Combine PRs ruby-ldap#306 & ruby-ldap#308

Author: rlue

lib/net/ldap/connection.rb

@@ -74,7 +74,8 @@ def open_connection(server)
 
   module GetbyteForSSLSocket
     def getbyte
-      getc.ord
+      (nextbyte = read(1)) or return
+      nextbyte.ord
     end
   end
 
@@ -467,6 +468,10 @@ def search(args = nil)
           end
         end
 
+        if result_pdu.nil?
+          raise Net::LDAP::ResponseMissingOrInvalidError, "response missing"
+        end
+
         # count number of pages of results
         payload[:page_count] ||= 0
         payload[:page_count]  += 1