Relative Location redirects crash httpRequest with TypeError: Invalid URL

Finding: In an external report against puppeteer/puppeteer issue 15511, httpRequest in @puppeteer/browsers (packages/browsers/src/httpUtil.ts, main at time of report, no release pinned) reportedly throws TypeError: Invalid URL when a 3xx response carries a relative Location header such as /file.bin or file.bin. Absolute Location values are reported to still work (https://github.com/puppeteer/puppeteer/issues/15511). Reported symptom and environment: The reporter says the redirect branch passes the header straight to new URL(), which needs an absolute URL. The exception is thrown inside the response callback, is uncaught, and the promise from downloadFile or getText reportedly never rejects. The reporter supplies a repro with a local node:http server that answers /start with a 302 to /file.bin and then calls downloadFile; the error trace shows ERR_INVALID_URL with input /file.bin. The reporter notes that custom --base-url mirrors and reverse proxies often send path-only Location headers, so such setups may be affected. That is the reporter's assessment, not a confirmed scope. Expected behavior per the report: Relative Location values should be resolved against the request URL, citing WHATWG and RFC 9110, so /file.bin from http://127.0.0.1:PORT/start fetches http://127.0.0.1:PORT/file.bin. Maintainer status: A collaborator comment on 2026-10-01 only asked another person to triage and apply a Confirmed or Needs-feedback label. It does not confirm the cause. A later comment from an unaffiliated user is generic, suggesting redirect URLs be resolved against the base URL and validated, and adds no verification. The issue was open at the last supplied update on 2026-10-05. Fix status: Unknown. The supplied sources contain no fix commit, pull request or released version, so no fix or workaround can be claimed. Limitations: This record rests on one external report and is not a KFA reproduction. The affected release is not pinned, and middle comments may be missing from the supplied timeline. Treat the diagnosis as the reporter's hypothesis until maintainers confirm it. If you hit this, the report's only actionable diagnostic is to check whether the server or mirror returns a path-only Location header on a redirect.