This refines the check for determining whether exec will succeed to work
when an error occurs. This check previously relied on the `Ref` being
populated in the result context but this would only happen if we were
paused from a breakpoint or by stepping. An error would not fill in this
field.
The check is now refined to use the new gateway filesystem exec API so
we can create the container and then check even if we don't have a
returned gateway reference. The logic to determine which mount to check
has also been moved.
Signed-off-by: Jonathan A. Sternberg <jonathan.sternberg@docker.com>
Jonathan A. Sternberg
b33ef2c9d4