Realm 5.0.0 filter not returning correct results

[Jaycyn]

Issue

Realm 5.0.0 filter not returning correct results when filtering on an objects List property.

Goals

Return the correct results

Expected Results

When filtering and there are 3 objects that match the filter, the results of the filter should contain 3 objects.

Actual Results

Sometimes the filter will return 1 result, other times two results, and rarely return all three results

Steps to Reproduce

A project with three Realm objects Account, Transaction and Item.

In brief:

AccountClass
  @objc dynamic var account_id = 1
   let transactionList = List<TransactionClass>()

TransactionClass
   @objc dynamic var account: AccountClass!

ItemClass
  let transactions = List<TransactionClass>()
  func printResultsCount() {
     let results = self.transactions.filter("account.account_id == 1")
     print(results.count) //sometimes prints 1, sometimes 2 and occasionally 3.

1. Create one AccountClass object, ensuring it's account_id = 1
2. Then we create three transactions and set their account property to that account class object
3. Lastly append the three transaction to the item's transactions list

The goal is to query the Item for all transactions where the transaction account number is 1

So as you can see we have a function in the item that should query for all transactions whose account property is an account where account_id = 1.

Sometimes the count is 1, sometimes 2, sometimes 3.

However, if we use a filter directly on the transactions, it outputs correctly

myButtonAction {
   let results = realm.objects(TransactionClass.self).filter("account.account_id == 1")
   print(results)
}

and will output 3 every time.

Code Sample

class AccountClass: Object {
    @objc dynamic var account_id = 0
    @objc dynamic var account_name = ""
    
    let transactionList = List<TransactionClass>()
    override static func primaryKey() -> String {
        return "account_id"
    }
}

class TransactionClass: Object {
    @objc dynamic var transaction_id = UUID().uuidString
    @objc dynamic var transaction_name = ""
    @objc dynamic var account: AccountClass!

    override static func primaryKey() -> String {
        return "transaction_id"
    }
}

class ItemClass: Object {
    @objc dynamic var item_id = UUID().uuidString
    @objc dynamic var item_name = ""

    let transactions = List<TransactionClass>()
    
    func printTransactions()  {
        self.transactions.forEach { trans in
            let id = trans.transaction_id
            let acct = trans.account.account_name
            let name = trans.transaction_name
            print(id, acct, name)
        }
    }

   func printFilteredResults() {
      let results = self.transactions.filter("account.account_id == 1")
      print(results.count) //1, sometimes 2, sometimes 3
   }
   
    override static func primaryKey() -> String {
        return "item_id"
    }
}

The two functions in the item class are just to for output testing. printTransactions prints the three transactions and the printFilteredResults should print the number of transactions that match the query.

Version of Realm and Tooling

Realm framework version: 5.0.0
Realm Object Server version: N/A
Xcode version: 11.3.1
iOS/OSX version: 10.14.x and 10.15.x
Dependency manager + version: N/A

[ejm01]

Thanks for the detail. I believe I've been able to replicate this and still looking into this further.