If another module also triggers a save (like an entity_update hook), the new group content entity can be "re-saved" causing an exception.
Drupal\Core\Entity\EntityStorageException: Update existing 'group_content' entity while changing the ID is not supported. in Drupal\Core\Entity\Sql\SqlContentEntityStorage->save() (line 811 of core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php). Drupal\Core\Entity\EntityStorageBase->save(Object) (Line: 802) Drupal\Core\Entity\Sql\SqlContentEntityStorage->save(Object) (Line: 339) Drupal\Core\Entity\EntityBase->save() (Line: 68) Drupal\entitygroupfield\Field\EntityGroupFieldItemList->postSave(1) ....
Once we save the group_content_entity, unset the property which executes the save.
Needs work
1.0
Code
The change is currently missing an automated test that fails when run with the original code, and succeeds when the bug has been fixed.
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It's likely this issue predates Contrib.social: some issue and comment data are missing.
Thanks for reporting this, and providing a fix! There's code here to review, so changing status. That should also trigger a test run, so we can see if the patch still applies, existing tests pass, etc.
Cool, nice to see the patch still applies and existing tests pass. However, I'm trying to keep good test coverage in here, so I don't want to commit any changes without tests.