[CAUSEWAY-627] Lazily loaded object cannot be deleted, throws an NPE

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: core-1.3.0
• Fix Version/s: core-1.4.0
• Component/s: Core
• Assignee: Daniel Keir Haywood
• Reporter: Daniel Keir Haywood
• Created: 06/Dec/13 15:53
• Updated: 11/Mar/14 07:39
• Resolved: 06/Dec/13 16:22

Description

In Estatio, the LeaseTerm entity forms a chain, each pointing to the previous and next. When a Lease is terminated, the algorithm is to spin through all the LeaseTerms and those in the future that are no longer needed. This is done recursively:

LT1 -> LT2 -> LT3 -> LT4

So, for example LT3 and LT4 would be deleted.

The issue we've found is that calling container.remove() on LT4 fails with an NPE in core (PersistenceSession#destroyObject. This is because the adapter passed in is null.

~~~
The root cause seems to be that LT4 is lazily loaded from LT3. JDO hasn't yet had occasion to load LT4, which means, in turn, that the pojoAdapter/pojo are not in Isis maps.

In the call to PersistenceSession#destroyObject, the code is using AdapterManager#getAdapterFor(pojo), which will return null if the object is not yet loaded in the maps.

The fix is a one-liner... use AdapterManager#adapterFor(pojo), which will map the pojo to a pojoAdapter if required.