Prevent connect a node to himself

Fix https://github.com/GNS3/gns3-gui/issues/1553

tests/controller/test_link.py

@@ -131,6 +131,22 @@ def test_add_node_cloud_to_cloud(async_run, project, compute):
         async_run(link.add_node(node2, 0, 4))
 
 
+def test_add_node_same_node(async_run, project, compute):
+    """
+    Connection to the same node is not allowed
+    """
+    node1 = Node(project, compute, "node1", node_type="qemu")
+    node1._ports = [EthernetPort("E0", 0, 0, 4), EthernetPort("E1", 0, 0, 5)]
+
+    link = Link(project)
+    link.create = AsyncioMagicMock()
+    link._project.controller.notification.emit = MagicMock()
+
+    async_run(link.add_node(node1, 0, 4))
+    with pytest.raises(aiohttp.web.HTTPConflict):
+        async_run(link.add_node(node1, 0, 5))
+
+
 def test_add_node_serial_to_ethernet(async_run, project, compute):
     """
     Serial to ethernet connection is not allowed

tests/controller/test_udp_link.py

@@ -187,10 +187,15 @@ def test_capture(async_run, project):
 def test_read_pcap_from_source(project, async_run):
     compute1 = MagicMock()
 
+    node_vpcs = Node(project, compute1, "V1", node_type="vpcs")
+    node_vpcs._ports = [EthernetPort("E0", 0, 0, 4)]
+    node_iou = Node(project, compute1, "I1", node_type="iou")
+    node_iou._ports = [EthernetPort("E0", 0, 3, 1)]
+
     link = UDPLink(project)
     link.create = AsyncioMagicMock()
-    async_run(link.add_node(compute1, 0, 4))
-    async_run(link.add_node(compute1, 3, 1))
+    async_run(link.add_node(node_vpcs, 0, 4))
+    async_run(link.add_node(node_iou, 3, 1))
 
     capture = async_run(link.start_capture())
     assert link._capture_node is not None