the .NET SDK is receiving a change notification for a Results instance holding a backlinks view where the inserted index set contains the index 1, but the size of the collection is 1, which means the index is invalid.

For some context, the backlinks collection is constructed like:

TableView backlink_view = object.obj().get_backlink_view(table, column);
return new Results(object.realm(), std::move(backlink_view));

And we're subscribing for notifications like:

results->add_notification_callback(callback, std::make_optional(KeyPathArray()));

Upon receipt of the notification, we attempt to get the items which have been newly inserted, so we get an exception attempting to read an index larger or equal to the size of the `Results.

[nirinchev]

This is related to realm/realm-dotnet#3333 - the developer shared the relevant portions of their model in this comment: realm/realm-dotnet#3333 (comment).

[nicola-cab]

I'll try to reproduce the case and let you know.

[nicola-cab]

@nirinchev is this still relevant? Especially after #7830 ??

[nirinchev]

I don't know - it's a year-old issue that we didn't have an exact repro case for, so no way to verify if it's still a problem or not. Let's close and see if someone hits it again.