Replace urls in the welcome message.

openedx/features/course_experience/tests/views/test_welcome_message.py

@@ -67,6 +67,16 @@ class TestWelcomeMessageView(SharedModuleStoreTestCase):
         self.assertEqual(response.status_code, 200)
         self.assertContains(response, 'Second Update')
 
+    def test_replace_urls(self):
+        img_url = 'img.png'
+        create_course_update(self.course, self.user, "<img src='/static/{url}'>".format(url=img_url))
+        response = self.client.get(welcome_message_url(self.course))
+        self.assertContains(response, "/asset-v1:{org}+{course}+{run}+type@asset+block/img.png".format(
+            org=self.course.id.org,
+            course=self.course.id.course,
+            run=self.course.id.run
+        ))
+
     def test_empty_welcome_message(self):
         response = self.client.get(welcome_message_url(self.course))
         self.assertEqual(response.status_code, 204)

openedx/features/course_experience/views/welcome_message.py

@@ -45,4 +45,8 @@ class WelcomeMessageFragmentView(EdxFragmentView):
         # Return the course update with the most recent publish date
         info_block = getattr(info_module, '_xmodule', info_module)
         ordered_updates = info_block.ordered_updates()
-        return ordered_updates[0]['content'] if ordered_updates else None
+        content = None
+        if ordered_updates:
+            content = info_block.system.replace_urls(ordered_updates[0]['content'])
+
+        return content