completion v2: some small follow-ups

- Prevent completion on "create" subcommands to prevent them
  from completing with local filenames
- Add completion for "docker image save"
- Add completion for "docker image tag"
- Disable completion for "docker login"
- Exclude "paused" containers for "docker container attach" and
  "docker container exec"

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/image/save.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/docker/cli/cli"
 	"github.com/docker/cli/cli/command"
+	"github.com/docker/cli/cli/command/completion"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 )
@@ -27,6 +28,7 @@ func NewSaveCommand(dockerCli command.Cli) *cobra.Command {
 			opts.images = args
 			return RunSave(dockerCli, opts)
 		},
+		ValidArgsFunction: completion.ImageNames(dockerCli),
 	}
 
 	flags := cmd.Flags()