The test was passing previously because the preamble was already buffered. After
the change to return Scanner.Err() the final read error on the buffer was no
longer being ignored.
Signed-off-by: Daniel Nephin <dnephin@docker.com>
This enables docker cp and ADD/COPY docker build support for LCOW.
Originally, the graphdriver.Get() interface returned a local path
to the container root filesystem. This does not work for LCOW, so
the Get() method now returns an interface that LCOW implements to
support copying to and from the container.
Signed-off-by: Akash Gupta <akagup@microsoft.com>
