The prefix was only trimmed. Without a leading slash ServeMux read its first
segment as a host pattern, so every upload silently answered 404, and a CDN
URL panicked in ServeMux and surfaced as a misleading route conflict. With
storage.uploads.serve on, BuildRouter now refuses a prefix that is not an
absolute URL path (scheme, host, query, fragment, whitespace, wildcard
braces, empty, . or .. segments, or a bare /) with an error naming the key.
The route answered with the blob's stored Content-Type, which attach.Store
sniffs from the bytes, so a public text upload starting with <html> was
served as text/html on the application origin; nosniff does not help when
the declared type is already HTML. Every response now carries a sandboxing
Content-Security-Policy, and a successful response whose type is not a
raster image (JPEG, PNG, GIF, WebP, AVIF) gets Content-Disposition:
attachment, on GET and HEAD. Covers stay inline.
- TestUploadsMount: key off registers nothing; on, a public blob is served
with its content type and nosniff, HEAD has no body, private, missing,
partition and encoded traversal paths 404, an unpublished bucket or
database 404s, a custom prefix is honoured
- mountUploads refuses a plugin route at or under the prefix, so
BuildRouter fails instead of only an identical pattern failing at
Assemble (README and storage docs updated)
- TestAccessLog: pattern and status for 200, handler 404 and recovered
panic, path only for unmatched requests, locale-prefixed requests keep
the pattern, integer duration_ms, no query, header or Authorization
value, ResponseController flush still works
