diff --git a/admin/tool/uploadcourse/classes/helper.php b/admin/tool/uploadcourse/classes/helper.php
index 917e265ee3c..72444e1b144 100644
--- a/admin/tool/uploadcourse/classes/helper.php
+++ b/admin/tool/uploadcourse/classes/helper.php
@@ -60,10 +60,10 @@ class tool_uploadcourse_helper {
      *
      * @param array|object $data course data.
      * @param string $templateshortname template of shortname.
-     * @return null|string shortname based on the template.
+     * @return null|string shortname based on the template, or null when an error occured.
      */
     public static function generate_shortname($data, $templateshortname) {
-        if (is_null($templateshortname)) {
+        if (empty($templateshortname) && !is_numeric($templateshortname)) {
             return null;
         }
         if (strpos($templateshortname, '%') === false) {
@@ -71,30 +71,32 @@ class tool_uploadcourse_helper {
         }
 
         $course = (object) $data;
-        $shortname  = isset($course->shortname) ? $course->shortname  : '';
         $fullname   = isset($course->fullname) ? $course->fullname : '';
         $idnumber   = isset($course->idnumber) ? $course->idnumber  : '';
 
-        $callback = partial(array('tool_uploadcourse_helper', 'generate_shortname_callback'), $shortname, $fullname, $idnumber);
+        $callback = partial(array('tool_uploadcourse_helper', 'generate_shortname_callback'), $fullname, $idnumber);
         $result = preg_replace_callback('/(?<!%)%([+~-])?(\d)*([fi])/', $callback, $templateshortname);
 
         if (!is_null($result)) {
             $result = clean_param($result, PARAM_TEXT);
         }
 
+        if (empty($result) && !is_numeric($result)) {
+            $result = null;
+        }
+
         return $result;
     }
 
     /**
      * Callback used when generating a shortname based on a template.
      *
-     * @param string $shortname short name.
      * @param string $fullname full name.
      * @param string $idnumber ID number.
      * @param array $block result from preg_replace_callback.
      * @return string
      */
-    public static function generate_shortname_callback($shortname, $fullname, $idnumber, $block) {
+    public static function generate_shortname_callback($fullname, $idnumber, $block) {
         switch ($block[3]) {
             case 'f':
                 $repl = $fullname;
diff --git a/admin/tool/uploadcourse/tests/course_test.php b/admin/tool/uploadcourse/tests/course_test.php
index 793e18467ed..f04a2eae104 100644
--- a/admin/tool/uploadcourse/tests/course_test.php
+++ b/admin/tool/uploadcourse/tests/course_test.php
@@ -56,6 +56,28 @@ class tool_uploadcourse_course_testcase extends advanced_testcase {
         $co->proceed();
     }
 
+    public function test_proceed_when_already_started() {
+        $this->resetAfterTest(true);
+        $mode = tool_uploadcourse_processor::MODE_CREATE_NEW;
+        $updatemode = tool_uploadcourse_processor::UPDATE_NOTHING;
+        $data = array('shortname' => 'test', 'fullname' => 'New course', 'summary' => 'New', 'category' => 1);
+        $co = new tool_uploadcourse_course($mode, $updatemode, $data);
+        $this->assertTrue($co->prepare());
+        $co->proceed();
+        $this->setExpectedException('coding_exception');
+        $co->proceed();
+    }
+
+    public function test_invalid_shortname() {
+        $this->resetAfterTest(true);
+        $mode = tool_uploadcourse_processor::MODE_CREATE_NEW;
+        $updatemode = tool_uploadcourse_processor::UPDATE_NOTHING;
+        $data = array('shortname' => '<invalid>', 'fullname' => 'New course', 'summary' => 'New', 'category' => 1);
+        $co = new tool_uploadcourse_course($mode, $updatemode, $data);
+        $this->assertFalse($co->prepare());
+        $this->assertArrayHasKey('invalidshortname', $co->get_errors());
+    }
+
     public function test_create() {
         global $DB;
         $this->resetAfterTest(true);
@@ -497,6 +519,7 @@ class tool_uploadcourse_course_testcase extends advanced_testcase {
         $this->resetAfterTest(true);
 
         $c1 = $this->getDataGenerator()->create_course(array('shortname' => 'c1'));
+        $c2 = $this->getDataGenerator()->create_course(array('shortname' => 'c2'));
 
