Single.takeUntil does not dispose subscription to 'other' upon disposal

[damianw]

Using Single.takeUntil does not dispose the subscription it makes to other when the main subscription is disposed. RxJava Version: 2.1.13

Sample

val control = Single.never<Nothing>()
        .doOnSubscribe { println("Subscribe control") }
        .doOnDispose { println("Dispose control") }
val disposable = Single.never<Nothing>()
        .doOnSubscribe { println("Subscribe main") }
        .doOnDispose { println("Dispose main") }
        .takeUntil(control)
        .subscribe()
disposable.dispose()

prints only:

Subscribe control
Subscribe main
Dispose main

Comparison with Observable

For comparison, Observable.takeUntil:

val control = Observable.never<Nothing>()
        .doOnSubscribe { println("Subscribe control") }
        .doOnDispose { println("Dispose control") }
val disposable = Observable.never<Nothing>()
        .doOnSubscribe { println("Subscribe main") }
        .doOnDispose { println("Dispose main") }
        .takeUntil(control)
        .subscribe()
disposable.dispose()

prints:

Subscribe control
Subscribe main
Dispose main
Dispose control

[akarnokd]

Thanks for reporting. This is indeed a bug with Single.takeUntil(Single) and with a bunch of other variants. I'll post a fix shortly.

[akarnokd]

Fix posed in #6019. Since the whole Single.takeUntil is bugged, the workaround is to convert both to Observable for the duration of the call:

val control = ...

val main = ...

main.toObservable().takeUntil(control.toObservable()).singleOrError()