LinkingObjects empty for newly added objects

[humblehacker]

Goals

Access LinkingObjects on a new object added to a Realm.

Expected results

After adding an object with a LinkingObjects property to a Realm, accessing the LinkingObjects property returns the expected results.

Actual results

The LinkingObjects property returns no results. Note that if I use an object retrieved from a Realm rather than the original object added to the Realm, the LinkingObjects property works as expected.

Steps to reproduce

1. Define two Object classes with a bidirectional relationship, with a LinkingObjects property that points from child to parent.
2. Create one object of each class, and connect the child to the parent.
3. Create a Realm and add the parent object to it.
4. Access the LinkingObjects property on the child object.

Code sample that highlights the issue

Playground project

Version of Realm and Tooling

ProductName:	Mac OS X
ProductVersion:	10.13.3
BuildVersion:	17D47

/Applications/Xcode-9.2.app/Contents/Developer
Xcode 9.2
Build version 9C40b

/usr/local/bin/pod
Realm (3.1.0)
RealmSwift (3.1.0)

/bin/bash
GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin17)

/usr/local/bin/carthage
0.27.0
(not in use here)

/usr/local/bin/git
git version 2.16.1

[JettF]

I am experiencing this issue as well on Realm version 3.13.0

[maroony]

This bug is still present in 3.19.0. What's interesting: If you create a second child object and put it to the parent with the first child object, all is working as expected for the second child.

[amkomatz]

Any updates or workarounds for this? Our app is facing this issue in several places.

[amkomatz]

Okay, after further inspection, I can confirm that this is only happening on instances that were inserted into Realm. If you were to do a reload of that object, any LinkingObjects properties work fine. That appears to be the only workaround for now.

[ejm01]

I updated @humblehacker 's project to Swift 5, RealmSwift 4.4.1 and line 33 now shows expected results.

If anyone is still seeing the issue after 4.3.0 (#6834), please comment.