Runtime exception when validating a file with empy name

When a variable has an empty name, the validation throws a runtime exeception as follow:

Caused by: java.lang.RuntimeException: Error evaluating constraint 'FEELParser.isVariableNameValid( name ) == false' in [Rule "NAME_INVALID" in rules.drl]
at org.drools.core.rule.constraint.MvelConstraint.evaluate(MvelConstraint.java:262)
at org.drools.core.rule.constraint.MvelConstraint.isAllowed(MvelConstraint.java:215)
at org.drools.core.reteoo.AlphaNode.assertObject(AlphaNode.java:131)
at org.drools.core.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:70)
at org.drools.core.reteoo.ObjectTypeNode.propagateAssert(ObjectTypeNode.java:316)
at org.drools.core.phreak.PropagationEntry$Insert.propagate(PropagationEntry.java:152)
at org.drools.core.phreak.PropagationEntry$Insert.execute(PropagationEntry.java:157)
at org.drools.core.phreak.SynchronizedPropagationList.flush(SynchronizedPropagationList.java:93)
at org.drools.core.phreak.SynchronizedPropagationList.flush(SynchronizedPropagationList.java:88)
at org.drools.core.common.DefaultAgenda.fireLoop(DefaultAgenda.java:1055)
at org.drools.core.common.DefaultAgenda.internalFireAllRules(DefaultAgenda.java:1018)
at org.drools.core.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1010)
at org.drools.core.impl.StatefulKnowledgeSessionImpl.internalFireAllRules(StatefulKnowledgeSessionImpl.java:1292)
at org.drools.core.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:1283)
at org.drools.core.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:1267)
at org.drools.core.impl.StatelessKnowledgeSessionImpl.execute(StatelessKnowledgeSessionImpl.java:282)
at org.kie.dmn.validation.DMNValidatorImpl.validateModel(DMNValidatorImpl.java:145)
at com.trisotech.dmn.redhat.transformation.DMN1ValidationTransformation.internalTransform(DMN1ValidationTransformation.java:64)
at com.trisotech.transformation.engine.transformation.AbstractTransformation.transform(AbstractTransformation.java:86)
... 42 more
Caused by: java.lang.NullPointerException
at org.kie.dmn.feel.parser.feel11.ParserHelper.getOriginalText(ParserHelper.java:150)
at org.kie.dmn.feel.parser.feel11.ParserHelper.defineVariable(ParserHelper.java:125)
at org.kie.dmn.feel.parser.feel11.FEEL_1_1Parser.nameDefinition(FEEL_1_1Parser.java:1459)
at org.kie.dmn.feel.parser.feel11.FEELParser.isVariableNameValid(FEELParser.java:59)
at ConditionEvaluator59c2efa132a0438abcc40f9d4d01d964.evaluate(Unknown Source)
at org.drools.core.rule.constraint.MvelConstraint.evaluate(MvelConstraint.java:260)
... 60 more