Corey

> The ParseSwift library does not have a clear migration path from this library For anyone who's looking to switch from the Objective-C SDK to the Swift SDK, you should...

Can you provide an example of how to reproduce this error?

This may be related to #1588. My suggestion would be to port the test cases I listed first (in this PR), then if that utility method is broken, add the...

Eyeballing android, it seems to have may the batch count issue also https://github.com/parse-community/Parse-SDK-Android/blob/a5cfa1f9c6654281c76367ad8b3252e2499bb821/parse/src/main/java/com/parse/Lists.java#L67

Can you rebase this with the master branch to run the CI? Also, it sounds like you have a possible testcase to verify your bug fix, can you add that...

> Does my explaination of the flaw in the algorithm make sense though? The explanation makes sense, but I need to think more if the case you presented should work...

@dplewis @mtrezza @TomWFox what do you all think? This was also brought up in the Android repo. Sounds like it can be a big problem. The questions I have is...

> No circular dependencies. This call should succeed in both cases, with or without my fix, but without my fix parent and all it's children will be visited twice, with...

Two objects attempting to point to the same object that is unsaved and therefore not unique can cause a problem

If PFObjects were structs and equatable then there probably wouldn’t be an issue with this, but they are not here