Merge pull request #297 from floaust/master

fix nil pointer in errors.Hide()

Author: daemonfire300

maintenance/errors/context.go

@@ -13,8 +13,12 @@ import (
 // the optional exposedErr is provided, it is attached as prefix
 // to the returned error. If the given err is not any of the above
 // ones, the given exposedErr (if present) is wrapped as prefix
-// to the returned error.
+// to the returned error, if there is an err that is not nil.
 func Hide(ctx context.Context, err, exposedErr error) error {
+	if err == nil {
+		return nil
+	}
+	
 	ret := errors.New(err.Error())
 	if exposedErr != nil {
 		ret = fmt.Errorf("%w: %s", exposedErr, err)