CodeQL alert #25 (go/duplicate-branches) on internal/api/handler/
acme.go::ACMEHandler.Account flagged that 'if readOnly { ... } else
{ ... }' had byte-identical bodies — both setting the same
Content-Type: application/json header. The 'readOnly' bool was
threaded through the function as a placeholder for differentiated
headers (Cache-Control etc. on the POST-as-GET path) that never
landed; both branches collapsed to the same value with no
follow-through.
Audit + fix:
- The alert is real (verified by re-reading the source); not a
false positive.
- The Copilot Autofix Anthropic surfaced was correct in spirit but
incomplete: it collapsed the if/else but left 'readOnly' as
dead code (declared at line 395, assigned at lines 400 and 436,
only read at the now-removed if). golangci-lint's 'unused'
linter would flag 'readOnly' next.
- Complete fix: collapse the if/else AND remove the now-unused
'readOnly' variable + its 2 assignments. Single unconditional
'w.Header().Set("Content-Type", "application/json")' covers
both paths (RFC 8555 §6.3 POST-as-GET + §7.3.2 / §7.3.6 update
+ deactivation all return the same account JSON shape — no spec
rationale for differentiating headers).
Verified locally: 'gofmt -l .' clean; 'go vet ./...' clean;
'go test -short -count=1 ./internal/api/handler/' green; 'grep
readOnly' on the file returns only the new explanatory comment
(no live references).
The alert was first detected in commit 44a85d6 (Phase 1b) — the
duplicate has been sitting in the codebase since the Account
handler shipped. No functional regression for any RFC 8555 client
(cert-manager, lego, Posh-ACME): same status code, same headers,
same body.
shankar0123
650f5a198f