Negative test added for rescuing a paused vm

Added a negative test for rescuing
a paused vm.

Change-Id: I758283514a7bba99444bdf82f097d0a2b019e4d0
diff --git a/tempest/api/compute/servers/test_server_rescue.py b/tempest/api/compute/servers/test_server_rescue.py
index 13c2f74..b35b1b2 100644
--- a/tempest/api/compute/servers/test_server_rescue.py
+++ b/tempest/api/compute/servers/test_server_rescue.py
@@ -110,6 +110,11 @@
         self.assertEqual(202, resp.status)
         self.servers_client.wait_for_server_status(server_id, 'ACTIVE')
 
+    def _unpause(self, server_id):
+        resp, body = self.servers_client.unpause_server(server_id)
+        self.assertEqual(202, resp.status)
+        self.servers_client.wait_for_server_status(server_id, 'ACTIVE')
+
     @attr(type='smoke')
     def test_rescue_unrescue_instance(self):
         resp, body = self.servers_client.rescue_server(
@@ -121,6 +126,18 @@
         self.servers_client.wait_for_server_status(self.server_id, 'ACTIVE')
 
     @attr(type=['negative', 'gate'])
+    def test_rescue_paused_instance(self):
+        #Rescue a paused server
+        resp, body = self.servers_client.pause_server(
+            self.server_id)
+        self.addCleanup(self._unpause, self.server_id)
+        self.assertEqual(202, resp.status)
+        self.servers_client.wait_for_server_status(self.server_id, 'PAUSED')
+        self.assertRaises(exceptions.Duplicate,
+                          self.servers_client.rescue_server,
+                          self.server_id)
+
+    @attr(type=['negative', 'gate'])
     def test_rescued_vm_reboot(self):
         self.assertRaises(exceptions.Duplicate, self.servers_client.reboot,
                           self.rescue_id, 'HARD')