[1.7.x] Added missing logic to TimeField.deconstruct().

If auto_now or auto_now_add was used then the serialized
field in the migration contained unnecessary `editable` and
`blank` arguments.

Backport of 74325339327e5b8a2480aee7f482bc71f73c71f9 from master.

2 files changed, 20 insertions, 0 deletions

diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py
index 1971882e22..824200aba3 100644
--- a/django/db/models/fields/__init__.py
+++ b/django/db/models/fields/__init__.py
@@ -1916,6 +1916,9 @@ class TimeField(Field):
             kwargs["auto_now"] = self.auto_now
         if self.auto_now_add is not False:
             kwargs["auto_now_add"] = self.auto_now_add
+        if self.auto_now or self.auto_now_add:
+            del kwargs['blank']
+            del kwargs['editable']
         return name, path, args, kwargs
 
     def get_internal_type(self):
diff --git a/tests/field_deconstruction/tests.py b/tests/field_deconstruction/tests.py
index 9a330b2998..cf699aeecd 100644
--- a/tests/field_deconstruction/tests.py
+++ b/tests/field_deconstruction/tests.py
@@ -336,6 +336,23 @@ class FieldDeconstructionTests(TestCase):
         self.assertEqual(args, [])
         self.assertEqual(kwargs, {})
 
+    def test_time_field(self):
+        field = models.TimeField()
+        name, path, args, kwargs = field.deconstruct()
+        self.assertEqual(path, "django.db.models.TimeField")
+        self.assertEqual(args, [])
+        self.assertEqual(kwargs, {})
+
+        field = models.TimeField(auto_now=True)
+        name, path, args, kwargs = field.deconstruct()
+        self.assertEqual(args, [])
+        self.assertEqual(kwargs, {'auto_now': True})
+
+        field = models.TimeField(auto_now_add=True)
+        name, path, args, kwargs = field.deconstruct()
+        self.assertEqual(args, [])
+        self.assertEqual(kwargs, {'auto_now_add': True})
+
     def test_url_field(self):
         field = models.URLField()
         name, path, args, kwargs = field.deconstruct()