Act as if there is an author in the feed when only checking the entry

entry.go

@@ -34,14 +34,16 @@ type Entry struct {
 // the atom:entry contains an atom:source element that contains an atom:author
 // element or, in an Atom Feed Document, the atom:feed element contains an
 // atom:author element itself.
-func (e *Entry) checkAuthors() error {
+func (e *Entry) checkAuthors(authorInFeed bool) error {
 	if e.Authors == nil {
+		if !authorInFeed {
 			if e.Source == nil {
 				return errors.New("no authors set in entry")
 			}
 			if e.Source.Authors == nil {
 				return errors.New("no authors set in entry")
 			}
+		}
 	} else {
 		for i, a := range e.Authors {
 			if err := a.Check(); err != nil {
@@ -138,7 +140,7 @@ func (e *Entry) Check() error {
 		}
 	}
 
-	if err := e.checkAuthors(); err != nil {
+	if err := e.checkAuthors(true); err != nil {
 		return fmt.Errorf("entry %v: %v", e.ID.URI, err)
 	}
 

feed.go

@@ -128,7 +128,7 @@ func (f *Feed) Check() error {
 	// least one atom:author element.
 	if f.Authors == nil {
 		for _, e := range f.Entries {
-			if err := e.checkAuthors(); err != nil {
+			if err := e.checkAuthors(false); err != nil {
 				return fmt.Errorf("no authors set in feed %v: %v", f.ID.URI, err)
 			}
 		}