Fix STUD-1311 (Don't overwrite published content w/ draft content accidentally)

cms/djangoapps/contentstore/views/item.py

@@ -112,7 +112,8 @@ def xblock_handler(request, tag=None, package_id=None, branch=None, version_guid
             accept_header = request.META.get('HTTP_ACCEPT', 'application/json')
 
             if 'application/x-fragment+json' in accept_header:
-                component = modulestore().get_item(old_location)
+                store = get_modulestore(old_location)
+                component = store.get_item(old_location)
 
                 # Wrap the generated fragment in the xmodule_editor div so that the javascript
                 # can bind to it correctly
@@ -127,7 +128,7 @@ def xblock_handler(request, tag=None, package_id=None, branch=None, version_guid
                     log.debug("Unable to render studio_view for %r", component, exc_info=True)
                     editor_fragment = Fragment(render_to_string('html_error.html', {'message': str(exc)}))
 
-                modulestore().save_xmodule(component)
+                store.save_xmodule(component)
 
                 preview_fragment = get_preview_fragment(request, component)
 

common/lib/xmodule/xmodule/modulestore/mongo/draft.py

@@ -108,6 +108,20 @@ class DraftModuleStore(MongoModuleStore):
             raise InvalidVersionError(location)
         return super(DraftModuleStore, self).create_xmodule(draft_loc, definition_data, metadata, system)
 
+    def save_xmodule(self, xmodule):
+        """
+        Save the given xmodule (will either create or update based on whether id already exists).
+        Pulls out the data definition v metadata v children locally but saves it all.
+
+        :param xmodule:
+        """
+        orig_location = xmodule.location
+
+        xmodule.location = as_draft(orig_location)
+        try:
+            super(DraftModuleStore, self).save_xmodule(xmodule)
+        finally:
+            xmodule.location = orig_location
 
     def get_items(self, location, course_id=None, depth=0):
         """