Three branches: gRPC error from GetFilerConfiguration must propagate
(else Execute would proceed to dial S3 with an empty buckets path
and never dispatch); a non-empty DirBuckets is honored verbatim so
operators with a non-default layout aren't force-routed to /buckets;
an empty DirBuckets falls back to the documented "/buckets" default
rather than returning empty (which would route to root). stubFilerConfigClient
embeds filer_pb.SeaweedFilerClient so methods other than the one
under test panic if called — keeps the surface narrow.
Chris LuandGitHub
9d20e71883