MemoryStore fails to read data involving persisted nested triples

[pulquero]

Current Behavior

Trying to create a MemoryStore from a datafile containing a nested Triple fails.

Expected Behavior

A MemoryStore can be created from a datafile containing a nested Triple.

Steps To Reproduce

Create MemoryStore with persist=true.
Add a statement involving a nested Triple.
Shutdown MemoryStore.
Create MemoryStore from datafile.

Exception in thread "main" java.lang.ClassCastException: class org.eclipse.rdf4j.model.impl.SimpleTriple cannot be cast to class org.eclipse.rdf4j.sail.memory.model.MemResource (org.eclipse.rdf4j.model.impl.SimpleTriple and org.eclipse.rdf4j.sail.memory.model.MemResource are in unnamed module of loader 'app')
2024-01-03T13:28:27.689776800Z at org.eclipse.rdf4j.sail.memory.FileIO.readStatement(FileIO.java:256)
2024-01-03T13:28:27.689938600Z at org.eclipse.rdf4j.sail.memory.FileIO.read(FileIO.java:183)
2024-01-03T13:28:27.689956200Z at org.eclipse.rdf4j.sail.memory.MemoryStore.initializeInternal(MemoryStore.java:289)
2024-01-03T13:28:27.689972100Z at org.eclipse.rdf4j.sail.helpers.AbstractSail.init(AbstractSail.java:183)
2024-01-03T13:28:27.689990100Z at org.eclipse.rdf4j.repository.sail.SailRepository.initializeInternal(SailRepository.java:158)

Version

4.3.8

Are you interested in contributing a solution yourself?

None

Anything else?

The root cause of this is line

rdf4j/core/sail/memory/src/main/java/org/eclipse/rdf4j/sail/memory/FileIO.java

Line 323 in d8bdc75

return RDFStarUtil.fromRDFEncodedValue(rdfStarEncodedTriple);

where SimpleValueFactory is used to convert an encoded triple IRI to a nested Triple. This will then cause a class cast exception on line

rdf4j/core/sail/memory/src/main/java/org/eclipse/rdf4j/sail/memory/FileIO.java

Line 256 in d8bdc75

MemResource memSubj = (MemResource) readValue(dataIn);

RDFStarUtil should contain methods that take the ValueFactory to use so that the MemoryStore can pass in its ValueFactory.

[hmottestad]

@pulquero Thanks for figuring out this bug! It should be fixed in 4.3.9.

Btw. I noticed that you don't have a name in your Github profile. We like to credit people for bug reports and fixes in the release notes on rdf4j.org, if you add a name to your Github profile then we will use that when we credit you in the release notes.