Beagle SCM

ABC-011: HTTP serializer emits zero headers, always

HTTPutf8Feed builds its header slice from the same pointer twice — {http->headers[0], *http->headers} where headers is u8cssp, and a[0] == *a in C — so the header loop is dead code and every serialized message loses all headers (no Host, no Content-Length). Verified empirically by the 2026-07-07 reviewer: a parsed 2-header request re-serialized as "GET / HTTP/1.1rnrn". No test covers the Feed direction.

Input

Context

• HTTP.c:76-77 — u8css hdrs = {http->headers[0], *http->headers}; yields {p, p}, $len == 0, loop never entered. Intended: {http->headers[0], http->headers[1]}.
• HTTP.lex:41 — ReasonPhrase = text requires ≥1 char; RFC 7230 allows an empty reason-phrase ("HTTP/1.1 200 rn", common from proxies) → HTTPBAD on legal responses.
• HTTP.c:93 HTTPfind(u8cs *value, u8cs key, ...) — immutable needle typed as consumable u8cs, should be u8csc (abc.mkd: consumption is signalled by type).
• HTTP.c:86 — hdrs[0] += 2; raw slice-pointer arithmetic; use the typed movers. HTTPutf8Drain (HTTP.c:39) is named Drain but never advances the caller's slice — naming/contract drift.

Goals

• Repro FIRST: parse→serialize round-trip test asserting headers survive; an empty-reason response parse.
• Fix the slice construction, relax the grammar (regen from HTTP.lex — mind the LEX template drift, ABC-017), tighten the signatures.

Constraints

• Grammar change means regenerating HTTP.rl.c — the current LEX.c template emits fbreak where the committed generated file has goto _out (ABC-017); regen must not silently change semantics.
• Review-gated abc/.

WIP

Design decisions

• Regen WITHOUT waiting on ABC-017: the fixed grammar's regen diff vs committed HTTP.c.rl is ONLY the known drift (16x fbreak vs goto out + 2 include paths) + the one HTTPtext? line, so that line was ported by hand keeping the committed goto out form; LEX template untouched (stays ABC-017's).
• HTTPutf8Drain kept, now honors the Drain contract (mirrors the lexer's consumption back via u8csMv on OK).

TODOs

• round-trip repro (HTTPtest4) + empty-reason repro (HTTPtest5), both red pre-fix
• fix hdrs slice (a_dup, HTTP.c:79); u8cssUsed mover (:89)
• empty ReasonPhrase in HTTP.lex:41 + hand-ported regen
• HTTPfind needle u8csc; HTTPutf8Drain advances caller slice

Blockers and bummers

• HTTPtest is WITH_INET-gated — invisible to the default 46-test run until ABC-017 lands the lane; verified with -DWITH_INET=ON.

Outcome

• Landed in work/ABC-011, NOT merged: ?3b156ca0 "ABC-011: HTTP serializer emits headers; empty reason ok". Suite 52/52 with WITH_INET=ON (baseline 46/46 + HTTPtest red once enabled); orchestrator re-verified suite + fixes.