Merge pull request #40631 from gtmanfred/grains

if grain is defined as None still convert in append

salt/states/grains.py

@@ -400,7 +400,11 @@ def append(name, value, convert=False,
            'result': True,
            'comment': ''}
     grain = __salt__['grains.get'](name, None)
-    if grain:
+
+    # Check if bool(grain) is False or if the grain is specified in the minions
+    # grains. Grains can be set to a None value by omitting a value in the
+    # definition.
+    if grain or name in __grains__:
         if isinstance(grain, list):
             if value in grain:
                 ret['comment'] = 'Value {1} is already in the list ' \
@@ -425,7 +429,7 @@ def append(name, value, convert=False,
                                      'added'.format(name, value)
                     ret['changes'] = {'added': value}
                     return ret
-                grain = [grain]
+                grain = [] if grain is None else [grain]
                 grain.append(value)
                 __salt__['grains.setval'](name, grain)
                 ret['comment'] = 'Value {1} was added to grain {0}'\

tests/unit/states/grains_test.py

@@ -828,6 +828,23 @@ class GrainsTestCase(TestCase):
             grains.__grains__,
             {'a': 'aval'})
 
+    def test_append_convert_to_list_empty(self):
+        # Append to an existing list
+        self.setGrains({'foo': None})
+        ret = grains.append(
+            name='foo',
+            value='baz',
+            convert=True)
+        self.assertEqual(ret['result'], True)
+        self.assertEqual(ret['comment'], 'Value baz was added to grain foo')
+        self.assertEqual(ret['changes'], {'added': 'baz'})
+        self.assertEqual(
+            grains.__grains__,
+            {'foo': ['baz']})
+        self.assertGrainFileContent("foo:\n"
+                                  + "- baz\n"
+        )
+
     # 'list_present' function tests: 7
 
     def test_list_present(self):