Magic to get around a core Drupal problem.

includes/ingest.form.inc

@@ -706,7 +706,11 @@ function islandora_ingest_form_ingest_button(array &$form_state) {
   $validate_callback = $form_id . '_validate';
   $validate = function_exists($validate_callback) ? array($validate_callback) : NULL;
   $submit_callback = $form_id . '_submit';
-  $submit = function_exists($submit_callback) ? array($submit_callback, 'islandora_ingest_form_submit') : array('islandora_ingest_form_submit');
+  $submit = function_exists($submit_callback) ? array(
+    $submit_callback,
+    'islandora_ingest_form_pre_submit',
+    'islandora_ingest_form_submit',
+  ) : array('islandora_ingest_form_pre_submit', 'islandora_ingest_form_submit');
   return array(
     '#type' => 'submit',
     '#name' => 'ingest',

islandora.module

@@ -1913,3 +1913,19 @@ function islandora_find_package($package_name) {
   }
   return $found && user_access('administer site configuration');
 }
+
+/**
+ * Helper function for ingest steps and batches.
+ *
+ * When batches within batches are triggered within ingest steps
+ * the submit handler becomes out of scope. When it becomes time to execute the
+ * submit the function cannot be found and fails. This pre-submit is to
+ * get around this problem.
+ *
+ * @see https://www.drupal.org/node/2300367
+ *
+ * @see https://www.drupal.org/node/1300928
+ */
+function islandora_ingest_form_pre_submit($form, &$form_state) {
+  module_load_include('inc', 'islandora', 'includes/ingest.form');
+}