Use-case

As a developer, I want to develop with missing binary/image files

It is it seems quite customary to run eZ Publish with out-of-sync database & vardir in dev mode. This was hotfixed dirtily in the past (EZP-20502), but should be handled better, as a real feature.

Specification

A TolerantIOService encapsulates the original. It will ignore NotFound errors from the handlers, and return MissingBinaryFile objects when applicable so that callers can operate as expected (this isn't ideal, but it is pretty much what was happening, in a dirtier way, until then).