* webdav: delete a folder with its contents
* webdav: guard the recursive delete against stale and confined paths
- propagate stat lookup errors instead of returning an error-bearing
FileInfo: OpenFile and DELETE would otherwise take the recursive
removeAll on a path whose type was never confirmed, wiping a
directory on a transient filer error
- refuse wrappedFs.Rename from or to the served root, matching the
RemoveAll guard and webdav.Dir
- normalize trailing slashes in removeAll so the delete names the
entry itself, and refuse the root for every caller
* webdav: keep file-only deletes shallow and refuse ancestor destinations
- removeAll used by OpenFile and failed-upload cleanup now deletes
non-recursively, so a folder swapped in after the stat check is not
emptied by a pending file delete
- MOVE and COPY whose destination contains the source are refused
before the handler removes the destination, which would otherwise
take the source down with it
* webdav: also refuse a destination inside the source
a MOVE or COPY into its own subtree recurses into the destination it
just created; refuse it with the same guard instead of burning the
recursion budget for a 500
* webdav: allow a shallow copy into the source subtree
a COPY with Depth: 0 creates only the destination collection and never
reads children, so it is safe inside the source; only deep copies and
moves are refused there
* webdav: refuse a copy/move whose source is unreadable
* webdav: cover the missing-source refusal in the guard test
* webdav: 500 on a source lookup failure, 404 only when absent
---------
Co-authored-by: Chris Lu <chris.lu@gmail.com>
Co-authored-by: Chris Lu <chrislusf@users.noreply.github.com>
