Add failing test for add nested in an open search

This is because Net::LDAP::Connection#add calls read without queueing,
meaning it can read the wrong message off the socket.

Author: mtodd

test/integration/test_open.rb

@@ -21,6 +21,10 @@ def test_binds_with_open
     assert_equal 1, events.size
   end
 
+  # NOTE: query for two or more entries so that the socket must be read
+  # multiple times.
+  # See The Problem: https://github.com/ruby-ldap/ruby-net-ldap/issues/136
+
   def test_nested_search_without_open
     entries = []
     nested_entry = nil
@@ -48,4 +52,37 @@ def test_nested_search_with_open
     assert_equal "user3", nested_entry.uid.first
     assert_equal %w(user1 user2), entries
   end
+
+  def test_nested_add_with_open
+    entries = []
+    nested_entry = nil
+
+    dn = "uid=nested-open-added-user1,ou=People,dc=rubyldap,dc=com"
+    attrs = {
+      objectclass: %w(top inetOrgPerson organizationalPerson person),
+      uid:  "nested-open-added-user1",
+      cn:   "nested-open-added-user1",
+      sn:   "nested-open-added-user1",
+      mail: "nested-open-added-user1@rubyldap.com"
+    }
+
+    @ldap.authenticate "cn=admin,dc=rubyldap,dc=com", "passworD1"
+    @ldap.delete dn: dn
+
+    @ldap.open do
+      @ldap.search(filter: "(|(uid=user1)(uid=user2))", base: "ou=People,dc=rubyldap,dc=com") do |entry|
+        entries << entry.uid.first
+
+        nested_entry ||= begin
+          assert @ldap.add(dn: dn, attributes: attrs), @ldap.get_operation_result.inspect
+          @ldap.search(base: dn, scope: Net::LDAP::SearchScope_BaseObject).first
+        end
+      end
+    end
+
+    assert_equal %w(user1 user2), entries
+    assert_equal "nested-open-added-user1", nested_entry.uid.first
+  ensure
+    @ldap.delete dn: dn
+  end
 end