Support for "directory" objects (#10499)

cmd/object-api-errors.go

@@ -22,12 +22,18 @@ import (
 	"fmt"
 	"io"
 	"path"
+	"strings"
 )
 
 // Converts underlying storage error. Convenience function written to
 // handle all cases where we have known types of errors returned by
 // underlying storage layer.
 func toObjectErr(err error, params ...string) error {
+	if len(params) > 1 {
+		if HasSuffix(params[1], globalDirSuffix) {
+			params[1] = strings.TrimSuffix(params[1], globalDirSuffix) + slashSeparator
+		}
+	}
 	switch err {
 	case errVolumeNotFound:
 		if len(params) >= 1 {