---
id: "bug-1438"
status: "fixed"
status_updated: "2026-09-24"
status_note: ""
component: "controller"
severity: "hang"
timestamp: "2026-07-14T09:36:00Z"
last_seen: "2026-09-19T09:00:00Z"
occurrences: 1
files: ["src/controller/testsuite/test_commit_barrier_rollout.c"]
tags: ["job-array-single-wal-record", "wal", "test-helper", "offset-arithmetic", "deadlock", "futex"]
related: []
legacy: true
---

# bug-1438: test_job_array_submit_appends_exactly_one_wal_entry_and_one_continuation: Expected 11 Was 5 (WAL…

## Description
test_job_array_submit_appends_exactly_one_wal_entry_and_one_continuation: Expected 11 Was 5 (WAL type mismatch); subsequent test hung all 3 threads on futex_do_wait

## Environment
_Not recorded (migrated from buglog.json)._

## Reproduction
_Not recorded (migrated from buglog.json)._

## Root cause
jap_read_last_wal_hdr()/jap_read_last_wal_payload() were copied from read_last_wal_hdr() in test_ha_role_lifecycle.c, which computes the header offset as seg_offset - sizeof(hdr). That arithmetic is only correct for zero-payload entries (its only prior caller was a WAL_NOOP test). Every WAL_JOB_ARRAY_SUBMIT entry carries a nonzero capnp payload, so seg_offset - sizeof(hdr) landed inside the payload bytes, not the header -- read garbage decoded as a bogus type (5 == WAL_JOB_STOP). The first array test's TEST_ASSERT_EQUAL_UINT32 failure then longjmp'd out of the test body BEFORE reaching jap_teardown(), leaking that test's persist_t (background WAL-sync thread still running) into the next test's jap_setup() memset -- corrupting a live mutex mid-flight and deadlocking all 3 threads on futex_do_wait in the very next test.

## Fix
Replaced the back-computed-offset helpers with jap_read_wal_hdr_at()/jap_read_wal_entry_at(), which take the entry's start offset EXPLICITLY. Callers now snapshot g_jap.seg_offset immediately before each persist_submit_job_array_async() call and pass that snapshot in, instead of trying to infer the header position from the post-append offset.

## Verification
_Not recorded (migrated from buglog.json)._

## References
_Not recorded (migrated from buglog.json)._