`@Contract` for `StreamUtils.drain()` incorrectly declares `null` results in an exception

[sbrannen]

Overview

Although the implementation of org.springframework.util.StreamUtils.drain(InputStream) originally threw an IllegalArgumentException for a null InputStream, since commit 0b9b9b4 drain() returns 0 for a null stream.

Consequently, the @Contract("null -> fail") declaration is incorrect.

Related Issues

• StreamUtils.copyRange overreads source stream in some cases #32695