Fixes for course import-export:

* Updated XBlock hash - new version forces exposes force_dirty method on fields
* Includes Scope.children fields into xml_importer._update_module_location so that they are updated as well.
* Tests for mutable fields xml_importer._update_module_location with mutable fields and children

common/lib/xmodule/xmodule/modulestore/tests/test_xml_importer.py

@@ -2,14 +2,15 @@
 Tests for XML importer.
 """
 import mock
+from opaque_keys.edx.locator import BlockUsageLocator, CourseLocator
 from xblock.core import XBlock
-from xblock.fields import String, Scope, ScopeIds
+from xblock.fields import String, Scope, ScopeIds, List
 from xblock.runtime import Runtime, KvsFieldData, DictKeyValueStore
 from xmodule.x_module import XModuleMixin
 from opaque_keys.edx.locations import Location
 from xmodule.modulestore import ModuleStoreEnum
 from xmodule.modulestore.inheritance import InheritanceMixin
-from xmodule.modulestore.xml_importer import _import_module_and_update_references
+from xmodule.modulestore.xml_importer import _import_module_and_update_references, _update_module_location
 from xmodule.modulestore.tests.mongo_connection import MONGO_PORT_NUM, MONGO_HOST
 from opaque_keys.edx.locations import SlashSeparatedCourseKey
 from xmodule.tests import DATA_DIR
@@ -229,3 +230,90 @@ class RemapNamespaceTest(ModuleStoreNoSettings):
         self.assertNotIn(
             'graded', new_version.get_explicitly_set_fields_by_scope(scope=Scope.settings)
         )
+
+
+class StubXBlockWithMutableFields(StubXBlock):
+    """
+    Stub XBlock used for testing mutable fields and children
+    """
+    has_children = True
+
+    test_mutable_content_field = List(
+        help="A mutable content field that will be explicitly set",
+        scope=Scope.content,
+    )
+
+    test_mutable_settings_field = List(
+        help="A mutable settings field that will be explicitly set",
+        scope=Scope.settings,
+    )
+
+
+class UpdateLocationTest(ModuleStoreNoSettings):
+    """
+    Test that updating location preserves "is_set_on" status on fields
+    """
+    CONTENT_FIELDS = ['test_content_field', 'test_mutable_content_field']
+    SETTINGS_FIELDS = ['test_settings_field', 'test_mutable_settings_field']
+    CHILDREN_FIELDS = ['children']
+
+    def setUp(self):
+        """
+        Create a stub XBlock backed by in-memory storage.
+        """
+        self.runtime = mock.MagicMock(Runtime)
+        self.field_data = KvsFieldData(kvs=DictKeyValueStore())
+        self.scope_ids = ScopeIds('Bob', 'mutablestubxblock', '123', 'import')
+        self.xblock = StubXBlockWithMutableFields(self.runtime, self.field_data, self.scope_ids)
+
+        self.fake_children_locations = [
+            BlockUsageLocator(CourseLocator('org', 'course', 'run'), 'mutablestubxblock', 'child1'),
+            BlockUsageLocator(CourseLocator('org', 'course', 'run'), 'mutablestubxblock', 'child2'),
+        ]
+
+        super(UpdateLocationTest, self).setUp()
+
+    def _check_explicitly_set(self, block, scope, expected_explicitly_set_fields, should_be_set=False):
+        """ Gets fields that are explicitly set on block and checks if they are marked as explicitly set or not """
+        actual_explicitly_set_fields = block.get_explicitly_set_fields_by_scope(scope=scope)
+        assertion = self.assertIn if should_be_set else self.assertNotIn
+        for field in expected_explicitly_set_fields:
+            assertion(field, actual_explicitly_set_fields)
+
+    def test_update_locations_native_xblock(self):
+        """ Update locations updates location and keeps values and "is_set_on" status """
+        # Set the XBlock's location
+        self.xblock.location = Location("org", "import", "run", "category", "stubxblock")
+
+        # Explicitly set the content, settings and children fields
+        self.xblock.test_content_field = 'Explicitly set'
+        self.xblock.test_settings_field = 'Explicitly set'
+        self.xblock.test_mutable_content_field = [1, 2, 3]
+        self.xblock.test_mutable_settings_field = ["a", "s", "d"]
+        self.xblock.children = self.fake_children_locations  # pylint:disable=attribute-defined-outside-init
+        self.xblock.save()
+
+        # Update location
+        target_location = self.xblock.location.replace(revision='draft')
+        _update_module_location(self.xblock, target_location)
+        new_version = self.xblock  # _update_module_location updates in-place
+
+        # Check the XBlock's location
+        self.assertEqual(new_version.location, target_location)
+
+        # Check the values of the fields.
+        # The content, settings and children fields should be preserved
+        self.assertEqual(new_version.test_content_field, 'Explicitly set')
+        self.assertEqual(new_version.test_settings_field, 'Explicitly set')
+        self.assertEqual(new_version.test_mutable_content_field, [1, 2, 3])
+        self.assertEqual(new_version.test_mutable_settings_field, ["a", "s", "d"])
+        self.assertEqual(new_version.children, self.fake_children_locations)
+
+        # Expect that these fields are marked explicitly set
+        self._check_explicitly_set(new_version, Scope.content, self.CONTENT_FIELDS, should_be_set=True)
+        self._check_explicitly_set(new_version, Scope.settings, self.SETTINGS_FIELDS, should_be_set=True)
+        self._check_explicitly_set(new_version, Scope.children, self.CHILDREN_FIELDS, should_be_set=True)
+
+        # Expect these fields pass "is_set_on" test
+        for field in self.CONTENT_FIELDS + self.SETTINGS_FIELDS + self.CHILDREN_FIELDS:
+            self.assertTrue(new_version.fields[field].is_set_on(new_version))