         // Cannot rename when creating.
         $mode = tool_uploadcourse_processor::MODE_CREATE_NEW;
@@ -566,6 +589,24 @@ class tool_uploadcourse_course_testcase extends advanced_testcase {
         $this->assertEquals('c1', $DB->get_field_select('course', 'shortname', 'id = :id', array('id' => $c1->id)));
         $this->assertEquals('New summary!', $DB->get_field_select('course', 'summary', 'id = :id', array('id' => $c1->id)));
         $this->assertEquals('Another fullname!', $DB->get_field_select('course', 'fullname', 'id = :id', array('id' => $c1->id)));
+
+        // Renaming with invalid shortname.
+        $mode = tool_uploadcourse_processor::MODE_CREATE_OR_UPDATE;
+        $updatemode = tool_uploadcourse_processor::UPDATE_ALL_WITH_DATA_ONLY;
+        $importoptions = array('canrename' => true);
+        $data = array('shortname' => 'c1', 'rename' => '<span>invalid</span>');
+        $co = new tool_uploadcourse_course($mode, $updatemode, $data, array(), $importoptions);
+        $this->assertFalse($co->prepare());
+        $this->assertArrayHasKey('invalidshortname', $co->get_errors());
+
+        // Renaming with invalid shortname.
+        $mode = tool_uploadcourse_processor::MODE_CREATE_OR_UPDATE;
+        $updatemode = tool_uploadcourse_processor::UPDATE_ALL_WITH_DATA_ONLY;
+        $importoptions = array('canrename' => true);
+        $data = array('shortname' => 'c1', 'rename' => 'c2');
+        $co = new tool_uploadcourse_course($mode, $updatemode, $data, array(), $importoptions);
+        $this->assertFalse($co->prepare());
+        $this->assertArrayHasKey('cannotrenameshortnamealreadyinuse', $co->get_errors());
     }
 
     public function test_restore_course() {
@@ -779,7 +820,7 @@ class tool_uploadcourse_course_testcase extends advanced_testcase {
     public function test_idnumber_problems() {
         $this->resetAfterTest(true);
 
-        $c1 = $this->getDataGenerator()->create_course(array('idnumber' => 'Taken'));
+        $c1 = $this->getDataGenerator()->create_course(array('shortname' => 'sntaken', 'idnumber' => 'taken'));
         $c2 = $this->getDataGenerator()->create_course();
 
