[JENA-1941] Parsed query cannot get serialized

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: Jena 3.16.0
• Fix Version/s: Jena 3.17.0
• Component/s: ARQ, Jena
• Labels: Serializer parser

Environment

Oracle jdk-14.0.1

• Assignee: Andy Seaborne
• Reporter: Michael Cochez
• Created: 30/Jul/20 16:54
• Updated: 01/Dec/20 14:32
• Resolved: 10/Aug/20 13:09

Description

The following query can be parsed, but cannot be serialized back:

import org.apache.jena.query.Query;
import org.apache.jena.query.QueryFactory;

public class MinimalTest {
	public static void main(String[] args) {
		String queryString = "SELECT ?a WHERE { <%s> <http://ex.com> <http://ex.com> }";
		Query q = QueryFactory.create(queryString);
		String serialized = q.serialize();
		System.out.println(serialized);
	}
}

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: begin 0, end 51, length 50
	at java.base/java.lang.String.checkBoundsBeginEnd(String.java:3756)
	at java.base/java.lang.String.substring(String.java:1902)
	at org.apache.jena.shared.impl.PrefixMappingImpl.qnameFor(PrefixMappingImpl.java:235)
	at org.apache.jena.sparql.util.FmtUtils.prefixFor(FmtUtils.java:494)
	at org.apache.jena.sparql.util.FmtUtils.stringForURI(FmtUtils.java:448)
	at org.apache.jena.sparql.util.FmtUtils.stringForURI(FmtUtils.java:431)
	at org.apache.jena.sparql.util.FmtUtils.stringForNode(FmtUtils.java:374)
	at org.apache.jena.sparql.util.FmtUtils.stringForNode(FmtUtils.java:348)
	at org.apache.jena.sparql.serializer.FormatterBase.slotToString(FormatterBase.java:57)
	at org.apache.jena.sparql.serializer.FormatterElement.setWidths(FormatterElement.java:615)
	at org.apache.jena.sparql.serializer.FormatterElement.formatTriples(FormatterElement.java:503)
	at org.apache.jena.sparql.serializer.FormatterElement.flush(FormatterElement.java:558)
	at org.apache.jena.sparql.serializer.FormatterElement.visit(FormatterElement.java:165)
	at org.apache.jena.sparql.syntax.ElementPathBlock.visit(ElementPathBlock.java:94)
	at org.apache.jena.sparql.serializer.FormatterElement.visit(FormatterElement.java:321)
	at org.apache.jena.sparql.syntax.ElementGroup.visit(ElementGroup.java:120)
	at org.apache.jena.sparql.serializer.FormatterElement.visitAsGroup(FormatterElement.java:453)
	at org.apache.jena.sparql.serializer.QuerySerializer.visitQueryPattern(QuerySerializer.java:207)
	at org.apache.jena.query.Query.visit(Query.java:770)
	at org.apache.jena.query.Query.serialize(Query.java:928)
	at org.apache.jena.query.Query.serialize(Query.java:905)
	at org.apache.jena.query.Query.serialize(Query.java:895)
	at org.apache.jena.query.Query.serialize(Query.java:856)
	at MinimalTest.main(MinimalTest.java:10)

I am not entirely sure whether it is

1. The query which is invalid, in which case there is a bug in the parser
2. The serialization which should not fail, in which case the serializer has a bug.