MDL-59458 mod_data: Fix sorting data query

* When activating sorting on a different field than the original field
the list of records is empty

mod/data/lib.php

@@ -3826,7 +3826,8 @@ function data_get_advanced_search_sql($sort, $data, $recordids, $selectdata, $so
 
     // Find the field we are sorting on
     if ($sort > 0 or data_get_field_from_id($sort, $data)) {
-        $selectdata .= ' AND c.fieldid = :sort';
+        $selectdata .= ' AND c.fieldid = :sort AND s.recordid = r.id';
+        $nestselectsql .= ',{data_content} s ';
     }
 
     // If there are no record IDs then return an sql statment that will return no rows.

mod/data/locallib.php

@@ -1116,7 +1116,7 @@ function data_search_entries($data, $cm, $context, $mode, $currentgroup, $search
     $namefields = $userfieldsapi->get_sql('u', false, '', '', false)->selects;
 
     // Find the field we are sorting on.
-    if ($sort <= 0 or !$sortfield = data_get_field_from_id($sort, $data)) {
+    if ($sort <= 0 || !($sortfield = data_get_field_from_id($sort, $data))) {
 
         switch ($sort) {
             case DATA_LASTNAME:
@@ -1168,7 +1168,7 @@ function data_search_entries($data, $cm, $context, $mode, $currentgroup, $search
 
     } else {
 
-        $sortcontent = $DB->sql_compare_text('c.' . $sortfield->get_sort_field());
+        $sortcontent = $DB->sql_compare_text('s.' . $sortfield->get_sort_field());
         $sortcontentfull = $sortfield->get_sort_sql($sortcontent);
 
         $what = ' DISTINCT r.id, r.approved, r.timecreated, r.timemodified, r.userid, r.groupid, r.dataid, ' . $namefields . ',
@@ -1179,7 +1179,8 @@ function data_search_entries($data, $cm, $context, $mode, $currentgroup, $search
                      AND r.dataid = :dataid
                      AND r.userid = u.id ';
         if (!$advanced) {
-            $where .= 'AND c.fieldid = :sort';
+            $where .= 'AND s.fieldid = :sort AND s.recordid = r.id';
+            $tables .= ',{data_content} s ';
         }
         $params['dataid'] = $data->id;
         $params['sort'] = $sort;

mod/data/tests/locallib_test.php

@@ -0,0 +1,118 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+namespace mod_data;
+
+use mod_data\external\record_exporter;
+
+defined('MOODLE_INTERNAL') || die();
+
+global $CFG;
+require_once($CFG->dirroot . '/mod/data/locallib.php');
+
+/**
+ * Unit tests for locallib.php
+ *
+ * @package    mod_data
+ * @copyright  2022 Laurent David <laurent.david@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class locallib_test extends \advanced_testcase {
+
+    /**
+     * Confirms that search is working
+     * @covers ::data_search_entries
+     */
+    public function test_data_search_entries() {
+        $this->resetAfterTest();
+        $this->setAdminUser();
+        $course = $this->getDataGenerator()->create_course();
+        $record = new \stdClass();
+        $record->course = $course->id;
+        $record->name = "Mod data delete test";
+        $record->intro = "Some intro of some sort";
+
+        $module = $this->getDataGenerator()->create_module('data', $record);
+        $titlefield = $this->getDataGenerator()->get_plugin_generator('mod_data')->create_field(
+            (object) [
+                'name' => 'title',
+                'type' => 'text',
+                'required' => 1
+            ],
+            $module);
+        $captionfield = $this->getDataGenerator()->get_plugin_generator('mod_data')->create_field(
+            (object) [
+                'name' => 'caption',
+                'type' => 'text',
+                'required' => 1
+            ],
+            $module);
+        $this->getDataGenerator()->get_plugin_generator('mod_data')->create_entry($module, [
+            $titlefield->field->id => 'Entry 1',
+            $captionfield->field->id => 'caption'
+        ]);
+        $this->getDataGenerator()->get_plugin_generator('mod_data')->create_entry($module, [
+            $titlefield->field->id => 'Entry 2',
+            $captionfield->field->id => ''
+        ]);
+        $cm = get_coursemodule_from_id('data', $module->cmid);
+        // Search for entries without any search query set, we should return them all.
+        list($records, $maxcount, $totalcount, $page, $nowperpage, $sort, $mode) =
+            data_search_entries($module, $cm, \context_course::instance($course->id), 'list', 0);
+        $this->assertCount(2, $records);
+        // Search for entries for "caption" we should return only one of them.
+        list($records, $maxcount, $totalcount, $page, $nowperpage, $sort, $mode) =
+            data_search_entries($module, $cm, \context_course::instance($course->id), 'list', 0, 'caption');
+        $this->assertCount(1, $records);
+        // Same search but we order by title.
+        list($records, $maxcount, $totalcount, $page, $nowperpage, $sort, $mode) =
+            data_search_entries($module, $cm, \context_course::instance($course->id), 'list', 0, 'caption',
+                $titlefield->field->id, 'ASC');
+        $this->assertCount(1, $records);
+        $this->assert_record_entries_contains($records, $captionfield->field->id, 'caption');
+
+        // Now with advanced search.
+        $defaults = [];
+        $fn = $ln = ''; // Defaults for first and last name.
+        // Force value for advanced search.
+        $_GET['f_' . $captionfield->field->id] = 'caption';
+        list($searcharray, $searchtext) = data_build_search_array($module, false, [], $defaults, $fn, $ln);
+        list($records, $maxcount, $totalcount, $page, $nowperpage, $sort, $mode) =
+            data_search_entries($module, $cm, \context_course::instance($course->id), 'list', 0, $searchtext,
+                $titlefield->field->id, 'ASC', 0, 0, true, $searcharray);
+        $this->assertCount(1, $records);
+        $this->assert_record_entries_contains($records, $captionfield->field->id, 'caption');
+    }
+
+    /**
+     * Assert that all records contains a value for the matching field id.
+     *
+     * @param array $records
+     * @param int $fieldid
+     * @param string $content
+     * @return void
+     */
+    private function assert_record_entries_contains($records, $fieldid, $content) {
+        global $DB;
+        foreach ($records as $record) {
+            $fieldscontent = $DB->get_records('data_content', ['recordid' => $record->id]);
+            foreach ($fieldscontent as $fieldcontent) {
+                if ($fieldcontent->id == $fieldid) {
+                    $this->assertStringContainsString($fieldcontent->content, $content);
+                }
+            }
+        }
+    }
+}