Read-only Text Fields in the Edit Screen will be cleared when the issue is edited

Summary

Editing custom fields using the Edit Screen will delete the data for any Text Fields (read only) custom fields which are included in the 'Edit Issue' screen.

Steps to Reproduce

1. Create a text custom field (e.g. rw-text-field).
2. Create a Text Field (read only)) custom field.
3. Add both fields to the 'Create Issue' and 'Edit Issue' screen for a project.
4. Create a new issue programmatically (e.g. using the REST API) setting both fields during creation.
5. After the issue is created, edit the rw-text-field field using the 'Edit Screen'.

Expected Results

Only the Text Field is updated with the latest changes.

Actual Results

• All existing Text Field (read only) fields included in the 'Edit Screen' are cleared.
• Their data is purged from the DB.
• The change log does not document this change so it might even go unnoticed (e.g. if the field is in a tab).

Workaround

• Associate read-only text fields only to the 'Create Issue' screen and remove their association from the 'Edit Issue' screens.
  • This change will prevent the field from being updated via the REST API, except when the issue is created.
• Update the Custom Field type to Writeable Text Field following the steps in Changing Custom Field Types in JIRA

Notes

• Using the in-line editing won't cause this problem, but this is not be possible for fields without a value.