RxJavaErrorHandler does not get invoked when onErrorResumeNext/onErrorReturn/... are involved

[mattrjacobs]

The RxJavaErrorHandler only gets invoked in SafeSubscriber._onError(ex). Given the use of operators as of RxJava 0.17.x, onErrors caught and handled by the onErrorResumeNext/onErrorReturn/... patterns don't propagate out to SafeSubscriber, and never get handled.

[abersnaze]

One of solutions that we came up with was to add logic to onError.*() methods to report the errors to the plugin before allowing the closure the chance to ignore them. I'm not a fan of this one because it could lead to double reporting of errors.

error(new Exception()).onErrorResumeNext(e -> concat(just(null), error(e)))

Another idea was to wrap the invocation of all user code to handle exceptions in a consistent way across of the Rx codebase. This would be a huge change and makes the assumption that the Rx code is prefect with regards to exception handling. As an experiment I changed the signature of Func0...N and Action0...N to call(...) throws Throwable and was greeted with thousands of errors. There are lots of places where an operator invokes a closure without garding against it failing.

[mattrjacobs]

Now tracked by Pull Request #1306

[benjchristensen]

Done in #1306