JSON response may be truncated at 8192 bytes boundary

[pdolezal]

Describe the bug

A JAX-RS endpoint returns a Map instance to be serialized to JSON and returned. In some cases (I was not able to find the actual cause) the response returned to the client is truncated and does not contain the full JSON response.

The code behaves correctly with Quarkus 2.4.1, but when built with a newer version (tried 2.5.1 and 2.6.2), it produces the truncated response. I was able to reproduce the behavior reliably on different systems (Oracle on Windows, Eclipse Temurin on Alpine) with the given example. The interesting thing is that even small changes of the response may cause the response to be rendered correctly. I could not figure out the reason for the behavior. A notable point is that the response chunk that is returned, has 8192 bytes.

Expected behavior

The response returned by the reproducing example should be complete, not truncated.

Actual behavior

The example returns the truncated response, which is truncated at 8192 bytes (ends with {"fileName":"tome2.pdf","modifiedAt":"2021-12-14T09:53:).

How to Reproduce?

1. Build the example mvn clean package, JDK 17 assumed (toolchains profile may be used to choose the JDK if toolchains is configured).
2. Run the example application.
3. Get the response: curl --request GET --url http://localhost:8080/objects

Changes in the POM file's quarkus.version property may deliver different results as noted, the correct behavior should be observed when the property is changed to 2.4.1.

cut-off-bug.zip

Output of uname -a or ver

Microsoft Windows [Version 10.0.19043.1415]

Output of java -version

Java HotSpot(TM) 64-Bit Server VM (build 17.0.1+12-LTS-39, mixed mode, sharing)

GraalVM version (if different from Java)

No response

Quarkus version or git rev

2.6.2

Build tool (ie. output of mvnw --version or gradlew --version)

Apache Maven 3.8.2 (ea98e05a04480131370aa0c110b8c54cf726c06f)

Additional information

As noted in the description, the problem was observed for the first time with the original code in Docker based on eclipse-temurin:17-alpine.

[stuartwdouglas]

Seems to have been introduced by 627e127 , although I think this may have been an existing problem that has just been uncovered by this.