Adds a read-only example that exercises the connector against a real
Nextcloud: Login Flow v2, PROPFIND listing, the Depth:0 ETag pruning
probe, a 256KB range GET, and a server preview request. No PUT, MOVE or
DELETE, so it cannot alter a live library.
Running it against nextcloud.tourolle.paris (34.0.2) surfaced a real API
flaw rather than an example bug. The crypto provider was installed in
NextcloudBackend::new, but authentication necessarily runs *before* a
backend exists — so any caller following the documented flow panicked on
the first client build. Every entry point now goes through
`http_client()`, which installs the provider first, and auth gains
`begin_default()` for callers with no client yet. A test builds a client
without a backend to keep the regression out.
Also populates RawImage::crop from rawler's crop_area/active_area and
re-phases the CFA pattern when the crop origin is odd — cropping to the
active area without that swaps red and blue.
Login Flow v2 confirmed working against the live server: the flow URL is
issued and the poll endpoint responds. The remaining checks need a
browser approval, so they run interactively.
88 tests passing.
Investigated using the Nextcloud desktop client's Virtual Files as a
cache instead of talking to the server directly. Measured on this
machine (client 4.0.7): the configured folder holds 121,785 placeholders
against 10,267 materialised files, including 7,037 CR2 and 9,411 DNG.
Three findings, each independently disqualifying:
- Linux VFS is *suffix* mode. A dehydrated IMG.CR2 exists only as
IMG.CR2.nextcloud holding one byte; the real name is absent.
- Reading a placeholder does not hydrate it. dd of the first 256KB
returned 1 byte, the stub was unchanged, and the real name never
appeared. There is no FUSE layer — the stub is an inert marker.
- Even with hydration the granularity is wrong: VFS has two states,
1 byte or all bytes, and the preview tier needs a ~256KB prefix of
a 27MB file. That is ~100x what FR-NC-3 requires.
Recorded as ARCH §9.0. Coexistence is still supported: dr-types now
recognises *.nextcloud stubs, and the viewer lists them as "not
downloaded" rather than as corrupt files or not at all.
So the connector talks to the server directly, as D7 specified.
Implemented: Login Flow v2, PROPFIND with oc:fileid and nc:has-preview,
ETag pruning via a Depth:0 probe, range GET with local slicing when the
server ignores the header, conditional PUT, and /core/preview with
forceIcon=false. delta() returns Unsupported and says why.
Chunked upload v2 is not implemented yet — put() rejects bodies over
5MB explicitly rather than silently truncating.
Two bugs found by testing: my hand-computed epoch in a date test was a
day out (the parser was right), and quick-xml reaches EOF on truncated
input without erroring, so unbalanced elements needed an explicit check
— a half-parsed multistatus must not look like an empty directory.
83 tests passing.