Merge pull request #12769 from calavera/git_build_fragment

Use git url fragment to specify build reference and dir context.

integration-cli/docker_cli_build_test.go

@@ -4118,6 +4118,35 @@ func (s *DockerSuite) TestBuildFromGIT(c *check.C) {
 	}
 }
 
+func (s *DockerSuite) TestBuildFromGITWithContext(c *check.C) {
+	name := "testbuildfromgit"
+	defer deleteImages(name)
+	git, err := fakeGIT("repo", map[string]string{
+		"docker/Dockerfile": `FROM busybox
+					ADD first /first
+					RUN [ -f /first ]
+					MAINTAINER docker`,
+		"docker/first": "test git data",
+	}, true)
+	if err != nil {
+		c.Fatal(err)
+	}
+	defer git.Close()
+
+	u := fmt.Sprintf("%s#master:docker", git.RepoURL)
+	_, err = buildImageFromPath(name, u, true)
+	if err != nil {
+		c.Fatal(err)
+	}
+	res, err := inspectField(name, "Author")
+	if err != nil {
+		c.Fatal(err)
+	}
+	if res != "docker" {
+		c.Fatalf("Maintainer should be docker, got %s", res)
+	}
+}
+
 func (s *DockerSuite) TestBuildCleanupCmdOnEntrypoint(c *check.C) {
 	name := "testbuildcmdcleanuponentrypoint"
 	if _, err := buildImage(name,