8.5.2 Fix a bug where iterator can return incorrect data for DeleteRange() users (#11785)

This should only affect iterator when
- user uses DeleteRange(), 
- An iterator from level L has a non-ok status (such non-ok status may not be caught before the bug fix in https://github.com/facebook/rocksdb/pull/11783), and
- A range tombstone covers a key from level > L and triggers a reseek sets the status_ to OK in SeekImpl()/SeekPrevImpl() e.g. https://github.com/facebook/rocksdb/blob/bd6a8340c3a2db764620e90b3ac5be173fc68a0c/table/merging_iterator.cc#L801

HISTORY.md

 # Rocksdb Change Log
 > NOTE: Entries for next release do not go here. Follow instructions in `unreleased_history/README.txt`
 
+## 8.5.2 (08/31/2023)
+### Bug fixes
+* Fix a bug where iterator may return incorrect result for DeleteRange() users if there was an error reading from a file.
+
 ## 8.5.1 (08/31/2023)
 ### Bug fixes
 * Fix a bug where if there is an error reading from offset 0 of a file from L1+ and that the file is not the first file in the sorted run, data can be lost in compaction and read/scan can return incorrect results.

include/rocksdb/version.h

@@ -13,7 +13,7 @@
 // minor or major version number planned for release.
 #define ROCKSDB_MAJOR 8
 #define ROCKSDB_MINOR 5
-#define ROCKSDB_PATCH 1
+#define ROCKSDB_PATCH 2
 
 // Do not use these. We made the mistake of declaring macros starting with
 // double underscore. Now we have to live with our choice. We'll deprecate these

table/merging_iterator.cc

@@ -308,6 +308,7 @@ class MergingIterator : public InternalIterator {
     // holds after this call, and minHeap_.top().iter points to the
     // first key >= target among children_ that is not covered by any range
     // tombstone.
+    status_ = Status::OK();
     SeekImpl(target);
     FindNextVisibleKey();
 
@@ -321,6 +322,7 @@ class MergingIterator : public InternalIterator {
   void SeekForPrev(const Slice& target) override {
     assert(range_tombstone_iters_.empty() ||
            range_tombstone_iters_.size() == children_.size());
+    status_ = Status::OK();
     SeekForPrevImpl(target);
     FindPrevVisibleKey();
 
@@ -798,7 +800,6 @@ void MergingIterator::SeekImpl(const Slice& target, size_t starting_level,
     active_.erase(active_.lower_bound(starting_level), active_.end());
   }
 
-  status_ = Status::OK();
   IterKey current_search_key;
   current_search_key.SetInternalKey(target, false /* copy */);
   // Seek target might change to some range tombstone end key, so
@@ -1083,7 +1084,6 @@ void MergingIterator::SeekForPrevImpl(const Slice& target,
     active_.erase(active_.lower_bound(starting_level), active_.end());
   }
 
-  status_ = Status::OK();
   IterKey current_search_key;
   current_search_key.SetInternalKey(target, false /* copy */);
   // Seek target might change to some range tombstone end key, so