         // Create with existing ID number.
@@ -799,6 +840,84 @@ class tool_uploadcourse_course_testcase extends advanced_testcase {
         $co = new tool_uploadcourse_course($mode, $updatemode, $data, array(), $importoptions);
         $this->assertFalse($co->prepare());
         $this->assertArrayHasKey('cannotrenameidnumberconflict', $co->get_errors());
+
+        // Incrementing shortname increments idnumber.
+        $mode = tool_uploadcourse_processor::MODE_CREATE_ALL;
+        $updatemode = tool_uploadcourse_processor::UPDATE_NOTHING;
+        $data = array('shortname' => $c1->shortname, 'idnumber' => $c1->idnumber, 'summary' => 'S', 'fullname' => 'F',
+            'category' => 1);
+        $co = new tool_uploadcourse_course($mode, $updatemode, $data, array(), array());
+        $this->assertTrue($co->prepare());
+        $this->assertArrayHasKey('courseshortnameincremented', $co->get_statuses());
+        $this->assertArrayHasKey('courseidnumberincremented', $co->get_statuses());
+        $data = $co->get_data();
+        $this->assertEquals('sntaken_2', $data['shortname']);
+        $this->assertEquals('taken_2', $data['idnumber']);
+
+        // Incrementing shortname increments idnumber unless available.
+        $mode = tool_uploadcourse_processor::MODE_CREATE_ALL;
+        $updatemode = tool_uploadcourse_processor::UPDATE_NOTHING;
+        $data = array('shortname' => $c1->shortname, 'idnumber' => 'nottaken', 'summary' => 'S', 'fullname' => 'F',
+            'category' => 1);
+        $co = new tool_uploadcourse_course($mode, $updatemode, $data, array(), array());
+        $this->assertTrue($co->prepare());
+        $this->assertArrayHasKey('courseshortnameincremented', $co->get_statuses());
+        $this->assertArrayNotHasKey('courseidnumberincremented', $co->get_statuses());
+        $data = $co->get_data();
+        $this->assertEquals('sntaken_2', $data['shortname']);
+        $this->assertEquals('nottaken', $data['idnumber']);
+    }
+
+    public function test_generate_shortname() {
+        $this->resetAfterTest(true);
+
+        $c1 = $this->getDataGenerator()->create_course(array('shortname' => 'taken'));
+
+        // Generate a shortname.
+        $mode = tool_uploadcourse_processor::MODE_CREATE_NEW;
+        $updatemode = tool_uploadcourse_processor::UPDATE_NOTHING;
+        $data = array('summary' => 'summary', 'fullname' => 'FN', 'category' => '1', 'idnumber' => 'IDN');
+        $importoptions = array('shortnametemplate' => '%i');
+        $co = new tool_uploadcourse_course($mode, $updatemode, $data, array(), $importoptions);
+        $this->assertTrue($co->prepare());
+        $this->assertArrayHasKey('courseshortnamegenerated', $co->get_statuses());
+
+        // Generate a shortname without a template.
+        $mode = tool_uploadcourse_processor::MODE_CREATE_NEW;
+        $updatemode = tool_uploadcourse_processor::UPDATE_NOTHING;
+        $data = array('summary' => 'summary', 'fullname' => 'FN', 'category' => '1');
+        $co = new tool_uploadcourse_course($mode, $updatemode, $data, array(), array());
+        $this->assertFalse($co->prepare());
+        $this->assertArrayHasKey('missingshortnamenotemplate', $co->get_errors());
+
+        // Generate a shortname in update mode.
+        $mode = tool_uploadcourse_processor::MODE_UPDATE_ONLY;
+        $updatemode = tool_uploadcourse_processor::UPDATE_ALL_WITH_DATA_ONLY;
+        $data = array('summary' => 'summary', 'fullname' => 'FN', 'category' => '1');
+        $importoptions = array('shortnametemplate' => '%f');
+        $co = new tool_uploadcourse_course($mode, $updatemode, $data, array(), $importoptions);
+        $this->assertFalse($co->prepare());
+        // Commented because we never get here as the course without shortname does not exist.
+        // $this->assertArrayHasKey('cannotgenerateshortnameupdatemode', $co->get_errors());
+
+        // Generate a shortname to a course that already exists.
+        $mode = tool_uploadcourse_processor::MODE_CREATE_NEW;
+        $updatemode = tool_uploadcourse_processor::UPDATE_NOTHING;
+        $data = array('summary' => 'summary', 'fullname' => 'taken', 'category' => '1');
+        $importoptions = array('shortnametemplate' => '%f');
+        $co = new tool_uploadcourse_course($mode, $updatemode, $data, array(), $importoptions);
+        $this->assertFalse($co->prepare());
+        $this->assertArrayHasKey('generatedshortnamealreadyinuse', $co->get_errors());
+
+        // Generate a shortname to a course that already exists will be incremented.
+        $mode = tool_uploadcourse_processor::MODE_CREATE_ALL;
+        $updatemode = tool_uploadcourse_processor::UPDATE_NOTHING;
+        $data = array('summary' => 'summary', 'fullname' => 'taken', 'category' => '1');
+        $importoptions = array('shortnametemplate' => '%f');
+        $co = new tool_uploadcourse_course($mode, $updatemode, $data, array(), $importoptions);
+        $this->assertTrue($co->prepare());
+        $this->assertArrayHasKey('courseshortnamegenerated', $co->get_statuses());
+        $this->assertArrayHasKey('courseshortnameincremented', $co->get_statuses());
     }
 
 }
diff --git a/admin/tool/uploadcourse/tests/helper_test.php b/admin/tool/uploadcourse/tests/helper_test.php
index a61fa674d9e..f81c59f4a55 100644
--- a/admin/tool/uploadcourse/tests/helper_test.php
+++ b/admin/tool/uploadcourse/tests/helper_test.php
@@ -36,13 +36,19 @@ global $CFG;
 class tool_uploadcourse_helper_testcase extends advanced_testcase {
 
     public function test_generate_shortname() {
-        $data = (object) array('fullname' => 'Ah Bh Ch 01 02 03', 'idnumber' => 'ID123');
+        $data = (object) array('fullname' => 'Ah bh Ch 01 02 03', 'idnumber' => 'ID123');
 
