diff --git a/question/engine/bank.php b/question/engine/bank.php
index c239388d591..5f01a2ece02 100644
--- a/question/engine/bank.php
+++ b/question/engine/bank.php
@@ -264,7 +264,6 @@ abstract class question_bank {
      * @return question_definition loaded from the database.
      */
     public static function load_question($questionid, $allowshuffle = true) {
-        global $DB;
 
         if (self::$testmode) {
             // Evil, test code in production, but no way round it.
diff --git a/question/type/ddwtos/tests/helper.php b/question/type/ddwtos/tests/helper.php
index ade05700c5f..3ccd35bfd50 100644
--- a/question/type/ddwtos/tests/helper.php
+++ b/question/type/ddwtos/tests/helper.php
@@ -34,7 +34,7 @@ defined('MOODLE_INTERNAL') || die();
  */
 class qtype_ddwtos_test_helper extends question_test_helper {
     public function get_test_questions() {
-        return array('fox', 'maths', 'oddgroups');
+        return array('fox', 'maths', 'oddgroups', 'missingchoiceno');
     }
 
     /**
@@ -128,6 +128,31 @@ class qtype_ddwtos_test_helper extends question_test_helper {
         return $fromform;
     }
 
+    /**
+     * Get data required to save a drag-drop into text question where the author
+     * missed out one of the group numbers.
+     *
+     * @return stdClass data to create a ddwtos question.
+     */
+    public function get_ddwtos_question_form_data_missingchoiceno() {
+        $fromform = new stdClass();
+
+        $fromform->name = 'Drag-drop into text question with one index missing';
+        $fromform->questiontext = ['text' => 'The [[1]] sat on the [[3]].', 'format' => FORMAT_HTML];
+        $fromform->defaultmark = 1.0;
+        $fromform->generalfeedback = array('text' => 'The right answer is: "The cat sat on the mat."', 'format' => FORMAT_HTML);
+        $fromform->choices = array(
+                array('answer' => 'cat', 'choicegroup' => '1'),
+                array('answer' => '',    'choicegroup' => '1'),
+                array('answer' => 'mat', 'choicegroup' => '1'),
+        );
+        test_question_maker::set_standard_combined_feedback_form_data($fromform);
+        $fromform->shownumcorrect = 0;
+        $fromform->penalty = 0.3333333;
+
+        return $fromform;
+    }
+
     /**
      * @return qtype_ddwtos_question
      */
diff --git a/question/type/ddwtos/tests/questiontype_test.php b/question/type/ddwtos/tests/questiontype_test.php
index ded8ebef094..ca7f562f0bd 100644
--- a/question/type/ddwtos/tests/questiontype_test.php
+++ b/question/type/ddwtos/tests/questiontype_test.php
@@ -117,6 +117,31 @@ class qtype_ddwtos_test extends question_testcase {
         $this->assertTrue($this->qtype->can_analyse_responses());
     }
 
+    public function test_save_question() {
+        $this->resetAfterTest();
+
+        $syscontext = context_system::instance();
+        /** @var core_question_generator $generator */
+        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');
+        $category = $generator->create_question_category(['contextid' => $syscontext->id]);
+
+        $fromform = test_question_maker::get_question_form_data('ddwtos', 'missingchoiceno');
+        $fromform->category = $category->id . ',' . $syscontext->id;
+
+        $question = new stdClass();
+        $question->category = $category->id;
+        $question->qtype = 'ddwtos';
+        $question->createdby = 0;
+
+        $this->qtype->save_question($question, $fromform);
+        $q = question_bank::load_question($question->id);
+        // We just want to verify that this does not cause errors,
+        // but also verify some of the outcome.
+        $this->assertEquals('The [[1]] sat on the [[2]].', $q->questiontext);
+        $this->assertEquals([1 => 1, 2 => 1], $q->places);
+        $this->assertEquals([1 => 1, 2 => 2], $q->rightchoices);
+    }
+
     public function test_initialise_question_instance() {
         $qdata = $this->get_test_question_data();
 
diff --git a/question/type/gapselect/questiontypebase.php b/question/type/gapselect/questiontypebase.php
index de9f1493e74..86f4a3d5c14 100644
--- a/question/type/gapselect/questiontypebase.php
+++ b/question/type/gapselect/questiontypebase.php
@@ -49,7 +49,35 @@ abstract class qtype_gapselect_base extends question_type {
     public function save_question_options($question) {
         global $DB;
         $context = $question->context;
-        $result = new stdClass();
+
+        // This question type needs the choices to be consecutively numbered, but
+        // there is no reason why the question author should have done that,
+        // so renumber if necessary.
+        // Insert all the new answers.
+        $nonblankchoices = [];
+        $questiontext = $question->questiontext;
+        $newkey = 0;
+        foreach ($question->choices as $key => $choice) {
+            if (trim($choice['answer']) == '') {
+                continue;
+            }
+
+            $nonblankchoices[] = $choice;
+            if ($newkey != $key) {
+                // Safe to do this in this order, because we will always be replacing
+                // a bigger number with a smaller number that is not present.
+                // Numbers in the question text always one bigger than the array index.
+                $questiontext = str_replace('[[' . ($key + 1) . ']]', '[[' . ($newkey + 1) . ']]',
+                        $questiontext);
+            }
+            $newkey += 1;
+        }
+        $question->choices = $nonblankchoices;
+        if ($questiontext !== $question->questiontext) {
+            $DB->set_field('question', 'questiontext', $questiontext,
+                    ['id' => $question->id]);
+            $question->questiontext = $questiontext;
+        }
 
         $oldanswers = $DB->get_records('question_answers',
                 array('question' => $question->id), 'id ASC');
@@ -57,14 +85,12 @@ abstract class qtype_gapselect_base extends question_type {
         // Insert all the new answers.
         foreach ($question->choices as $key => $choice) {
 
-            if (trim($choice['answer']) == '') {
-                continue;
-            }
+            // Answer guaranteed to be non-blank. See above.
 
