ERP5Form/hal_json_style: fix creation of ERP5 Form with newContent

This is not used directly when creating forms at the moment, but it's
useful for introspection to be able to create an instance of any portal
type with newContent()

bt5/erp5_hal_json_style/TestTemplateItem/portal_components/test.erp5.testHalJsonStyle.py

@@ -1203,3 +1203,13 @@ return msg"
     )
     result_dict = json.loads(result)
     self.assertEqual(result_dict['title'], 'Foo_zhongwen')
+
+
+class TestERP5FormAsPortalType(ERP5TypeTestCase):
+  def test_newContent(self):
+    # use portal_trash as a container as it allow anything
+    form = self.portal.portal_trash.newContent(
+        portal_type='ERP5 Form',
+        temp_object=True
+    )
+    self.assertEqual('ERP5 Form', form.getPortalType())

product/ERP5Form/Form.py

@@ -633,7 +633,7 @@ class ERP5Form(Base, ZMIForm, ZopePageTemplate):
     objectItems = ZMIForm.objectItems
     objectValues = ZMIForm.objectValues
 
-    def __init__(self, id, title, unicode_mode=0, encoding='UTF-8',
+    def __init__(self, id, title=None, unicode_mode=0, encoding='UTF-8',
                  stored_encoding='UTF-8'):
         """Initialize form.
         id    -- id of form
@@ -643,7 +643,7 @@ class ERP5Form(Base, ZMIForm, ZopePageTemplate):
                                                encoding, stored_encoding,
                                                unicode_mode)
         self.id = id
-        self.title = title
+        self.title = title or id
         self.row_length = 4
         self.group_list = ["left", "right", "center", "bottom", "hidden"]
         groups = {}