Properly handle group/host_var files with dots in them

Fixes #12245

lib/ansible/vars/__init__.py

@@ -317,9 +317,9 @@ class VariableManager:
         else:
             file_name, ext = os.path.splitext(path)
             data = None
-            if not ext:
+            if not ext or ext not in C.YAML_FILENAME_EXTENSIONS:
-                for ext in C.YAML_FILENAME_EXTENSIONS:
+                for test_ext in C.YAML_FILENAME_EXTENSIONS:
-                    new_path = path + ext
+                    new_path = path + test_ext
                     if loader.path_exists(new_path):
                         data = loader.load_from_file(new_path)
                         break

test/units/vars/test_variable_manager.py

@@ -75,6 +75,9 @@ class TestVariableManager(unittest.TestCase):
                foo: bam
                baa: bat
             """,
+            "host_vars/host.name.yml": """
+               host_with_dots: true
+            """,
         })
 
         v = VariableManager()
@@ -92,6 +95,9 @@ class TestVariableManager(unittest.TestCase):
         self.assertEqual(v.get_vars(loader=fake_loader, host=mock_host, use_cache=False).get("foo"), "bam")
         self.assertEqual(v.get_vars(loader=fake_loader, host=mock_host, use_cache=False).get("baa"), "bat")
 
+        v.add_host_vars_file("host_vars/host.name", loader=fake_loader)
+        self.assertEqual(v._host_vars_files["host.name"], [dict(host_with_dots=True)])
+
     def test_variable_manager_group_vars_file(self):
         fake_loader = DictDataLoader({
             "group_vars/all.yml": """
@@ -102,7 +108,10 @@ class TestVariableManager(unittest.TestCase):
             """,
             "other_path/group_vars/somegroup.yml": """
                baa: bat
-            """
+            """,
+            "group_vars/some.group.yml": """
+               group_with_dots: true
+            """,
         })
 
         v = VariableManager()
@@ -128,6 +137,9 @@ class TestVariableManager(unittest.TestCase):
         self.assertEqual(vars.get("foo"), "bar")
         self.assertEqual(vars.get("baa"), "bat")
 
+        v.add_group_vars_file("group_vars/some.group", loader=fake_loader)
+        self.assertEqual(v._group_vars_files["some.group"], [dict(group_with_dots=True)])
+
     def test_variable_manager_play_vars(self):
         fake_loader = DictDataLoader({})