FHIR Path validation issue in integration-tests

[oliveregger]

Validate Patient against http://fhir.ch/ig/ch-elm/StructureDefinition/ChElmPatientInitials|1.3.1...java.lang.NullPointerException: Cannot invoke "String.length()" because "s" is null
at org.hl7.fhir.r5.fhirpath.FHIRPathEngine.funcLength(FHIRPathEngine.java:5754)
at org.hl7.fhir.r5.fhirpath.FHIRPathEngine.evaluateFunction(FHIRPathEngine.java:3975)
at org.hl7.fhir.r5.fhirpath.FHIRPathEngine.execute(FHIRPathEngine.java:1555)
at org.hl7.fhir.r5.fhirpath.FHIRPathEngine.execute(FHIRPathEngine.java:1567)
at org.hl7.fhir.r5.fhirpath.FHIRPathEngine.execute(FHIRPathEngine.java:1567)
at org.hl7.fhir.r5.fhirpath.FHIRPathEngine.execute(FHIRPathEngine.java:1562)
at org.hl7.fhir.r5.fhirpath.FHIRPathEngine.execute(FHIRPathEngine.java:1583)
at org.hl7.fhir.r5.fhirpath.FHIRPathEngine.evaluate(FHIRPathEngine.java:828)

[oliveregger]

is a fhir path issue when a primity type is empty but has an extension on it, see ahdis/ch-elm@28ed3f2