Problem: can't unbind with bound addr with IPv6

Solution: try to resolve the TCP endpoint passed by the user in the
zmq_unbind call before giving up, if it doesn't match.
This fixes a breakage in the API, where after a call to
zmq_bind(s, "tcp://127.0.0.1:9999") with IPv6 enabled on s would
result in the call to zmq_unbind(s, "tcp://127.0.0.1:9999") failing.
Add more test cases to increase coverage on all combinations of TCP
endpoints.

src/socket_base.cpp

@@ -1029,8 +1029,38 @@ int zmq::socket_base_t::term_endpoint (const char *addr_)
         return 0;
     }
 
+    std::string resolved_addr = std::string (addr_);
+    std::pair <endpoints_t::iterator, endpoints_t::iterator> range;
+
+    // The resolved last_endpoint is used as a key in the endpoints map.
+    // The address passed by the user might not match in the TCP case due to
+    // IPv4-in-IPv6 mapping (EG: tcp://[::ffff:127.0.0.1]:9999), so try to
+    // resolve before giving up. Given at this stage we don't know whether a
+    // socket is connected or bound, try with both.
+    if (protocol == "tcp") {
+        range = endpoints.equal_range (resolved_addr);
+        if (range.first == range.second) {
+            tcp_address_t *tcp_addr = new (std::nothrow) tcp_address_t ();
+            alloc_assert (tcp_addr);
+            rc = tcp_addr->resolve (address.c_str (), false, options.ipv6);
+
+            if (rc == 0) {
+                tcp_addr->to_string (resolved_addr);
+                range = endpoints.equal_range (resolved_addr);
+
+                if (range.first == range.second) {
+                    rc = tcp_addr->resolve (address.c_str (), true, options.ipv6);
+                    if (rc == 0) {
+                        tcp_addr->to_string (resolved_addr);
+                    }
+                }
+            }
+            LIBZMQ_DELETE(tcp_addr);
+        }
+    }
+
     //  Find the endpoints range (if any) corresponding to the addr_ string.
-    std::pair <endpoints_t::iterator, endpoints_t::iterator> range = endpoints.equal_range (std::string (addr_));
+    range = endpoints.equal_range (resolved_addr);
     if (range.first == range.second) {
         errno = ENOENT;
         EXIT_MUTEX ();

tests/test_unbind_wildcard.cpp

@@ -22,11 +22,16 @@
 int main (void)
 {
     setup_test_environment();
+    int ipv6 = is_ipv6_available ();
     void *ctx = zmq_ctx_new ();
     assert (ctx);
 
+    /* Address wildcard, IPv6 disabled */
     void *sb = zmq_socket (ctx, ZMQ_REP);
     assert (sb);
+    void *sc = zmq_socket (ctx, ZMQ_REQ);
+    assert (sc);
+
     int rc = zmq_bind (sb, "tcp://*:5555");
     assert (rc == 0);
 
@@ -35,12 +40,235 @@ int main (void)
     rc = zmq_getsockopt (sb, ZMQ_LAST_ENDPOINT, endpoint, &endpoint_len);
     assert (rc == 0);
 
+    rc = zmq_connect (sc, endpoint);
+    assert (rc == 0);
+
+    bounce (sb, sc);
+
+    rc = zmq_disconnect (sc, endpoint);
+    assert (rc == 0);
     rc = zmq_unbind (sb, endpoint);
     assert (rc == 0);
 
+    rc = zmq_close (sc);
+    assert (rc == 0);
     rc = zmq_close (sb);
     assert (rc == 0);
 
