A file entry in a zip whose name refers to a directory, such as ".",
"/", "" or "sub/.", was only skipped when it named the root of an
archive which was itself the root of the remote. When the archive was
found by listing its parent directory the entry appeared as a file
with the same name as the archive alongside the directory for it, and
copying the archive tried to write both. When the entry named a
subdirectory it appeared as a file alongside that directory, and with
that subdirectory mounted as the archive root the entry was taken to
be the single file the root points at, hiding every real entry.
Skip any file entry whose last path component is "", "." or "..",
checked on the raw name before it is cleaned or joined on the prefix.
The zip archiver handed out its cached directory tree directly. Any
caller which filters a listing in place (as the core listing code
does) altered the cache, so later listings of the same directory could
be corrupted.
Return a copy of the cached listing instead.
A zip containing a file entry whose name refers to the archive's own
root (".", "/" or "") was presented as a single file called "." and
all its other entries disappeared. A file at the root can only be the
archive member the backend was pointed at, so with no root such an
entry is skipped like any other unsafe name.
When a zip archive was mounted at a subdirectory root, readZip used a bare
strings.HasPrefix to decide which entries fell inside the root. This
matched on a raw string prefix rather than a path boundary, so mounting
root "foo" also exposed sibling entries such as "foobar/..." with their
names left uncorrected.
Require a path boundary when filtering by root.
The zip backend mounts a zip file as a browsable Fs. Go's archive/zip
does not sanitize entry names, and readZip applied path.Clean but did
not reject a cleaned name that still pointed outside the archive. A
crafted zip could make rclone copy/sync attempt writes outside the
intended destination.
Sanitize entry names with sanitize.Path - the same check used by
rclone archive extract - skipping any entry with a ".." path
component, whether separated by "/" or "\". A backslash is otherwise
kept as an ordinary character in the name, as archive extract does. It
is up to the destination backend to make names safe for its storage.
Skipped entries are logged as a single count per archive so a crafted
archive with many escaping entries cannot flood the log.
Add a ctx parameter to vfs.New() so callers can pass in context
carrying ConfigInfo and FilterInfo. The context is stripped of
cancellation but config and filter values are preserved into a fresh
background context.
Nick Craig-Wood