finally fix master

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

vendor/github.com/docker/distribution/manifests.go

@@ -2,7 +2,7 @@ package distribution
 
 import (
 	"fmt"
-	"mime"
+	"strings"
 
 	"github.com/docker/distribution/context"
 	"github.com/docker/distribution/digest"
@@ -84,23 +84,19 @@ var mappings = make(map[string]UnmarshalFunc, 0)
 // UnmarshalManifest looks up manifest unmarshall functions based on
 // MediaType
 func UnmarshalManifest(ctHeader string, p []byte) (Manifest, Descriptor, error) {
-	// Need to look up by the actual media type, not the raw contents of
+	// Need to look up by the actual content type, not the raw contents of
 	// the header. Strip semicolons and anything following them.
 	var mediatype string
-	if ctHeader != "" {
-		var err error
-		mediatype, _, err = mime.ParseMediaType(ctHeader)
-		if err != nil {
-			return nil, Descriptor{}, err
-		}
+	semicolonIndex := strings.Index(ctHeader, ";")
+	if semicolonIndex != -1 {
+		mediatype = ctHeader[:semicolonIndex]
+	} else {
+		mediatype = ctHeader
 	}
 
 	unmarshalFunc, ok := mappings[mediatype]
 	if !ok {
-		unmarshalFunc, ok = mappings[""]
-		if !ok {
-			return nil, Descriptor{}, fmt.Errorf("unsupported manifest mediatype and no default available: %s", mediatype)
-		}
+		return nil, Descriptor{}, fmt.Errorf("unsupported manifest mediatype: %s", mediatype)
 	}
 
 	return unmarshalFunc(p)