common/lib/xmodule/xmodule/modulestore/xml_importer.py

@@ -1154,7 +1154,8 @@ def _update_module_location(module, new_location):
     else:
         rekey_fields = (
             module.get_explicitly_set_fields_by_scope(Scope.content).keys() +
-            module.get_explicitly_set_fields_by_scope(Scope.settings).keys()
+            module.get_explicitly_set_fields_by_scope(Scope.settings).keys() +
+            module.get_explicitly_set_fields_by_scope(Scope.children).keys()
         )
 
     module.location = new_location

lms/djangoapps/ccx/tests/test_views.py

@@ -492,10 +492,13 @@ class TestCCXGrades(ModuleStoreTestCase, LoginEnrollmentTestCase):
         # sure if there's a way to poke the test harness to do so.  So, we'll
         # just inject the override field storage in this brute force manner.
         OverrideFieldData.provider_classes = None
+        # pylint: disable=protected-access
         for block in iter_blocks(course):
-            block._field_data = OverrideFieldData.wrap(   # pylint: disable=protected-access
-                coach, block._field_data)   # pylint: disable=protected-access
-            block._field_data_cache = {'tabs': [], 'discussion_topics': []}  # pylint: disable=protected-access
+            block._field_data = OverrideFieldData.wrap(coach, block._field_data)
+            new_cache = {'tabs': [], 'discussion_topics': []}
+            if 'grading_policy' in block._field_data_cache:
+                new_cache['grading_policy'] = block._field_data_cache['grading_policy']
+            block._field_data_cache = new_cache
 
         def cleanup_provider_classes():
             """

requirements/edx/github.txt

@@ -27,7 +27,7 @@ git+https://github.com/mfogel/django-settings-context-processor.git@b758c3930862
 git+https://github.com/pmitros/pyfs.git@96e1922348bfe6d99201b9512a9ed946c87b7e0b
 
 # Our libraries:
--e git+https://github.com/edx/XBlock.git@aed464a0e2f7478e93157150ac04133a745f5f46#egg=XBlock
+-e git+https://github.com/edx/XBlock.git@1934a2978cdd3e2414486c74b76e3040ff1fb138#egg=XBlock
 -e git+https://github.com/edx/codejail.git@6b17c33a89bef0ac510926b1d7fea2748b73aadd#egg=codejail
 -e git+https://github.com/edx/js-test-tool.git@v0.1.6#egg=js_test_tool
 -e git+https://github.com/edx/event-tracking.git@0.1.0#egg=event-tracking