can not delete repeatable nested element in WCM

• Type: Regression Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.0 DXP FP13, 7.0.X EE, Master
• Fix Version/s: 7.0.0 DXP FP18, 7.0.3 CE GA4, 7.0.0 DXP SP4, 7.0.X EE, 7.1.X, Master
• Component/s: Dynamic Data Mapping
• Labels:
  • NAT
  • QA-V
  • ee-ts
  • fw_test_needed
  • liferay-digital-enterprise-70-sp4
  • liferay-fixpack-de-18-7010
• Branch Version/s:
  7.0.x
• Backported to Branch:
  Committed
• Story Points: 1
• Fix Priority: 4
• Git Pull Request: https://github.com/liferay/com-liferay-dynamic-data-mapping/pull/203

Repeated Nested repeatable field can not be deleted when editing a web content

Steps to reproduce

Create a nested WCM structure (root: repeatable separator, child: text)
Create a template
Create a content with two element (click on +) and try to delete one with the "-" button

Experienced result
Field can not be deleted
Javascript error in Chrome console

Hints
aui-form-validation.js resetField method should return immediately if its parmeter is null
OR
ddm-fomr.js remove method should not call instance._removeFieldValidation(instance); for instances which is not validatable. In our case the instance is the remove-button.