Fixed file client private attribute reference on SaltMakoTemplateLookup

Fixes #64280

Signed-off-by: Pedro Algarvio <palgarvio@vmware.com>

changelog/64280.fixed.md

@@ -0,0 +1 @@
+Fixed file client private attribute reference on `SaltMakoTemplateLookup`

salt/utils/mako.py

@@ -99,8 +99,10 @@ if HAS_MAKO:
                 )
 
         def destroy(self):
-            if self.client:
+            if self._file_client:
+                file_client = self._file_client
+                self._file_client = None
                 try:
-                    self.client.destroy()
+                    file_client.destroy()
                 except AttributeError:
                     pass

tests/pytests/unit/utils/test_mako.py

@@ -0,0 +1,28 @@
+import pytest
+
+from tests.support.mock import Mock, call, patch
+
+pytest.importorskip("mako")
+
+# This import needs to be after the above importorskip so that no ImportError
+# is raised if Mako is not installed
+from salt.utils.mako import SaltMakoTemplateLookup
+
+
+def test_mako_template_lookup(minion_opts):
+    """
+    The shudown method can be called without raising an exception when the
+    file_client does not have a destroy method
+    """
+    # Test SaltCacheLoader creating and destroying the file client created
+    file_client = Mock()
+    with patch("salt.fileclient.get_file_client", return_value=file_client):
+        loader = SaltMakoTemplateLookup(minion_opts)
+        assert loader._file_client is None
+        assert loader.file_client() is file_client
+        assert loader._file_client is file_client
+        try:
+            loader.destroy()
+        except AttributeError:
+            pytest.fail("Regression when calling SaltMakoTemplateLookup.destroy()")
+        assert file_client.mock_calls == [call.destroy()]