Fix when checking in mongo store, has_course with a split course key returns False.

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

@@ -1118,6 +1118,11 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
         otherwise, do a case sensitive search
         """
         assert isinstance(course_key, CourseKey)
+
+        if not course_key.deprecated:  # split course_key
+            # The supplied CourseKey is of the wrong type, so it can't possibly be stored in this modulestore.
+            return False
+
         if isinstance(course_key, LibraryLocator):
             return None  # Libraries require split mongo
         course_key = self.fill_in_run(course_key)

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

@@ -300,6 +300,14 @@ class TestMongoModuleStore(TestMongoModuleStoreBase):
         with self.assertRaises(ItemNotFoundError):
             self.draft_store.get_course(course_key)
 
+    def test_has_mongo_course_with_split_course_key(self):
+        """
+        Test `has course` using split course key would return False.
+        """
+        course_key = CourseKey.from_string('course-v1:edX+simple+2012_Fall')
+
+        self.assertFalse(self.draft_store.has_course(course_key))
+
     def test_has_course_with_library(self):
         """
         Test that has_course() returns False when called with a LibraryLocator.