SpringBoot Actuator content negotiation handles a single Accept header with multiple values incorrectly

When the underlying web framework returns a single value for the Accept header that contains a comma-separated list of values, the single-item list is made available to ProducibleOperationArgumentResolver. It does not handle it correctly as it treats the entire string as a single value rather than multiple comma-separated values.

Comment From: wilkinsona

Nope. MimeTypeUtils.tokenize(accept) takes care of this and the behaviour's covered by ProducibleOperationArgumentResolverTests.whenMultipleValuesAreAcceptableAsSingleHeaderThenHighestOrdinalIsReturned()