fix(httpx): close request-body completion race in egress recorder

[Desperado]

What broke

CI on main (release: v1.22.2) went red on a single test:

internal/httpx  TestRecordsRequestHashAndSize
  httpx_test.go:77: req_bytes = 0, want 7000
  httpx_test.go:81: req_sha256 = "", want "3e5a27be…"

(The tar: Cannot open: File exists spam and the QualityMax report failed (HTTP 401) line in that run are unrelated, non-fatal noise from the cache-restore and reporting steps.)

The test passes locally at that exact commit, including -count=500, -race, and -cpu=1 — it's a timing flake, not a regression.

Root cause

net/http writes the request body on a separate goroutine and returns from RoundTrip as soon as the response headers arrive. receiptTransport.RoundTrip read hashingBody.complete synchronously right after RoundTrip returned, so on a loaded runner it could snapshot mid-write — before the body-write goroutine had read the body through io.EOF and set complete. Result: a fully-sent body recorded as incomplete (ReqBytes=0, ReqSHA256="", request-body-incomplete note).

This is mostly a flaky test, but the same window could occasionally under-report real egress metadata in the receipt.

Fix

A conformant RoundTripper always closes req.Body after the write settles (including the final EOF read). So hashingBody now closes a closed channel on Close(), and on a successful round trip RoundTrip waits on it (bounded by the request context, which the client Timeout cancels) before snapshotting. Transport-error and no-body paths are unchanged; the genuine "server responded before consuming the body" case still records incomplete, because Close still fires with complete == false.

Tests

• TestFullBodyRecordedWhenTransportFinishesWritingAfterResponse — deterministic: models net/http's async-write ordering with a fake transport that closes the body after RoundTrip returns. Reproduces the exact CI symptom (bytes:0 hash:"") without the barrier and passes with it.
• TestConcurrentRealRequestsRecordCompleteBody — 64 concurrent real-loopback requests, each asserting a complete byte count + hash.
• Updated TestIncompleteRequestBodyIsNotSignedAsACompleteHash's fake to close the body (models a conformant RoundTripper); it still correctly records incomplete.

Full internal/httpx suite passes under -race -count=3.

[sigilix]

---

_{Posted · 3193b17 · 0 findings — View review
Sigilix · 0 of 50 reviews used in past 5h}

Sigilix is reviewing this pull request.

A structured overview will replace this note when retrieval and specialist review complete.

== star harbor ==
       .           *              .              *
                 .        __..----..__       .
         *             .-'   .  .     '-.
                    .-'   *       .       '-.
      .            /   .      .------.       \          .
                  ;          /  dock  \       ;
           .      |     *   /__________\  .   |    *
                  |        /|  []  [] |\      |
      *           ;       /_|__________|_\     ;
                   \        .  .  .  .        /
         .          '-.  every ship returns .-'      .
                       '-.  with a signal .-'
              *           '--..____..--'        *
       .                .              .              .

every small ship returns with light
some carry warnings, some carry peace

[qualitymaxapp]

QualityMax Review — canonical overview updated; inline findings are attached to this review.

[qualitymaxapp]

QualityMax Review

Verdict: COMMENT · Confidence: evidence-backed scan

Files eligible: 2 · Files reviewed: 2 · Files with findings: 0 · Findings: 0 · Inline cards: 0

Priority findings

priority	location	finding
—	—	No blocking findings

Review gates

gate	status
AI diff review	completed · eligible 2, reviewed 2 · LLM · served gemini-3.1-flash-lite
SAST	completed · eligible 2, reviewed 2 · hybrid · served gemini-3.1-pro-preview
Overall review evidence	clean
Inline evidence	not needed

Important files

file	risk	note	next step
—	—	No findings	—

Change diagram — Flow

flowchart TD
    A[RoundTrip Start] --> B[Wrap Body in hashingBody]
    B --> C[t.base.RoundTrip]
    C --> D{Wait for Body Close?}
    D -- Success --> E[Wait on hb.closed or Context]
    E --> F[Snapshot Body Hash]
    D -- Error --> F

Loading

Review lifecycle

Use the inline cards to inspect evidence and suggested remediation. Re-run the QualityMax review after pushing a fix; unchanged cards are identified by their stable finding marker. Dismiss with a reason through the existing QualityMax/GitHub review feedback flow. 0 prior card(s) are stale/resolved on this head. @qmax Q&A is tracked separately.

Proof legend: VERIFIED independently judged patch · REPRODUCED verified finding · GROUNDED deterministic evidence · MODEL-ONLY model judgment.

QualityMax project results are available in the configured project.

_{Receipt · commit 3193b17b19432f74f0b9435b1e5fe440d0de59a7 · run 2026-08-07T19:30:25+00:00 · model served gemini-3.1-pro-preview, gemini-3.1-flash-lite · model requested gemini-3.1-pro-preview, gemini-3.1-flash-lite · model review substantive — 958 model output tokens · model source repository ai_review_preferences.preferred_model · re-review 1 · proof counts {}}

[qualitymaxapp]

⚠️ QualityMax Pipeline

Gate	Result
🔍 AI diff review	✅ Clean · gemini-3.1-flash-lite · completed · 2 eligible / 2 reviewed · gemini-3.1-flash-lite
🔍 SAST	completed · 2 eligible / 2 reviewed · gemini-3.1-pro-preview
🔍 Canonical PR review delivery	completed · 0 eligible / 0 reviewed · exact-head review #4885982229 and overview #5221223149 confirmed
🧪 Repo Tests	✅ 581/581 passed (go)
🤖 AI Tests	⚠️ 51/56 passed

_{Powered by QualityMax — AI-Powered Test Automation}