Fix inventory.get_hosts when hosts is a list.

lib/ansible/inventory/__init__.py

@@ -96,7 +96,9 @@ class Inventory(object):
         applied subsets.
         """
 
-        # process patterns        
+        # process patterns
+        if isinstance(pattern, list):
+            pattern = ';'.join(pattern)
         patterns = pattern.replace(";",":").split(":")
         positive_patterns = [ p for p in patterns if not p.startswith("!") ]
         negative_patterns = [ p for p in patterns if p.startswith("!") ]

test/TestInventory.py

@@ -238,3 +238,11 @@ class TestInventory(unittest.TestCase):
                         'group_names': ['norse'],
                         'inventory_hostname': 'thor',
                         'inventory_hostname_short': 'thor'}
+
+    def test_hosts_list(self):
+        """Test the case when playbook 'hosts' var is a list."""
+        inventory = self.script_inventory()
+        host_names = sorted(['thor', 'loki', 'odin'])       # Not sure if sorting is in the contract or not
+        actual_hosts = inventory.get_hosts(host_names)
+        actual_host_names = [host.name for host in actual_hosts]
+        assert host_names == actual_host_names