The Couchbase::Bucket class hasn't implemented the #dup method. So it caused SEGFAULT. The patch is implementing correct function, which copy the internals and initializes new connection.

Issues: RCBC-64

make object_space gc protector per-bucket object

previous version provided not completely thread-safe bucket instance, because it was sharing global hash for protecting objects, created in extension, from garbage collecting.

Issues: RCBC-60

The flags might be reset if caller will use Couchbase::Bucket#cas operation. Here is IRB session demostrating the issue:

irb> Couchbase.bucket.set("foo", "bar", :flags => 0x100)
17982951084586893312
irb> Couchbase.bucket.cas("foo") { "baz" }
1712422461213442048
irb> Couchbase.bucket.get("foo", :extended => true)
["baz", 0, 1712422461213442048]

Issues: RCBC-59