Core dump in DB#close/DB#reopen after DB#each/DB#range

[ogibayashi]

Invoking DB#close or DB#reopen after using iterator (DB#each, DB#range) causes core dump.

2.1.2 :001 > require 'leveldb'
 => true 
2.1.2 :002 > db = LevelDB::DB.new('/disks/disk6/leveldb/range_test')   # If I does not use iterator, its OK.
 => #<LevelDB::DB:0x798290> 
2.1.2 :003 > db.reopen
 => nil 
2.1.2 :004 > db.close
 => true 
2.1.2 :005 > db = LevelDB::DB.new('/disks/disk6/leveldb/range_test')   # DB#reopen after interating, core dumped.
 => #<LevelDB::DB:0x78b900> 
2.1.2 :006 > db.each{|k,v|  break}
 => #<LevelDB::Iterator:0x7839a8> 
2.1.2 :007 > db.reopen
irb: version_set.cc:715: leveldb::VersionSet::~VersionSet(): Assertion `dummy_versions_.next_ == &dummy_versions_' failed.
Aborted (core dumped)

If I close iterator explicitly, it worked.

2.1.2 :001 > require 'leveldb'
 => true 
2.1.2 :002 > db = LevelDB::DB.new('/disks/disk6/leveldb/range_test')
 => #<LevelDB::DB:0x4be060> 
2.1.2 :003 > it = db.each
 => #<LevelDB::Iterator:0x4ba2bc> 
2.1.2 :004 > it.each{|k,v|   break }
 => nil 
2.1.2 :005 > it.instance_eval{ LevelDB::C.iter_destroy(@_iterator) }
 => nil 
2.1.2 :006 > db.close
 => true 

Relating to this LevelDB Issue?
https://code.google.com/p/leveldb/issues/detail?id=136