Many tests fail with NullPointerError if a representation is an empty graph

[no-reply]

The string "" is a valid Turtle representation of a resource, but at least 6 tests fail with errors like the following if that is returned for a newly created resource:

[FAILURE] BasicContainerTest.testGetResourceAcceptTurtle

LDP servers must respond with a Turtle representation of the requested LDP-RS
when the request includes an Accept header specifying text/turtle, unless HTTP
content negotiation requires a different outcome [turtle].

java.lang.NullPointerException
    at com.jayway.restassured.internal.support.CloseHTTPClientConnectionInputStreamWrapper.read(CloseHTTPClientConnectionInputStreamWrapper.java:49)
    at java.io.FilterInputStream.read(FilterInputStream.java:133)
    at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:283)
    at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:325)
    at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:177)
    at java.io.InputStreamReader.read(InputStreamReader.java:184)
    at java.io.Reader.read(Reader.java:140)
    at org.apache.jena.atlas.io.CharStreamBuffered$SourceReader.fill(CharStreamBuffered.java:77)
    at org.apache.jena.atlas.io.CharStreamBuffered.fillArray(CharStreamBuffered.java:154)
    at org.apache.jena.atlas.io.CharStreamBuffered.advance(CharStreamBuffered.java:137)
    at org.apache.jena.atlas.io.PeekReader.advanceAndSet(PeekReader.java:241)
    at org.apache.jena.atlas.io.PeekReader.init(PeekReader.java:235)
    at org.apache.jena.atlas.io.PeekReader.peekChar(PeekReader.java:157)
    at org.apache.jena.atlas.io.PeekReader.makeUTF8(PeekReader.java:98)
    at org.apache.jena.riot.tokens.TokenizerFactory.makeTokenizerUTF8(TokenizerFactory.java:41)
    at org.apache.jena.riot.RiotReader.createParser(RiotReader.java:138)
    at org.apache.jena.riot.RDFParserRegistry$ReaderRIOTLang.read(RDFParserRegistry.java:164)
    at org.apache.jena.riot.RDFDataMgr.process(RDFDataMgr.java:859)
    at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:255)
    at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:241)
    at org.apache.jena.riot.adapters.RDFReaderRIOT.read(RDFReaderRIOT.java:70)
    at com.hp.hpl.jena.rdf.model.impl.ModelCom.read(ModelCom.java:277)
    at org.w3.ldp.testsuite.mapper.RdfObjectMapper.deserialize(RdfObjectMapper.java:50)
    at com.jayway.restassured.mapper.ObjectMapper$deserialize$0.call(Unknown Source)
    at com.jayway.restassured.internal.RestAssuredResponseOptionsGroovyImpl.as(RestAssuredResponseOptionsGroovyImpl.groovy:218)
    at com.jayway.restassured.internal.RestAssuredResponseOptionsImpl.as(RestAssuredResponseOptionsImpl.java:161)
    at org.w3.ldp.testsuite.test.RdfSourceTest.testGetResourceAcceptTurtle(RdfSourceTest.java:290)
    at org.w3.ldp.testsuite.LdpTestSuite.run(LdpTestSuite.java:379)
    at org.w3.ldp.testsuite.LdpTestSuite.executeTestSuite(LdpTestSuite.java:415)
    at org.w3.ldp.testsuite.LdpTestSuite.executeTestSuite(LdpTestSuite.java:407)
    at org.w3.ldp.testsuite.RunLdpTestSuite.main(RunLdpTestSuite.java:26)
... Removed 21 stack frames

[no-reply]

This arose while working on https://github.com/ruby-rdf/rdf-ldp. Because this project includes library with middleware for building your own LDP server behavior, the design avoids adding triples to representations except where required by the LDP spec.

Unless we interpret the requirement to respond with a turtle representation as a requirement to respond with a non-empty representation, this seems like a bug in the test suite.