[LUCENE-3279] Allow CFS be empty

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.4, 4.0-ALPHA
• Fix Version/s: 3.4, 4.0-ALPHA
• Component/s: core/store
• Lucene Fields: New, Patch Available
• Assignee: Simon Willnauer
• Reporter: Simon Willnauer
• Created: 06/Jul/11 12:15
• Updated: 28/Aug/22 12:52
• Resolved: 07/Jul/11 11:47

Description

since we changed CFS semantics slightly closing a CFS directory on an error can lead to an exception. Yet, an empty CFS is still a valid CFS so for consistency we should allow CFS to be empty.
here is an example:

1 tests failed.
REGRESSION:  org.apache.lucene.index.TestIndexWriterOnDiskFull.testAddDocumentOnDiskFull

Error Message:
CFS has no entries

Stack Trace:
java.lang.IllegalStateException: CFS has no entries
       at org.apache.lucene.store.CompoundFileWriter.close(CompoundFileWriter.java:139)
       at org.apache.lucene.store.CompoundFileDirectory.close(CompoundFileDirectory.java:181)
       at org.apache.lucene.store.DefaultCompoundFileDirectory.close(DefaultCompoundFileDirectory.java:58)
       at org.apache.lucene.index.SegmentMerger.createCompoundFile(SegmentMerger.java:139)
       at org.apache.lucene.index.IndexWriter.mergeMiddle(IndexWriter.java:4252)
       at org.apache.lucene.index.IndexWriter.merge(IndexWriter.java:3863)
       at org.apache.lucene.index.SerialMergeScheduler.merge(SerialMergeScheduler.java:37)
       at org.apache.lucene.index.IndexWriter.maybeMerge(IndexWriter.java:2715)
       at org.apache.lucene.index.IndexWriter.maybeMerge(IndexWriter.java:2710)
       at org.apache.lucene.index.IndexWriter.maybeMerge(IndexWriter.java:2706)
       at org.apache.lucene.index.IndexWriter.flush(IndexWriter.java:3513)
       at org.apache.lucene.index.IndexWriter.addDocument(IndexWriter.java:2064)
       at org.apache.lucene.index.IndexWriter.addDocument(IndexWriter.java:2031)
       at org.apache.lucene.index.TestIndexWriterOnDiskFull.addDoc(TestIndexWriterOnDiskFull.java:539)
       at org.apache.lucene.index.TestIndexWriterOnDiskFull.testAddDocumentOnDiskFull(TestIndexWriterOnDiskFull.java:74)
       at org.apache.lucene.util.LuceneTestCase$LuceneTestCaseRunner.runChild(LuceneTestCase.java:1277)
       at org.apache.lucene.util.LuceneTestCase$LuceneTestCaseRunner.runChild(LuceneTestCase.java:1195)