* s3: answer GET and HEAD of a delete marker as S3 does
A delete marker as the current version now returns 404 NoSuchKey with
x-amz-delete-marker: true and the marker's x-amz-version-id. Asking for the
marker by versionId returns 405 MethodNotAllowed with the same headers and
Last-Modified, instead of 404 NoSuchKey.
* s3: check the tag-conditioned read grant before answering a delete marker
The marker branch returned before the entry-based policy recheck the rest
of the read path performs, so an s3:ExistingObjectTag-conditioned Deny did
not apply to the delete-marker response and its version headers.
* s3: send Allow: DELETE with the delete-marker 405
RFC 9110 15.5.6 requires a 405 answer to list the methods the resource
supports; S3 sends allow: DELETE for a delete marker named by versionId.
* s3: keep delete-marker headers on conditional-read misses
If-Match or If-Unmodified-Since against a current delete marker short-
circuited to a bare NoSuchKey. Carry the resolved marker through the
conditional result so the 404 keeps x-amz-delete-marker and
x-amz-version-id, matching the unconditional read.
* s3: exercise delete-marker responses through GET and HEAD handlers
* s3: read marker version id from the entry before the caller's guess
A delete marker written outside the normal PUT path can miss the
version-id attribute while the v_<id> file name still names it; the
new x-amz-version-id header would then report "null". Reuse
versionIdFromEntry so both the handler and conditional-miss paths
emit the real id.
* s3: answer 405 for versionId=null on a suspended-versioning marker
The null marker lives in .versions while getSpecificObjectVersion only
checks the plain path, so GET/HEAD ?versionId=null answered
NoSuchVersion. On that miss, look up the null marker and answer it
like any other marker named by versionId.
* s3: propagate null-marker lookup failures instead of answering 404
A transient filer error reading .versions/v_null was swallowed as
"no marker", so GET/HEAD answered NoSuchVersion for a live read
failure. NotFound and absent entries still mean no marker; anything
else is InternalError now.
---------
Co-authored-by: Chris Lu <chris.lu@gmail.com>
Co-authored-by: chrislusf <chrislusf@users.noreply.github.com>
see https://blog.aqwari.net/xml-schema-go/
1. go get aqwari.net/xml/cmd/xsdgen
2. Add EncodingType element for ListBucketResult in AmazonS3.xsd
3. xsdgen -o s3api_xsd_generated.go -pkg s3api AmazonS3.xsd
4. Remove empty Grantee struct in s3api_xsd_generated.go
5. Remove xmlns: sed s'/http:\/\/s3.amazonaws.com\/doc\/2006-03-01\/\ //' s3api_xsd_generated.go