+    /* Address wildcard, IPv6 enabled */
+    sb = zmq_socket (ctx, ZMQ_REP);
+    assert (sb);
+    sc = zmq_socket (ctx, ZMQ_REQ);
+    assert (sc);
+
+    rc = zmq_setsockopt (sb, ZMQ_IPV6, &ipv6, sizeof (int));
+    assert (rc == 0);
+    rc = zmq_setsockopt (sc, ZMQ_IPV6, &ipv6, sizeof (int));
+    assert (rc == 0);
+
+    rc = zmq_bind (sb, "tcp://*:5556");
+    assert (rc == 0);
+
+    endpoint_len = sizeof (endpoint);
+    memset(endpoint, 0, endpoint_len);
+    rc = zmq_getsockopt (sb, ZMQ_LAST_ENDPOINT, endpoint, &endpoint_len);
+    assert (rc == 0);
+
+    rc = zmq_connect (sc, endpoint);
+    assert (rc == 0);
+
+    bounce (sb, sc);
+
+    rc = zmq_disconnect (sc, endpoint);
+    assert (rc == 0);
+    rc = zmq_unbind (sb, endpoint);
+    assert (rc == 0);
+
+    rc = zmq_close (sc);
+    assert (rc == 0);
+    rc = zmq_close (sb);
+    assert (rc == 0);
+
+    /* Port wildcard, IPv4 address, IPv6 disabled */
+    sb = zmq_socket (ctx, ZMQ_REP);
+    assert (sb);
+    sc = zmq_socket (ctx, ZMQ_REQ);
+    assert (sc);
+
+    rc = zmq_bind (sb, "tcp://127.0.0.1:*");
+    assert (rc == 0);
+
+    endpoint_len = sizeof (endpoint);
+    memset(endpoint, 0, endpoint_len);
+    rc = zmq_getsockopt (sb, ZMQ_LAST_ENDPOINT, endpoint, &endpoint_len);
+    assert (rc == 0);
+
+    rc = zmq_connect (sc, endpoint);
+    assert (rc == 0);
+
+    bounce (sb, sc);
+
+    rc = zmq_disconnect (sc, endpoint);
+    assert (rc == 0);
+    rc = zmq_unbind (sb, endpoint);
+    assert (rc == 0);
+
+    rc = zmq_close (sc);
+    assert (rc == 0);
+    rc = zmq_close (sb);
+    assert (rc == 0);
+
+    /* Port wildcard, IPv4 address, IPv6 enabled */
+    sb = zmq_socket (ctx, ZMQ_REP);
+    assert (sb);
+    sc = zmq_socket (ctx, ZMQ_REQ);
+    assert (sc);
+
+    rc = zmq_setsockopt (sb, ZMQ_IPV6, &ipv6, sizeof (int));
+    assert (rc == 0);
+    rc = zmq_setsockopt (sc, ZMQ_IPV6, &ipv6, sizeof (int));
+    assert (rc == 0);
+
+    rc = zmq_bind (sb, "tcp://127.0.0.1:*");
+    assert (rc == 0);
+
+    endpoint_len = sizeof (endpoint);
+    memset(endpoint, 0, endpoint_len);
+    rc = zmq_getsockopt (sb, ZMQ_LAST_ENDPOINT, endpoint, &endpoint_len);
+    assert (rc == 0);
+
+    rc = zmq_connect (sc, endpoint);
+    assert (rc == 0);
+
+    bounce (sb, sc);
+
+    rc = zmq_disconnect (sc, endpoint);
+    assert (rc == 0);
+    rc = zmq_unbind (sb, endpoint);
+    assert (rc == 0);
+
+    rc = zmq_close (sc);
+    assert (rc == 0);
+    rc = zmq_close (sb);
+    assert (rc == 0);
+
+    if (ipv6) {
+        /* Port wildcard, IPv6 address, IPv6 enabled */
+        sb = zmq_socket (ctx, ZMQ_REP);
+        assert (sb);
+        sc = zmq_socket (ctx, ZMQ_REQ);
+        assert (sc);
+
+        rc = zmq_setsockopt (sb, ZMQ_IPV6, &ipv6, sizeof (int));
+        assert (rc == 0);
+        rc = zmq_setsockopt (sc, ZMQ_IPV6, &ipv6, sizeof (int));
+        assert (rc == 0);
