1. As daemon.ContainerStop() documentation says,
> If a negative number of seconds is given, ContainerStop
> will wait for a graceful termination.
but since commit cfdf84d5d0 (PR #32237) this is no longer the case.
This happens because `context.WithTimeout(ctx, timeout)` is implemented
as `WithDeadline(ctx, time.Now().Add(timeout))`, resulting in a deadline
which is in the past.
To fix, don't use WithDeadline() if the timeout is negative.
2. Add a test case to validate the correct behavior and
as a means to prevent a similar regression in the future.
3. Fix/improve daemon.ContainerStop() and client.ContainerStop()
description for clarity and completeness.
4. Fix/improve DefaultStopTimeout description.
Fixes: cfdf84d5d0 ("Update Container Wait")
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Since Go 1.7, context is a standard package. Since Go 1.9, everything
that is provided by "x/net/context" is a couple of type aliases to
types in "context".
Many vendored packages still use x/net/context, so vendor entry remains
for now.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
