Merge branch 'MDL-37654_master' of https://github.com/markn86/moodle

diff --combined course/lib.php
index 241580f,af4fc55..5b901b2
--- 1/course/lib.php
--- 2/course/lib.php
+++ b/course/lib.php
@@@ -356,7 -356,7 +356,7 @@@ function print_log($course, $user=0, $d
      echo $OUTPUT->paging_bar($totalcount, $page, $perpage, "$url&perpage=$perpage");
  
      $table = new html_table();
 -    $table->classes = array('logtable','generalbox');
 +    $table->classes = array('logtable','generaltable');
      $table->align = array('right', 'left', 'left');
      $table->head = array(
          get_string('time'),
@@@ -1144,8 -1144,7 +1144,8 @@@ function get_module_metadata($course, $
          // NOTE: this is legacy stuff, module subtypes are very strongly discouraged!!
          $gettypesfunc =  $modname.'_get_types';
          if (function_exists($gettypesfunc)) {
 -            if ($types = $gettypesfunc()) {
 +            $types = $gettypesfunc();
 +            if (is_array($types) && count($types) > 0) {
                  $group = new stdClass();
                  $group->name = $modname;
                  $group->icon = $OUTPUT->pix_icon('icon', '', $modname, array('class' => 'icon'));
@@@ -1194,11 -1193,7 +1194,11 @@@
              $module->archetype = plugin_supports('mod', $modname, FEATURE_MOD_ARCHETYPE, MOD_ARCHETYPE_OTHER);
              $modlist[$course->id][$modname] = $module;
          }
 -        $return[$modname] = $modlist[$course->id][$modname];
 +        if (isset($modlist[$course->id][$modname])) {
 +            $return[$modname] = $modlist[$course->id][$modname];
 +        } else {
 +            debugging("Invalid module metadata configuration for {$modname}");
 +        }
      }
  
      return $return;
@@@ -1665,6 -1660,41 +1665,6 @@@ function can_edit_in_category($category
      return has_any_capability(array('moodle/category:manage', 'moodle/course:create'), $context);
  }
  
 -/**
 - * Prints the turn editing on/off button on course/index.php or course/category.php.
 - *
 - * @param integer $categoryid The id of the category we are showing, or 0 for system context.
 - * @return string HTML of the editing button, or empty string, if this user is not allowed
 - *      to see it.
 - */
 -function update_category_button($categoryid = 0) {
 -    global $CFG, $PAGE, $OUTPUT;
 -
 -    // Check permissions.
 -    if (!can_edit_in_category($categoryid)) {
 -        return '';
 -    }
 -
 -    // Work out the appropriate action.
 -    if ($PAGE->user_is_editing()) {
 -        $label = get_string('turneditingoff');
 -        $edit = 'off';
 -    } else {
 -        $label = get_string('turneditingon');
 -        $edit = 'on';
 -    }
 -
 -    // Generate the button HTML.
 -    $options = array('categoryedit' => $edit, 'sesskey' => sesskey());
 -    if ($categoryid) {
 -        $options['id'] = $categoryid;
 -        $page = 'category.php';
 -    } else {
 -        $page = 'index.php';
 -    }
 -    return $OUTPUT->single_button(new moodle_url('/course/' . $page, $options), $label, 'get');
 -}
 -
  /**
   * Print courses in category. If category is 0 then all courses are printed.
   * @param int|stdClass $category category object or id.
@@@ -2193,15 -2223,22 +2193,22 @@@ function course_delete_module($cmid) 
      if (file_exists($modlib)) {
          require_once($modlib);
      } else {
-         throw new moodle_exception("This module is missing mod/$modulename/lib.php", '', '',
-             null, 'failedtodeletemodulemissinglibfile');
+         throw new moodle_exception('cannotdeletemodulemissinglib', '', '', null,
+             "Cannot delete this module as the file mod/$modulename/lib.php is missing.");
      }
  
-     $deleteinstancefunction = $modulename . "_delete_instance";
+     $deleteinstancefunction = $modulename . '_delete_instance';
  
+     // Ensure the delete_instance function exists for this module.
+     if (!function_exists($deleteinstancefunction)) {
+         throw new moodle_exception('cannotdeletemodulemissingfunc', '', '', null,
+             "Cannot delete this module as the function {$modulename}_delete_instance is missing in mod/$modulename/lib.php.");
+     }
+ 
+     // Call the delete_instance function, if it returns false throw an exception.
      if (!$deleteinstancefunction($cm->instance)) {
-         throw new moodle_exception("Could not delete the $modulename (instance)", '', '',
-             null, 'failedtodeletemoduleinstance');
+         throw new moodle_exception('cannotdeletemoduleinstance', '', '', null,
+             "Cannot delete the module $modulename (instance).");
      }
  
      // Remove all module files in case modules forget to do that.
@@@ -2240,8 -2277,8 +2247,8 @@@
  
      // Delete module from that section.
      if (!delete_mod_from_section($cm->id, $cm->section)) {
-         throw new moodle_exception("Could not delete the $modulename from section", '', '',
-             null, 'failedtodeletemodulefromsection');
+         throw new moodle_exception('cannotdeletemodulefromsection', '', '', null,
+             "Cannot delete the module $modulename (instance) from section.");
      }
  
      // Trigger a mod_deleted event with information about this module.
@@@ -3802,6 -3839,16 +3809,6 @@@ function include_course_ajax($course, $
              )), null, true);
      }
  
 -    // Include blocks dragdrop
 -    $params = array(
 -        'courseid' => $course->id,
 -        'pagetype' => $PAGE->pagetype,
 -        'pagelayout' => $PAGE->pagelayout,
 -        'subpage' => $PAGE->subpage,
 -        'regions' => $PAGE->blocks->get_regions(),
 -    );
 -    $PAGE->requires->yui_module('moodle-core-blocks', 'M.core_blocks.init_dragdrop', array($params), null, true);
 -
      // Require various strings for the command toolbox
      $PAGE->requires->strings_for_js(array(
              'moveleft',