Fixed Course handouts rejects deletion of all text

cms/static/coffee/spec/views/course_info_spec.coffee

@@ -232,6 +232,20 @@ define ["js/views/course_info_handout", "js/views/course_info_update", "js/model
 
                 @handoutsEdit.render()
 
+            it "saves <ol></ol> when content left empty", ->
+                requests = AjaxHelpers["requests"](this)
+
+                # Enter empty string in the handouts section, verifying that the model
+                # is saved with '<ol></ol>' instead of the empty string
+                @handoutsEdit.$el.find('.edit-button').click()
+                spyOn(@handoutsEdit.$codeMirror, 'getValue').and.returnValue('')
+                spyOn(@model, "save").and.callThrough()
+                @handoutsEdit.$el.find('.save-button').click()
+                expect(@model.save).toHaveBeenCalled()
+
+                contentSaved = JSON.parse(requests[requests.length - 1].requestBody).data
+                expect(contentSaved).toEqual('<ol></ol>')
+
             it "does not rewrite links on save", ->
                 requests = AjaxHelpers["requests"](this)
 

cms/static/js/views/course_info_handout.js

@@ -50,10 +50,14 @@ define(['js/views/baseview', 'codemirror', 'common/js/components/views/feedback_
             },
 
             onSave: function(event) {
+                var handoutsContent = this.$codeMirror.getValue();
                 $('#handout_error').removeClass('is-shown');
                 $('.save-button').removeClass('is-disabled').attr('aria-disabled', false);
                 if ($('.CodeMirror-lines').find('.cm-error').length == 0) {
-                    this.model.set('data', this.$codeMirror.getValue());
+                    if (handoutsContent === '') {
+                        handoutsContent = '<ol></ol>';
+                    }
+                    this.model.set('data', handoutsContent);
                     var saving = new NotificationView.Mini({
                         title: gettext('Saving')
                     });