lib/rbbt/tsv/change_id.rb in rbbt-util-5.5.27 vs lib/rbbt/tsv/change_id.rb in rbbt-util-5.5.28

@@ -30,10 +30,11 @@
   def self.swap_id(tsv, field, format, options = {})
     options = Misc.add_defaults options, :persist => false, :identifiers => tsv.identifiers
 
     identifiers, persist_input = Misc.process_options options, :identifiers, :persist
 
-    index = identifiers.index :target => format, :fields => [field], :persist => persist_input
+    fields = identifiers.all_fields.include?(field)? [field] : nil
+    index = identifiers.index :target => format, :fields => fields, :persist => persist_input
 
     orig_type = tsv.type 
     tsv = tsv.to_double if orig_type != :double
 
     pos = tsv.fields.index field