json: avoid duplicate response after write failures - #1100
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JSON response writes may fail only after the successful status has already been committed. Treat the controlled response types as serializable and avoid attempting a second error response, which cannot change the status and produces a superfluous WriteHeader warning. Amp-Thread-ID: https://ampcode.com/threads/T-019fa815-b759-72ab-9771-e4008fbbf378
keegancsmith
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keegancsmith
marked this pull request as ready for review
July 28, 2026 10:48
burmudar
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Jul 28, 2026
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The JSON search and list handlers currently treat every encoder error as though an HTTP 500 can still be sent. In practice, the response types are known to serialize successfully, while transport failures occur after
ResponseWriter.Writehas already committed HTTP 200. CallingjsonErrorat that point cannot change the response and causes thehttp: superfluous response.WriteHeader callwarning reported in #1099.This routes both successful response types through a small helper that encodes directly to the response writer and intentionally ignores encoder errors. Direct encoding retains the encoder’s pooled buffer behavior and avoids the response-sized copy that pre-marshalling would require. The existing
application/jsonheader is set rather than appended.Fixes #1099