+
+        rc = zmq_bind (sb, "tcp://[::1]:*");
+        assert (rc == 0);
+
+        endpoint_len = sizeof (endpoint);
+        memset(endpoint, 0, endpoint_len);
+        rc = zmq_getsockopt (sb, ZMQ_LAST_ENDPOINT, endpoint, &endpoint_len);
+        assert (rc == 0);
+
+        rc = zmq_connect (sc, endpoint);
+        assert (rc == 0);
+
+        bounce (sb, sc);
+
+        rc = zmq_disconnect (sc, endpoint);
+        assert (rc == 0);
+        rc = zmq_unbind (sb, endpoint);
+        assert (rc == 0);
+
+        rc = zmq_close (sc);
+        assert (rc == 0);
+        rc = zmq_close (sb);
+        assert (rc == 0);
+    }
+
+    /* No wildcard, IPv4 address, IPv6 disabled */
+    sb = zmq_socket (ctx, ZMQ_REP);
+    assert (sb);
+    sc = zmq_socket (ctx, ZMQ_REQ);
+    assert (sc);
+
+    rc = zmq_bind (sb, "tcp://127.0.0.1:5557");
+    assert (rc == 0);
+    rc = zmq_connect (sc, "tcp://127.0.0.1:5557");
+    assert (rc == 0);
+
+    bounce (sb, sc);
+
+    rc = zmq_disconnect (sc, "tcp://127.0.0.1:5557");
+    assert (rc == 0);
+    rc = zmq_unbind (sb, "tcp://127.0.0.1:5557");
+    assert (rc == 0);
+
+    rc = zmq_close (sc);
+    assert (rc == 0);
+    rc = zmq_close (sb);
+    assert (rc == 0);
+
+    /* No wildcard, IPv4 address, IPv6 enabled */
+    sb = zmq_socket (ctx, ZMQ_REP);
+    assert (sb);
+    sc = zmq_socket (ctx, ZMQ_REQ);
+    assert (sc);
+
+    rc = zmq_setsockopt (sb, ZMQ_IPV6, &ipv6, sizeof (int));
+    assert (rc == 0);
+    rc = zmq_setsockopt (sc, ZMQ_IPV6, &ipv6, sizeof (int));
+    assert (rc == 0);
+
+    rc = zmq_bind (sb, "tcp://127.0.0.1:5558");
+    assert (rc == 0);
+    rc = zmq_connect (sc, "tcp://127.0.0.1:5558");
+    assert (rc == 0);
+
+    bounce (sb, sc);
+
+    rc = zmq_disconnect (sc, "tcp://127.0.0.1:5558");
+    assert (rc == 0);
+    rc = zmq_unbind (sb, "tcp://127.0.0.1:5558");
+    assert (rc == 0);
+
+    rc = zmq_close (sc);
+    assert (rc == 0);
+    rc = zmq_close (sb);
+    assert (rc == 0);
+
+    if (ipv6) {
+        /* No wildcard, IPv6 address, IPv6 enabled */
+        sb = zmq_socket (ctx, ZMQ_REP);
+        assert (sb);
+        sc = zmq_socket (ctx, ZMQ_REQ);
+        assert (sc);
+
+        rc = zmq_setsockopt (sb, ZMQ_IPV6, &ipv6, sizeof (int));
+        assert (rc == 0);
+        rc = zmq_setsockopt (sc, ZMQ_IPV6, &ipv6, sizeof (int));
+        assert (rc == 0);
+
+        rc = zmq_bind (sb, "tcp://[::1]:5559");
+        assert (rc == 0);
+        rc = zmq_connect (sc, "tcp://[::1]:5559");
+        assert (rc == 0);
+
+        bounce (sb, sc);
+
+        rc = zmq_disconnect (sc, "tcp://[::1]:5559");
+        assert (rc == 0);
+        rc = zmq_unbind (sb, "tcp://[::1]:5559");
+        assert (rc == 0);
+
+        rc = zmq_close (sc);
+        assert (rc == 0);
+        rc = zmq_close (sb);
+        assert (rc == 0);
+    }
+
     rc = zmq_ctx_term (ctx);
     assert (rc == 0);