Access denied to parent entity attribute for user without system-full-access role

[owlet1997]

based on forum's question

Environment

CUBA Platform version: 7.2.12
CUBA Studio plugin version: 15.3-202
IntelliJ version: IntelliJ IDEA 2020.3.1 (Community Edition)

Description of the bug

• Minimal reproducible example

1. Open attached project -> open data store settings and set right credentials -> create database
2. Run app -> login as admin
3. Create any students in student browser
4. Open tenant management -> create tenant name 'user' -> generate group -> create admin for this tenant
5. Set name 'user', password 'user', add role 'default-admin-tenant' -> Save
6. Create role 'newrole' with access to entity Student, screens Student browser and Student Reports, menu items Application, reports -> save -> add to user 'user' this role -> save
7. Logout and login as user -> open Student Reports screen

AR:

15:17:45.732 ERROR c.h.cuba.core.sys.ServiceInterceptor    - Exception in DataService.loadValues(..): com.haulmont.cuba.core.global.AccessDeniedException: ENTITY_ATTR testapp_Student.e.nation
15:17:45.737 ERROR com.haulmont.cuba.web.log.AppLog        - Exception in com.haulmont.cuba.web.widgets.CubaSideMenu: com.haulmont.cuba.core.global.AccessDeniedException: ENTITY_ATTR testapp_St

udent.e.nation

user has no access to attributes of entity NationEntity which is parent for Student
even admin has no opportunity to get access to parent entity because it's a mappedsuperclass

ER:
user should have access to parent entity attributes if access to child entity was permitted

[trx0eth7]

In our project, we use default permission for any role, so maybe it's useful to someone as a workaround.
You should set up the next to app.properties:

cuba.security.defaultPermissionValuesConfigEnabled = true
cuba.defaultPermissionValuesConfig = +/com/path/some-permission-values.xml

some-permission-values.xml:

<default-permission-values xmlns="http://schemas.haulmont.com/cuba/default-permission-values.xsd">
    <!-- Entities -->
    <permission target="prefix$MappedSuperClass:property" value="1" type="30"/>
</default-permission-values>`