Require markdown to be explicitly set

cms/djangoapps/contentstore/views/component.py

@@ -142,11 +142,10 @@ def edit_unit(request, location):
     for category in COMPONENT_TYPES:
         component_class = XModuleDescriptor.load_class(category)
         # add the default template
-        has_markdown = hasattr(component_class, 'markdown') and component_class.markdown is not None
         component_templates[category].append((
             component_class.display_name.default or 'Blank',
             category,
-            has_markdown,
+            False,  # No defaults have markdown (hardcoded current default)
             None  # no boilerplate for overrides
         ))
         # add boilerplates
@@ -175,7 +174,7 @@ def edit_unit(request, location):
                     component_templates['advanced'].append((
                         component_class.display_name.default or category,
                         category,
-                        hasattr(component_class, 'markdown') and component_class.markdown is not None,
+                        False,
                         None  # don't override default data
                         ))
                 except PluginMissingError:

common/lib/xmodule/xmodule/capa_module.py

@@ -146,7 +146,7 @@ class CapaFields(object):
         values={"min": 0, "step": .1},
         scope=Scope.settings
     )
-    markdown = String(help="Markdown source of this module", default="", scope=Scope.settings)
+    markdown = String(help="Markdown source of this module", default=None, scope=Scope.settings)
     source_code = String(
         help="Source code for LaTeX and Word problems. This feature is not well-supported.",
         scope=Scope.settings