Update image pull tests

Update and migrate existing tests to the `DockerHubPullSuite`. Most
tests were preserved, but refactored and made more exhaustive. One test
was deliberately removed (`TestPullVerified`) as it is unreliable and
that the feature was obsoleted by content trust.

Move all trust related tests to `docker_cli_pull_trusted_test.go`.

Move tests depending on a local registry to `docker_cli_pull_local_test.go`.

Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>

integration-cli/docker_cli_pull_local_test.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/go-check/check"
+)
+
+// TestPullImageWithAliases pulls a specific image tag and verifies that any aliases (i.e., other
+// tags for the same image) are not also pulled down.
+//
+// Ref: docker/docker#8141
+func (s *DockerRegistrySuite) TestPullImageWithAliases(c *check.C) {
+	repoName := fmt.Sprintf("%v/dockercli/busybox", privateRegistryURL)
+
+	repos := []string{}
+	for _, tag := range []string{"recent", "fresh"} {
+		repos = append(repos, fmt.Sprintf("%v:%v", repoName, tag))
+	}
+
+	// Tag and push the same image multiple times.
+	for _, repo := range repos {
+		dockerCmd(c, "tag", "busybox", repo)
+		dockerCmd(c, "push", repo)
+	}
+
+	// Clear local images store.
+	args := append([]string{"rmi"}, repos...)
+	dockerCmd(c, args...)
+
+	// Pull a single tag and verify it doesn't bring down all aliases.
+	dockerCmd(c, "pull", repos[0])
+	dockerCmd(c, "inspect", repos[0])
+	for _, repo := range repos[1:] {
+		if _, _, err := dockerCmdWithError("inspect", repo); err == nil {
+			c.Fatalf("Image %v shouldn't have been pulled down", repo)
+		}
+	}
+}