ModifyLogic before execution initialization fails with a null pointer

[carloea2]

Feature Summary

Root cause: the WebSocket handler checks that a workflow is attached, then dereferences an execution service that can still be null.

Before: a workflow is attached but execution has not started, then ModifyLogicRequest throws a NullPointerException.

Expected: the handler reports that workflow execution is not initialized and sends a WorkflowErrorEvent.

Reproduction evidence:

1. Attach a WebSocket session to a workflow without starting execution.
2. Send a ModifyLogicRequest frame.
3. Observe the NullPointerException.

A regression test against commit caeb27e reproduced this with 15 passing tests and 1 failing test.

Version and commit evidence:

1.3.0-incubating-SNAPSHOT on main

Commit Hash (Optional)
caeb27e

Browsers

Not browser specific.

Relevant log output

java.lang.NullPointerException

Proposed Solution or Design

Expected: the handler reports that workflow execution is not initialized and sends a WorkflowErrorEvent.

Affected Area

Workflow Engine (Amber)

[carloea2]

/take