         $this->assertSame($data->fullname, tool_uploadcourse_helper::generate_shortname($data, '%f'));
         $this->assertSame($data->idnumber, tool_uploadcourse_helper::generate_shortname($data, '%i'));
+        $this->assertSame('Ah Bh Ch', tool_uploadcourse_helper::generate_shortname($data, '%~8f'));
         $this->assertSame('AH BH CH', tool_uploadcourse_helper::generate_shortname($data, '%+8f'));
         $this->assertSame('id123', tool_uploadcourse_helper::generate_shortname($data, '%-i'));
-        $this->assertSame('[Ah Bh Ch] = ID123', tool_uploadcourse_helper::generate_shortname($data, '[%8f] = %i'));
+        $this->assertSame('[Ah bh Ch] = ID123', tool_uploadcourse_helper::generate_shortname($data, '[%8f] = %i'));
+        $this->assertSame('0', tool_uploadcourse_helper::generate_shortname($data, '0'));
+        $this->assertSame('%unknown', tool_uploadcourse_helper::generate_shortname($data, '%unknown'));
+
+        $this->assertNull(tool_uploadcourse_helper::generate_shortname($data, ''));
+        $this->assertNull(tool_uploadcourse_helper::generate_shortname(array(), '%f'));
     }
 
     public function test_get_course_formats() {
@@ -165,6 +171,12 @@ class tool_uploadcourse_helper_testcase extends advanced_testcase {
         $this->assertEquals($bcinfo->original_course_id, $c2->id);
         $this->assertEquals($bcinfo->original_course_fullname, $c2->fullname);
 
+        // Get a course that does not exist.
+        $errors = array();
+        $dir = tool_uploadcourse_helper::get_restore_content_dir(null, 'DoesNotExist', $errors);
+        $this->assertFalse($dir);
+        $this->assertArrayHasKey('coursetorestorefromdoesnotexist', $errors);
+
         // Cleaning content directories.
         $oldcfg = isset($CFG->keeptempdirectoriesonbackup) ? $CFG->keeptempdirectoriesonbackup : false;
         $dir = "$CFG->tempdir/backup/$dir";
diff --git a/admin/tool/uploadcourse/tests/processor_test.php b/admin/tool/uploadcourse/tests/processor_test.php
index 8aee781a219..648fcc6d936 100644
--- a/admin/tool/uploadcourse/tests/processor_test.php
+++ b/admin/tool/uploadcourse/tests/processor_test.php
@@ -166,4 +166,60 @@ class tool_uploadcourse_processor_testcase extends advanced_testcase {
         $this->assertEquals('ID123: Course 1', $c->shortname);
     }
 
+    public function test_empty_csv() {
+        $this->resetAfterTest(true);
+
+        $content = array();
+        $content = implode("\n", $content);
+        $iid = csv_import_reader::get_new_iid('uploadcourse');
+        $cir = new csv_import_reader($iid, 'uploadcourse');
+        $cir->load_csv_content($content, 'utf-8', 'comma');
+        $cir->init();
+
+        $options = array('mode' => tool_uploadcourse_processor::MODE_CREATE_NEW);
+        $this->setExpectedException('moodle_exception');
+        $p = new tool_uploadcourse_processor($cir, $options, array());
+    }
+
+    public function test_not_enough_columns() {
+        $this->resetAfterTest(true);
+
+        $content = array(
+            "shortname",
+            "c1",
+        );
+        $content = implode("\n", $content);
+        $iid = csv_import_reader::get_new_iid('uploadcourse');
+        $cir = new csv_import_reader($iid, 'uploadcourse');
+        $cir->load_csv_content($content, 'utf-8', 'comma');
+        $cir->init();
+
+        $options = array('mode' => tool_uploadcourse_processor::MODE_CREATE_NEW);
+        $this->setExpectedException('moodle_exception');
+        $p = new tool_uploadcourse_processor($cir, $options, array());
+    }
+
+    public function test_preview() {
+        global $DB;
+        $this->resetAfterTest(true);
+
+        $content = array(
+            "shortname,fullname,summary",
+            "c1,Course 1,Course 1 summary",
+            "c2,Course 2,Course 2 summary",
+        );
+        $content = implode("\n", $content);
+        $iid = csv_import_reader::get_new_iid('uploadcourse');
+        $cir = new csv_import_reader($iid, 'uploadcourse');
+        $cir->load_csv_content($content, 'utf-8', 'comma');
+        $cir->init();
+
+        $options = array('mode' => tool_uploadcourse_processor::MODE_CREATE_ALL);
+        $defaults = array('category' => '1');
+
+        $p = new tool_uploadcourse_processor($cir, $options, $defaults);
+        // Nothing special to expect here, just make sure no exceptions are thrown.
+        $p->preview();
+    }
+
 }