Johannes Kloos created LUCENE-8666:
--------------------------------------
Summary: NPE in o.a.l.codecs.perfield.PerFieldPostingsFormat
Key: LUCENE-8666
URL: https://issues.apache.org/jira/browse/LUCENE-8666
Project: Lucene - Core
Issue Type: Bug
Components: core/codecs
Affects Versions: 7.5, master (9.0)
Environment: *
Running on Unix, using a recent git checkout of master and the films example
database.
h2. Steps to reproduce
* Build commit ea2c8ba of Solr as described in the section below.
* Build the films collection as described below.
* Start the server using the command “./bin/solr start -f -p 8983 -s /tmp/home”
* Request the URL above.
h2. Compiling the server
git clone [https://github.com/apache/lucene-solr]
cd lucene-solr
git checkout ea2c8ba
ant compile
cd solr
ant server
h2. Building the collection
We followed Exercise 2 from the SOLR quick start tutorial
([http://lucene.apache.org/solr/guide/7_5/solr-tutorial.html#exercise-2]). The
attached file (home.zip) gives the contents of folder /tmp/home that you will
obtain by following the steps below.
{{}}{{mkdir -p /tmp/home}}
{{ echo '<?xml version="1.0" encoding="UTF-8" ?><solr></solr>' >
/tmp/home/solr.xml}}
In one terminal start a Solr instance in foreground:
{{./bin/solr start -f -p 8983 -s /tmp/home}}
In another terminal, create a collection of movies, with no shards and no
replication:
{{bin/solr create -c films}}
{{ curl -X POST -H 'Content-type:application/json' --data-binary
'\{"add-field": {"name":"name", "type":"text_general", "multiValued":false,
"stored":true}}' [http://localhost:8983/solr/films/schema]}}}}
{{curl -X POST -H 'Content-type:application/json' --data-binary
'{"add-copy-field" : {"source":"*","dest":"_text_"}}{{'
[http://localhost:8983/solr/films/schema]}}'}}
{{./bin/post -c films example/films/films.json}}
{{ }}
Reporter: Johannes Kloos
Attachments: 0001-Fix-NullPointerException.patch, home.zip
Requesting this URL in SOLR gives a 500 error with a stack trace pointing to
Lucene:
{{http://localhost:8983/solr/films/select?q=\{!complexphrase}genre:"-om*"}}
The stack trace is (cut down to the reasonably relevant part):
{{java.lang.NullPointerException\n\tat
java.util.TreeMap.getEntry(TreeMap.java:347)
at java.util.TreeMap.get(TreeMap.java:278)
at
org.apache.lucene.codecs.perfield.PerFieldPostingsFormat$FieldsReader.terms(PerFieldPostingsFormat.java:311)
at org.apache.lucene.index.CodecReader.terms(CodecReader.java:106)
at org.apache.lucene.index.FilterLeafReader.terms(FilterLeafReader.java:351)
at
org.apache.lucene.index.ExitableDirectoryReader$ExitableFilterAtomicReader.terms(ExitableDirectoryReader.java:91)
at
org.apache.lucene.search.spans.SpanNearQuery$SpanNearWeight.getSpans(SpanNearQuery.java:208)
at
org.apache.lucene.search.spans.SpanNotQuery$SpanNotWeight.getSpans(SpanNotQuery.java:127)
at org.apache.lucene.search.spans.SpanWeight.scorer(SpanWeight.java:135)
at org.apache.lucene.search.spans.SpanWeight.scorer(SpanWeight.java:46)
at org.apache.lucene.search.Weight.bulkScorer(Weight.java:177)
at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:649)
at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:443)
at
org.apache.solr.search.SolrIndexSearcher.buildAndRunCollectorChain(SolrIndexSearcher.java:200)
at
org.apache.solr.search.SolrIndexSearcher.getDocListNC(SolrIndexSearcher.java:1604)}}{{The
error is actually a bit deeper and can be traced back to the
o.a.l.queryparser.complexPhrase.ComplexPhraseQueryParser class.}}
Handling this query involves constructing a SpanQuery, which happens in the
rewrite method of ComplexPhraseQueryParser. In particular, the expression is
decomposed into a BooleanQuery, which has exactly one clause, namely the
negative clause -genre:”om*”. The rewrite method then further transforms this
into a SpanQuery; in this case, it goes into the path that handles complex
queries with both positive and negative clauses. It extracts the subset of
positive clauses - note that this set of clauses is empty for this query. The
positive clauses are then combined into a SpanNearQuery (around line 340),
which is then used to build a SpanNotQuery. Further down the line, the field
attribute of the SpanNearQuery is accessed and used as an index into a TreeMap.
But since we had an empty set of positive clauses, the SpanNearQuery does not
have its field attribute set, so we get a null here - this leads to an
exception. A possible fix would be to detect the situation where we have an
empty set of positive clauses and include a single synthetic clause that
matches either everything or nothing. See attached file
0001-Fix-NullPointerException.patch.
This bug was found using [Diffblue Microservices
Testing|http://www.diffblue.com/labs]. Find more information on this [test
campaign|https://www.diffblue.com/blog/2018/12/19/diffblue-microservice-testing-a-sneak-peek-at-our-early-product-and-results].
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
