Fixed socket states in tests

tests/test_pair.cpp

@@ -39,6 +39,9 @@ int main ()
     {
         const string returned = zmqtestutil::ping_pong (p, expect);
         assert (expect == returned);
+        //  Adjust socket state so that poll shows only 1 pending message.
+        zmq::message_t mx ;
+        p.first->recv(&mx, 0);
     }
 
     {

tests/test_reqrep.cpp

@@ -39,6 +39,9 @@ int main()
     {
         const string returned = zmqtestutil::ping_pong (p, expect);
         assert (expect == returned);
+        //  Adjust socket state, so that first is clean for another send.
+        zmq::message_t mx ;
+        p.first->recv(&mx, 0);
     }
 
     {

tests/testutil.hpp

@@ -55,8 +55,12 @@ namespace zmqtestutil
         zmq::message_t pong;
         s2.recv (&pong, 0);
 
+        //  Send message via s2, so state is clean in case of req/rep.
+        std::string ret((char *)pong.data(), pong.size());
+        s2.send(pong, 0);
+
         //  Return received data as std::string.
-        return std::string ((char*) pong.data(), pong.size());
+        return ret ;
     }
 
 }