org.apache.jena.fuseki.servlets.ActionErrorException: Cannot read field "succ" because "n" is null

### Version

5.0.0

### What happened?

# Steps to Reproduce
1. Create a new dataset via `curl -X POST 'http://localhost:3030/$/datasets' --upload-file ./dsConfigTemplate.ttl --header "Content-Type: text/turtle"` where `dsConfigTemplate.ttl` is:

```
# https://apothem.blog/apache-jena-fuseki-adding-reasoning-and-full-text-search-capabilities-to-a-dataset.html
PREFIX :
PREFIX fuseki:
PREFIX ja:
PREFIX rdf:
PREFIX rdfs:
PREFIX tdb2:

:tdb_dataset_readwrite
rdf:type tdb2:DatasetTDB2;
tdb2:location "/fuseki/databases/ds" . # <-- Change ds to the name of the datastore

:service_tdb_all rdf:type fuseki:Service;
rdfs:label "TDB2 ds";
fuseki:dataset :dataset ;
fuseki:endpoint [ fuseki:name "get";
fuseki:operation fuseki:gsp-r
];
fuseki:endpoint [ fuseki:operation fuseki:gsp-rw ];
fuseki:endpoint [ fuseki:operation fuseki:update ];
fuseki:endpoint [ fuseki:name "update";
fuseki:operation fuseki:update
];
fuseki:endpoint [ fuseki:name "sparql";
fuseki:operation fuseki:query
];
fuseki:endpoint [ fuseki:operation fuseki:query ];
fuseki:endpoint [ fuseki:name "data";
fuseki:operation fuseki:gsp-rw
];
fuseki:endpoint [ fuseki:name "query";
fuseki:operation fuseki:query
];
fuseki:name "ds" . # <-- Change ds to the name of the datastore
:dataset a ja:RDFDataset ;
ja:defaultGraph :model_inf .

:model_inf a ja:InfModel ;
ja:baseModel :graph ;
ja:reasoner [
ja:reasonerURL
] .

:graph rdf:type tdb2:GraphTDB ;
tdb2:dataset :tdb_dataset_readwrite ;
.
```
2. Via the web interface's edit tab, replace all the triples in the default graph with:
```
PREFIX rdf:
PREFIX rdfs:

rdfs:range rdf:type rdf:Property , rdfs:Resource;
rdfs:comment "A range of the subject property.";
rdfs:domain rdf:Property;
rdfs:isDefinedBy rdfs:;
rdfs:label "range";
rdfs:range rdfs:Class;
rdfs:seeAlso rdfs:;
rdfs:subPropertyOf rdfs:range .

rdfs:subPropertyOf rdf:type rdf:Property , rdfs:Resource;
rdfs:comment "The subject is a subproperty of a property.";
rdfs:domain rdf:Property;
rdfs:isDefinedBy rdfs:;
rdfs:label "subPropertyOf";
rdfs:range rdf:Property;
rdfs:seeAlso rdfs:;
rdfs:subPropertyOf rdfs:subPropertyOf .
```
3. In the query tab of the web interface, change the `query` endpoint to `update` and run this query:
```
DELETE {?s ?p ?o} WHERE { VALUES ?s{ }
?s ?p ?o .
}
```
4. Observe Error `Cannot read field "succ" because "n" is null`

