I am afraid I no longer have access to the code so I can't help you with providing the exact used scenario or a test.

As far as I could gather from the actual specifications of HLA requestAttributeOwnershipRelease can also be followed by negotiatedAttributeOwnershipDivestiture (according to the convoluted graph that is included)

Sorry I can't be of more help.

Different methods to transfer the ownership (from the book of Carl Tropper).

1 -> "Push" method: The federate which owns the attribute initiates the ownership exchange by informing the RTI of its willingness to give up the ownership.

2 -> "Pull" method: The federate which wish to take over the ownership of a given attribute sends an acquisition request to the RTI and initiates the process.

For the push, there is two variants (1-a) unconditional or (1-b) negociated (conditional).

(1-a) In the unconditional approach, the owner inform the RTI that it wish to give up the ownership without knowledge of any receivers. The federate can immediately release the ownership by calling the  unconditionalAttributeOwnershipDivestiture

For (1-b), the owner federate makes sure that there is an interested party among the other federates before releasing the ownership. This process starts per a call to negotiatedAttributeOwnershipDivestiture, then the RTI propagate the info to all eligible federate for this ownership by sending "requestOwnershipAssumption". THen if there is a federate interested per the ownership, it can reply with the call "attributeOwnershipAcquisitionIfAvailable".

Joris, can you share your test case illustrating this behavior for further testing of process 1-b)

I was testing the transferal of attribute ownership and noticed that for a case where a single attribute was being transferred the RTIG crashes.

In this case, a requestAttributeOwnershipRelease  is followed by a negotiatedAttributeOwnershipDivestiture for the attribute.
This all goes well until way into the governor where:

void NM_Attribute_Ownership_Base::setAttributes(const AttributeHandle& newAttributes, uint32_t rank)

from NM_Classes.hh is invoked:
"void setAttributes(const AttributeHandle& newAttributes, uint32_t rank) {attributes[rank]=newAttributes;}"

However, the vector attributes is not correctly sized to accomodate the new attribute. This leads to an exception.

Workaround is using attributeOwnershipDivestitureIfWanted or unconditionalAttributeOwnershipDivestiture