             $feedback = $this->choice_options_to_feedback($choice);
 
             if ($answer = array_shift($oldanswers)) {
-                $answer->answer = $choice['answer'];
+                $answer->answer = trim($choice['answer']);
                 $answer->feedback = $feedback;
                 $DB->update_record('question_answers', $answer);
 
diff --git a/question/type/gapselect/tests/helper.php b/question/type/gapselect/tests/helper.php
index ae809adc13f..5907cc122c8 100644
--- a/question/type/gapselect/tests/helper.php
+++ b/question/type/gapselect/tests/helper.php
@@ -33,10 +33,16 @@ defined('MOODLE_INTERNAL') || die();
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class qtype_gapselect_test_helper extends question_test_helper {
+
     public function get_test_questions() {
-        return array('fox', 'maths', 'currency', 'multilang');
+        return array('fox', 'maths', 'currency', 'multilang', 'missingchoiceno');
     }
 
+    /**
+     * Get data you would get by loading a typical select missing words question.
+     *
+     * @return stdClass as returned by question_bank::load_question_data for this qtype.
+     */
     public static function get_gapselect_question_data_fox() {
         global $USER;
 
@@ -81,6 +87,31 @@ class qtype_gapselect_test_helper extends question_test_helper {
         return $gapselect;
     }
 
+    /**
+     * Get data required to save a select missing words question where
+     * the author missed out one of the group numbers.
+     *
+     * @return stdClass data to create a gapselect question.
+     */
+    public function get_gapselect_question_form_data_missingchoiceno() {
+        $fromform = new stdClass();
+
+        $fromform->name = 'Select missing words question';
+        $fromform->questiontext = ['text' => 'The [[1]] sat on the [[3]].', 'format' => FORMAT_HTML];
+        $fromform->defaultmark = 1.0;
+        $fromform->generalfeedback = ['text' => 'The right answer is: "The cat sat on the mat."', 'format' => FORMAT_HTML];
+        $fromform->choices = [
+                ['answer' => 'cat', 'choicegroup' => '1'],
+                ['answer' => '',    'choicegroup' => '1'],
+                ['answer' => 'mat', 'choicegroup' => '1'],
+        ];
+        test_question_maker::set_standard_combined_feedback_form_data($fromform);
+        $fromform->shownumcorrect = 0;
+        $fromform->penalty = 0.3333333;
+
+        return $fromform;
+    }
+
     /**
      * Get an example gapselect question to use for testing. This examples has one of each item.
      * @return qtype_gapselect_question
diff --git a/question/type/gapselect/tests/questiontype_test.php b/question/type/gapselect/tests/questiontype_test.php
index dc076b07499..88ccadf28af 100644
--- a/question/type/gapselect/tests/questiontype_test.php
+++ b/question/type/gapselect/tests/questiontype_test.php
@@ -58,6 +58,31 @@ class qtype_gapselect_test extends question_testcase {
                 str_replace("\r\n", "\n", $xml));
     }
 
+    public function test_save_question() {
+        $this->resetAfterTest();
+
+        $syscontext = context_system::instance();
+        /** @var core_question_generator $generator */
+        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');
+        $category = $generator->create_question_category(['contextid' => $syscontext->id]);
+
+        $fromform = test_question_maker::get_question_form_data('gapselect', 'missingchoiceno');
+        $fromform->category = $category->id . ',' . $syscontext->id;
+
+        $question = new stdClass();
+        $question->category = $category->id;
+        $question->qtype = 'gapselect';
+        $question->createdby = 0;
+
+        $this->qtype->save_question($question, $fromform);
+        $q = question_bank::load_question($question->id);
+        // We just want to verify that this does not cause errors,
+        // but also verify some of the outcome.
+        $this->assertEquals('The [[1]] sat on the [[2]].', $q->questiontext);
+        $this->assertEquals([1 => 1, 2 => 1], $q->places);
+        $this->assertEquals([1 => 1, 2 => 2], $q->rightchoices);
+    }
+
     /**
      * Get some test question data.
      * @return object the data to construct a question like
diff --git a/question/type/questiontypebase.php b/question/type/questiontypebase.php
index d8f80435c78..2dccfcaff7b 100644
--- a/question/type/questiontypebase.php
+++ b/question/type/questiontypebase.php
@@ -323,9 +323,9 @@ class question_type {
      *       is accurate any more.)
      */
     public function save_question($question, $form) {
-        global $USER, $DB, $OUTPUT;
+        global $USER, $DB;
 
-        // The actuall update/insert done with multiple DB access, so we do it in a transaction.
+        // The actual update/insert done with multiple DB access, so we do it in a transaction.
         $transaction = $DB->start_delegated_transaction ();
 
         list($question->category) = explode(',', $form->category);