https://mvega.dev/tags/net/http/Recent content in Net/Http on Moises VegaHugoen-usMoises VegaThu, 20 Aug 2026 00:00:00 +0000https://mvega.dev/posts/go-http-body-close-eof/Thu, 20 Aug 2026 00:00:00 +0000https://mvega.dev/posts/go-http-body-close-eof/<p>While testing an internal HTTP service against Go 1.27, a handler that had worked for years started reporting errors from an unlikely place: <code>r.Body.Close()</code>.</p> <p>The handler does what any length-aware decoder does — it reads exactly the payload it expects and stops, without reading far enough to observe <code>io.EOF</code>. Then it closes the body. On Go 1.26 that <code>Close</code> returned <code>nil</code>. On 1.27 it returns <code>io.EOF</code>.</p> <h2 id="pinning-it-down">Pinning it down</h2> <p>Timer-driven HTTP repros are flaky, so I drove <code>net/http</code> over a <code>net.Pipe</code> with a one-shot listener: fully deterministic, no real sockets, no timeouts. The whole thing fits in a <a href="https://go.dev/play/p/P6gM5GS84Vq">playground link</a>. A handler reads 2 of 4 body bytes, closes, and reports the error:</p>