Fix merging range tombstone covering put during flush/compaction (#5406)

Summary:
Flush/compaction use `MergeUntil` which has a special code path to
handle a merge ending with a non-`Merge` point key. In particular if
that key is a `Put` we forgot to check whether it is covered by a range
tombstone. If it is covered then we must not include it in the following call
to `TimedFullMerge`.

Fixes #5392.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5406

Differential Revision: D15611144

Pulled By: sagar0

fbshipit-source-id: ba6a7863ca2d043f591de78fd0c4f4561f0c500e

diff --git a/HISTORY.md b/HISTORY.md
index b2791bee133599a5d4b81e5cc28ab17441683dfe..33ba27d664176e28fe56e84c9715600ae63ce9c1 100644 (file)
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -115,6 +115,10 @@
 * Close a WAL file before another thread deletes it.
 * Fix an assertion failure `IsFlushPending() == true` caused by one bg thread releasing the db mutex in ~ColumnFamilyData and another thread clearing `flush_requested_` flag.
 
+## 6.1.2 (6/4/2019)
+### Bug Fixes
+* Fix flush's/compaction's merge processing logic which allowed `Put`s covered by range tombstones to reappear. Note `Put`s may exist even if the user only ever called `Merge()` due to an internal conversion during compaction to the bottommost level.
+
 ## 6.1.1 (4/9/2019)
 ### New Features
 * When reading from option file/string/map, customized comparators and/or merge operators can be filled according to object registry.