### Relevant output and stacktrace

```shell
org.apache.jena.fuseki.servlets.ActionErrorException: Cannot read field "succ" because "n" is null
at org.apache.jena.fuseki.servlets.ServletOps.errorOccurred(ServletOps.java:275) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.SPARQL_Update.execute(SPARQL_Update.java:259) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.SPARQL_Update.executeBody(SPARQL_Update.java:191) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.SPARQL_Update.execute(SPARQL_Update.java:106) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.ActionService.executeLifecycle(ActionService.java:58) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.SPARQL_Update.execPost(SPARQL_Update.java:91) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.ActionProcessor.process(ActionProcessor.java:34) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.ActionBase.process(ActionBase.java:54) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.ActionExecLib.execActionSub(ActionExecLib.java:127) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.ActionExecLib.execAction(ActionExecLib.java:101) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.server.Dispatcher.dispatchAction(Dispatcher.java:240) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.server.Dispatcher.process(Dispatcher.java:230) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.server.Dispatcher.dispatch(Dispatcher.java:148) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.FusekiFilter.doFilter(FusekiFilter.java:49) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.ee10.servlet.FilterHolder.doFilter(FilterHolder.java:205) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.ee10.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1586) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:65) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:109) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:138) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:156) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:70) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:109) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:138) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:156) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:70) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:463) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.AbstractShiroFilter.lambda$doFilterInternal$0(AbstractShiroFilter.java:378) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:91) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:84) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:389) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:376) ~[fuseki-server.jar:5.0.0]
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:156) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.ee10.servlet.FilterHolder.doFilter(FilterHolder.java:205) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.ee10.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1586) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.CrossOriginFilter.handle(CrossOriginFilter.java:348) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.CrossOriginFilter.doFilter(CrossOriginFilter.java:301) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.ee10.servlet.FilterHolder.doFilter(FilterHolder.java:208) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.ee10.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1586) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.ee10.servlet.ServletHandler$MappedServlet.handle(ServletHandler.java:1547) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.ee10.servlet.ServletChannel.dispatch(ServletChannel.java:814) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.ee10.servlet.ServletChannel.handle(ServletChannel.java:431) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.ee10.servlet.ServletHandler.handle(ServletHandler.java:464) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:571) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.ee10.servlet.SessionHandler.handle(SessionHandler.java:703) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.server.handler.ContextHandler.handle(ContextHandler.java:765) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.server.handler.gzip.GzipHandler.handle(GzipHandler.java:597) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.server.Server.handle(Server.java:179) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.server.internal.HttpChannelState$HandlerInvoker.run(HttpChannelState.java:619) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.server.internal.HttpConnection.onFillable(HttpConnection.java:411) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:322) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:99) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.io.SelectableChannelEndPoint$1.run(SelectableChannelEndPoint.java:53) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.runTask(AdaptiveExecutionStrategy.java:478) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.consumeTask(AdaptiveExecutionStrategy.java:441) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.tryProduce(AdaptiveExecutionStrategy.java:293) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.run(AdaptiveExecutionStrategy.java:201) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:410) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:971) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.doRunJob(QueuedThreadPool.java:1201) ~[fuseki-server.jar:5.0.0]
at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1156) ~[fuseki-server.jar:5.0.0]
at java.base/java.lang.Thread.run(Unknown Source) [?:?]
Caused by: java.lang.NullPointerException: Cannot read field "succ" because "n" is null
at org.apache.jena.reasoner.transitiveReasoner.TransitiveGraphCache.processDeletes(TransitiveGraphCache.java:439) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.reasoner.transitiveReasoner.TransitiveGraphCache.find(TransitiveGraphCache.java:546) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.reasoner.transitiveReasoner.TransitiveEngine.cacheSubPropUtility(TransitiveEngine.java:385) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.reasoner.transitiveReasoner.TransitiveEngine.delete(TransitiveEngine.java:276) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.reasoner.rulesys.FBRuleInfGraph.performDelete(FBRuleInfGraph.java:658) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.graph.impl.GraphBase.delete(GraphBase.java:181) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.sparql.core.DatasetGraphCollection.delete(DatasetGraphCollection.java:53) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.sparql.modify.UpdateEngineWorker.deleteFromDatasetGrap
14:14:38.180 › Fuseki: h(UpdateEngineWorker.java:506) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.sparql.modify.UpdateEngineWorker.lambda$execDelete$8(UpdateEngineWorker.java:474) ~[fuseki-server.jar:5.0.0]
at java.base/java.util.ArrayList$Itr.forEachRemaining(Unknown Source) ~[?:?]
at org.apache.jena.atlas.iterator.IteratorFlatMap.lambda$forEachRemaining$0(IteratorFlatMap.java:94) ~[fuseki-server.jar:5.0.0]
at java.base/java.util.ArrayList$Itr.forEachRemaining(Unknown Source) ~[?:?]
at org.apache.jena.atlas.iterator.IteratorFlatMap.forEachRemaining(IteratorFlatMap.java:90) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.sparql.modify.UpdateEngineWorker.execDelete(UpdateEngineWorker.java:474) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.sparql.modify.UpdateEngineWorker.execDelete(UpdateEngineWorker.java:463) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.sparql.modify.UpdateEngineWorker.visit(UpdateEngineWorker.java:384) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.sparql.modify.request.UpdateModify.visit(UpdateModify.java:100) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.sparql.modify.UpdateVisitorSink.send(UpdateVisitorSink.java:45) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.sparql.modify.UpdateVisitorSink.send(UpdateVisitorSink.java:31) ~[fuseki-server.jar:5.0.0]
at java.base/java.util.ArrayList$Itr.forEachRemaining(Unknown Source) ~[?:?]
at java.base/java.util.Collections$UnmodifiableCollection$1.forEachRemaining(Unknown Source) ~[?:?]
at org.apache.jena.atlas.iterator.Iter.sendToSink(Iter.java:776) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.sparql.modify.UpdateProcessorBase.execute(UpdateProcessorBase.java:60) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.sparql.exec.UpdateExecDataset.execute(UpdateExecDataset.java:37) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.update.UpdateAction.execute$(UpdateAction.java:230) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.update.UpdateAction.execute(UpdateAction.java:195) ~[fuseki-server.jar:5.0.0]
at org.apache.jena.fuseki.servlets.SPARQL_Update.execute(SPARQL_Update.java:231) ~[fuseki-server.jar:5.0.0]
... 59 more
[2024-08-01 14:14:38] Fuseki INFO [304] 500 Server Error (207 ms)
```

### Are you interested in making a pull request?

No

Reproduce the failure with the dataset configuration and DELETE query described in the issue, then start at org.apache.jena.reasoner.transitiveReasoner.TransitiveGraphCache.processDeletes in TransitiveGraphCache.java:439 and follow its callers through TransitiveEngine.delete. Add coverage for this deletion scenario and verify that it completes without the NullPointerException.

Written by the indexing model from the issue text.