nx_url_resolve.nx

nx_url_resolve.nx -- RFC 3986 §5.2 relative-URL resolution. Given a base URL (assumed absolute: scheme://authority/path...) and a reference URL (absolute, scheme-relative, path-absolute, path-relative, or fragment-only), compute the resolved absolute URL and write it to caller-supplied output buffer. This is the substrate primitive Arc B2 needs to turn the raw <img src="..."> values harvested from a Google response into fetchable absolute URLs. Covered cases (in roughly the order RFC 3986 §5.2 specifies): - rel is absolute (has its own scheme): output = rel verbatim - rel starts with "//": output = base.scheme + ":" + rel - rel starts with "/": output = base.scheme + "://" + base.authority + rel - rel is empty or "#frag": output = base with optional new fragment - rel is path-relative: output = base.scheme + "://" + base.authority + merged-and-dot-resolved path + rel.query/frag Out of scope (deferred to a real-Google-response-driven slice): - userinfo (user:pass@host) - IPv6 [..] hosts - punycode/IDN - normalize_case of host (spec says lower) - percent-decode/re-encode round-trip nx_safety_envelope: intended_use: "Relative-URL resolution for HTML href/src in the bits-up browser substrate." sil_target: SIL1 evidence: [RFC3986_section_5_2_canonical_basis, bounded_output_buffer, substrate_honest_truncation_signal] hazard_register: [bug-tape-path-traversal-via-dot-dot, bug-tape-host-substitution-via-malformed-base] residual_risk: "Caller is responsible for sandboxing fetch targets; resolver does not enforce origin policy." verdict: NOT_YET_EVALUATED