Error out if no validate layers found during unpacking

coolljt0725 · coolljt0725 · commit 290cb54341fd · 2016-09-06T11:32:23.000+08:00
Signed-off-by: Lei Jitang &lt;leijitang@huawei.com&gt;
diff --git a/image/manifest.go b/image/manifest.go
@@ -117,7 +117,7 @@ func (m *manifest) unpack(w walker, dest string) error {
 			return err
 		}
 	}
-	return nil
+	return fmt.Errorf("no validate layers found")
 }
 
 func unpackLayer(dest string, r io.Reader) error {

Original file line number	Diff line number	Diff line change
`@@ -117,7 +117,7 @@ func (m *manifest) unpack(w walker, dest string) error {`
`117`	`117`	`return err`
`118`	`118`	`}`
`119`	`119`	`}`
`120`		`- return nil`
	`120`	`+ return fmt.Errorf("no validate layers found")`
`121`	`121`	`}`
`122`	`122`
`123`	`123`	`func unpackLayer(dest string, r io.Reader) error {`