Problem Statement

When updating repository hook settings via the REST API, if the serialized settings exceed the hardcoded 32,768-byte LOB limit, Bitbucket returns an HTTP 500 Internal Server Error. The server logs correctly identify the validation failure (java.lang.IllegalArgumentException: The provided LOB data is too long), but this is not surfaced to the REST client.

This prevents automation and API consumers from distinguishing a "Payload Too Large" validation error from a transient server-side failure, leading to inappropriate retries.

Environment

• Product: Bitbucket Data Center

• Version: 9.4.19 (and likely all versions using InternalSharedLob)

• Database: Any (Limit is enforced at the application layer)

Steps to Reproduce

1. Install a repository hook that uses the standard settings persistence (e.g., a Java-based PreRepositoryHook).

1. Generate a valid JSON payload where a setting value causes the total serialized size to exceed 32,768 bytes.

• • Example: {{ {"largeValue": "A" * 33000}

    }}

1. Send a PUT request to the hook's configuration endpoint:
   PUT /rest/api/1.0/projects/{project}/repos/{repo}/settings/hooks/{hookKey}/enabled

1. Observe the HTTP response code and the server logs.

Expected Results

The REST API should return a client-side error:

• HTTP 413 Payload Too Large (Preferred, per RFC 9110) or HTTP 400 Bad Request.

• The response body should contain a machine-readable error message indicating that the LOB size limit was exceeded.

Actual Results

• HTTP Status: 500 Internal Server Error

• Response Body: Generic or empty.

• Server Logs:

 
 {{ c.a.s.i.r.e.DefaultUnhandledExceptionMapperHelper Unhandled exception while processing REST request java.lang.IllegalArgumentException: The provided LOB data is too long at com.google.common.base.Preconditions.checkArgument(Preconditions.java:143) at com.atlassian.stash.internal.setting.InternalSharedLob$Builder.data(InternalSharedLob.java:88) at com.atlassian.stash.internal.repository.InternalRepositoryHook$Builder.settings(InternalRepositoryHook.java:224)}}

Notes

This is not a request to increase the 32KB limit. It is a request to improve error handling so that the IllegalArgumentException thrown by InternalSharedLob$Builder is caught and mapped to an appropriate HTTP status code rather than falling through to the DefaultUnhandledExceptionMapperHelper.