Spring Boot 4.2.0-M2 GraphQL Webflux stopped returning content length.

[SledgeHammer01]

Spring Boot 4.2.0-M2 (without changing ANYTHING else, reverting to M1 brings back content length)
Webflux
Netty 4.2.18.Final

On 4.2.0-M1 both successful and failed requests include the content length. On M2, the successful response is missing it (failed response includes it):

2026-09-24T16:21:08.259-07:00 ERROR 32272 --- [ main] o.s.t.w.r.s.ExchangeResult : Request details for assertion failure:

> POST http://localhost:8080/graphql
> WebTestClient-Request-Id: [1]
> Content-Type: [application/json]
> Content-Length: [1214]

{"query":"query IntrospectionQuery {\r\n    __schema {\r\n        queryType { name }\r\n        mutationType { name }\r\n        subscriptionType { name }\r\n        types {\r\n            kind\r\n            name\r\n            fields(includeDeprecated: true) {\r\n                name\r\n                args {\r\n                    name\r\n                    type { kind name ofType { kind name ofType { kind name } } }\r\n                    defaultValue\r\n                }\r\n                type { kind name ofType { kind name ofType { kind name } } }\r\n                isDeprecated\r\n                deprecationReason\r\n            }\r\n            inputFields {\r\n                name\r\n                type { kind name ofType { kind name ofType { kind name } } }\r\n                defaultValue\r\n            }\r\n            interfaces {\r\n                kind\r\n                name\r\n            }\r\n            enumValues(includeDeprecated: true) {\r\n                name\r\n                isDeprecated\r\n                deprecationReason\r\n            }\r\n            possibleTypes {\r\n                kind\r\n                name\r\n            }\r\n        }\r\n    }\r\n}\r\n"}

< 200 OK OK
< Content-Type: [application/json]
< Cache-Control: [no-cache, no-store, max-age=0, must-revalidate]
< Pragma: [no-cache]
< Expires: [0]
< X-Content-Type-Options: [nosniff]
< Referrer-Policy: [no-referrer]

{"data":{"__schema":{"queryType":{"name":"Query"},"mutationType":null,"subscriptionType":null,"types": ....

The response is correct otherwise. This is an introspection request, but I get the same thing on regular requests.

[SledgeHammer01]

It seems in M1 and earlier, the response goes through EncoderHttpMessageWriter, but in M2, it doesn't. FAILURE messages still go through EncoderHttpMessageWriter and have the content length.

[bclozel]

Superseded by spring-projects/spring-graphql#1533, thanks for the report @SledgeHammer01 .