field_names should not be modified

babi_multiprocess.diff

@@ -20,10 +20,17 @@ index a21e9e63e8..bd22d3b073 100644
  
      def add(self, cls, type='model'):
 diff --git a/tryton/trytond/trytond/model/modelsql.py b/tryton/trytond/trytond/model/modelsql.py
-index a21e9e63e8..a204c6df01 100644
+index a21e9e63e8..e767d2e9ae 100644
 --- a/tryton/trytond/trytond/model/modelsql.py
 +++ b/tryton/trytond/trytond/model/modelsql.py
-@@ -753,7 +753,14 @@ class ModelSQL(ModelStorage):
+@@ -747,13 +747,21 @@ class ModelSQL(ModelStorage):
+         extra_fields = set()
+         if 'write_date' not in fields_names:
+             extra_fields.add('write_date')
++        fields_names = fields_names[:]
+         for field_name in fields_names:
+             if field_name in {'_timestamp', '_write', '_delete'}:
+                 continue
              if '.' in field_name:
                  field_name, field_related = field_name.split('.', 1)
                  fields_related[field_name].add(field_related)
@@ -39,7 +46,7 @@ index a21e9e63e8..a204c6df01 100644
              if hasattr(field, 'datetime_field') and field.datetime_field:
                  extra_fields.add(field.datetime_field)
              if field.context:
-@@ -1209,8 +1216,14 @@ class ModelSQL(ModelStorage):
+@@ -1209,8 +1217,14 @@ class ModelSQL(ModelStorage):
                  foreign_table = Model.__table__()
                  foreign_red_sql = reduce_ids(
                      Column(foreign_table, field_name), sub_ids)