NullPointerException when parsing SPARQL update with multiple expressions one of hich has SERVICE

[damyan-ognyanov]

If a SPARQL update have multiple update expressions (delimited with ';') and one of those have SERVICE, a NullPointerException is thrown during parsing.

for instance:

PREFIX family: <http://examples.ontotext.com/family#>
DROP ALL ;
INSERT {
    family:Alice family:knows family:Bob .
}
WHERE {
    SERVICE <repository:1> {
        family:Alice family:knows family:Bob .
    }
}

we got:

java.lang.NullPointerException: null
        at org.eclipse.rdf4j.query.parser.sparql.ast.ASTServiceGraphPattern.getPatternString(ASTServiceGraphPattern.java:67)
        at org.eclipse.rdf4j.query.parser.sparql.TupleExprBuilder.visit(TupleExprBuilder.java:1079)
        at org.eclipse.rdf4j.query.parser.sparql.ast.ASTServiceGraphPattern.jjtAccept(ASTServiceGraphPattern.java:43)
        at org.eclipse.rdf4j.query.parser.sparql.TupleExprBuilder.visit(TupleExprBuilder.java:1046)
        at org.eclipse.rdf4j.query.parser.sparql.ast.ASTGraphPatternGroup.jjtAccept(ASTGraphPatternGroup.java:24)
        at org.eclipse.rdf4j.query.parser.sparql.ast.SimpleNode.childrenAccept(SimpleNode.java:152)
        at org.eclipse.rdf4j.query.parser.sparql.AbstractASTVisitor.visit(AbstractASTVisitor.java:730)
        at org.eclipse.rdf4j.query.parser.sparql.ast.ASTWhereClause.jjtAccept(ASTWhereClause.java:24)
        at org.eclipse.rdf4j.query.parser.sparql.UpdateExprBuilder.visit(UpdateExprBuilder.java:298)
        at org.eclipse.rdf4j.query.parser.sparql.UpdateExprBuilder.visit(UpdateExprBuilder.java:66)
        at org.eclipse.rdf4j.query.parser.sparql.ast.ASTModify.jjtAccept(ASTModify.java:25)
        at org.eclipse.rdf4j.query.parser.sparql.SPARQLParser.parseUpdate(SPARQLParser.java:118)
        at org.eclipse.rdf4j.query.parser.QueryParserUtil.parseUpdate(QueryParserUtil.java:76)