@@ -9,6 +9,7 @@ import (

 	"github.com/docker/docker/daemon"

 	"github.com/docker/docker/engine"

+	"github.com/docker/docker/graph"

 	"github.com/docker/docker/pkg/archive"

 	"github.com/docker/docker/pkg/parsers"

 	"github.com/docker/docker/registry"

@@ -42,7 +43,18 @@ func (b *BuilderJob) CmdBuild(job *engine.Job) engine.Status {

 	)

 	job.GetenvJson("authConfig", authConfig)

 	job.GetenvJson("configFile", configFile)

+

 	repoName, tag = parsers.ParseRepositoryTag(repoName)

+	if repoName != "" {

+		if _, _, err := registry.ResolveRepositoryName(repoName); err != nil {

+			return job.Error(err)

+		}

+		if len(tag) > 0 {

+			if err := graph.ValidateTagName(tag); err != nil {

+				return job.Error(err)

+			}

+		}

+	}

 	if remoteURL == "" {

 		context = ioutil.NopCloser(job.Stdin)