MDL-25659 fixed borked creation of enrol instances enrol/database, fi…

…xed detection of misconfigured sync
DavidSichau · Dec 13, 2010 · 883deb3 · 883deb3
1 parent 12c3ba9
commit 883deb3
Showing 1 changed file with 52 additions and 33 deletions.
diff --git a/enrol/database/lib.php b/enrol/database/lib.php
@@ -271,43 +271,19 @@ public function sync_enrolments() {
             $roles[$role->$localrolefield] = $role->id;
         }
 
-        // first find all existing courses with enrol instance
-        $sql = "SELECT c.id, c.visible, c.$localcoursefiled AS mapping, e.id AS enrolid
-                  FROM {course} c
-                  JOIN {enrol} e ON (e.courseid = c.id AND e.enrol = 'database')";
-        $existing = array();
-        $rs = $DB->get_recordset_sql($sql); // watch out for idnumber duplicates
-        foreach ($rs as $course) {
-            if (empty($course->mapping)) {
-                continue;
-            }
-            $existing[$course->mapping] = $course;
-        }
-        $rs->close();
-
-        // add necessary enrol instances that are not present yet;
+        // get a list of courses to be synced that are in external table
+        $externalcourses = array();
         $sql = $this->db_get_sql($table, array(), array($coursefield), true);
         if ($rs = $extdb->Execute($sql)) {
             if (!$rs->EOF) {
-                $sql = "SELECT c.id, c.visible
-                          FROM {course} c
-                          JOIN {enrol} e ON (e.courseid = c.id AND e.enrol = 'database')
-                         WHERE c.$localcoursefiled = :mapping";
-                $params = array();
                 while ($mapping = $rs->FetchRow()) {
                     $mapping = reset($mapping);
                     $mapping = $this->db_decode($mapping);
-                    if (!empty($mapping) and !isset($existing[$mapping])) {
-                        $params['mapping'] = $mapping;
-                        if ($course = $DB->get_record_sql($sql, $params, IGNORE_MULTIPLE)) {
-                            $new = new stdClass();
-                            $new->id      = $course->id;
-                            $new->visible = $course->visible;
-                            $new->mapping = $mapping;
-                            $new->enrolid = $this->add_instance($course);
-                            $existing[$mapping] = $new;
-                        }
+                    if (empty($mapping)) {
+                        // invalid mapping
+                        continue;
                     }
+                    $externalcourses[$mapping] = true;
                 }
             }
             $rs->Close();
@@ -316,6 +292,50 @@ public function sync_enrolments() {
             $extdb->Close();
             return;
         }
+        $preventfullunenrol = empty($externalcourses);
+        if ($preventfullunenrol and $unenrolaction == ENROL_EXT_REMOVED_UNENROL) {
+            debugging('Preventing unenrolment of all current users, because it might result in major data loss, there has to be at least one record in external enrol table, sorry.');
+        }
+
+        // first find all existing courses with enrol instance
+        $existing = array();
+        $sql = "SELECT c.id, c.visible, c.$localcoursefiled AS mapping, e.id AS enrolid
+                  FROM {course} c
+                  JOIN {enrol} e ON (e.courseid = c.id AND e.enrol = 'database')";
+        $rs = $DB->get_recordset_sql($sql); // watch out for idnumber duplicates
+        foreach ($rs as $course) {
+            if (empty($course->mapping)) {
+                continue;
+            }
+            $existing[$course->mapping] = $course;
+        }
+        $rs->close();
+
+        // add necessary enrol instances that are not present yet
+        $sql = "SELECT c.id, c.visible, c.$localcoursefiled AS mapping
+                  FROM {course} c
+             LEFT JOIN {enrol} e ON (e.courseid = c.id AND e.enrol = 'database')
+                 WHERE e.id IS NULL AND c.$localcoursefiled <> ?";
+        $rs = $DB->get_recordset_sql($sql, array($DB->sql_empty()));
+        foreach ($rs as $course) {
+            if (empty($course->mapping)) {
+                continue;
+            }
+            if (!isset($externalcourses[$course->mapping])) {
+                // course not synced
+                continue;
+            }
+            if (isset($existing[$course->mapping])) {
+                // some duplicate, sorry
+                continue;
+            }
+            $course->enrolid = $this->add_instance($course);
+            $existing[$course->mapping] = $course;
+        }
+        $rs->close();
+
+        // free memory
+        unset($externalcourses);
 
         // sync enrolments
         $ignorehidden = $this->get_config('ignorehiddencourses');
@@ -426,9 +446,8 @@ public function sync_enrolments() {
 
             // deal with enrolments removed from external table
             if ($unenrolaction == ENROL_EXT_REMOVED_UNENROL) {
-                // unenrol
-                if (!empty($requested_roles)) {
-                    // we might get some error or connection problem, better not unenrol everybody
+                if (!$preventfullunenrol) {
+                    // unenrol
                     foreach ($current_status as $userid=>$status) {
                         if (isset($requested_roles[$userid])) {
                             continue;