Enhancements

• Internal:
  • Make sure we don't reuse arrays when sending an error back #6631
  • Better default size for global index -> alias map #6504

Bug fixes

• Aggregations:
  • Fix reducing of range aggregations. #6484
  • Fix cardinality aggregation when doc values field is empty #6413
• Bulk API: Fix return of wrong request type on failed updates #6630
• Cat API: Fix NullPointerException in cat-recovery API #6190
• Core: The ignore_unavailable option should also ignore indices that are closed #6475
• Internal:
  • [Translog] Better support for partial buffer reads/writes in translog infrastructure #6576
  • [FileSystem] Use XNativeFSLockFactory instead of the buggy Lucene 4.8.1 version #6424
• Java API:
  • Fix source excludes setting if no includes were provided #6632
  • BulkRequest#add(Iterable) to support UpdateRequests #6551
• Mapping: Fix possibility of losing meta configuration on field mapping update #5053
• Mappings: Allow _version to use `disk` as a doc values format. #6523
• Percolator:
  • Fix memory leak when percolating with nested documents #6578
  • Fix handling of nested documents #6540
• Plugins: Fix github download link when using specific version #6321
• Query DSL: Improved explanation for match_phrase_prefix #2449
• Scripts: exposed _uid, _id and _type fields as stored fields (_fields notation) #6406
• Search:
  • The query_string cache should returned cloned Query instances. #6733
  • Replace empty bool queries with match_all to prevent NullPointerExceptions #6722
  • Match query with operator and, cutoff_frequency and stacked tokens #6573
• Snapshot/Restore: Allow deleting of interrupted snapshot #6383
• Test: Fix possible race condition in checksum name generator #6662

Regression

• Aggregations: fix JSON response for significant terms #6535