MDL-75168 tag: cleanup module tag instances upon course deletion.

lib/db/upgrade.php

@@ -2720,5 +2720,16 @@ function xmldb_main_upgrade($oldversion) {
         upgrade_main_savepoint(true, 2021051707.05);
     }
 
+    if ($oldversion < 2021051710.03) {
+
+        // Remove any orphaned tag instance records (pointing to non-existing context).
+        $DB->delete_records_select('tag_instance', 'NOT EXISTS (
+            SELECT ctx.id FROM {context} ctx WHERE ctx.id = {tag_instance}.contextid
+        )');
+
+        // Main savepoint reached.
+        upgrade_main_savepoint(true, 2021051710.03);
+    }
+
     return true;
 }

lib/moodlelib.php

@@ -5151,6 +5151,10 @@ function remove_course_contents($courseid, $showfeedback = true, array $options
                         question_delete_activity($cm);
                         // Notify the competency subsystem.
                         \core_competency\api::hook_course_module_deleted($cm);
+
+                        // Delete all tag instances associated with the instance of this module.
+                        core_tag_tag::delete_instances("mod_{$modname}", null, context_module::instance($cm->id)->id);
+                        core_tag_tag::remove_all_item_tags('core', 'course_modules', $cm->id);
                     }
                     if (function_exists($moddelete)) {
                         // This purges all module data in related tables, extra user prefs, settings, etc.

version.php

@@ -29,7 +29,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$version  = 2021051710.02;              // 20210517      = branching date YYYYMMDD - do not modify!
+$version  = 2021051710.03;              // 20210517      = branching date YYYYMMDD - do not modify!
                                         //         RR    = release increments - 00 in DEV branches.
                                         //           .XX = incremental changes.
 $release  = '3.11.10+ (Build: 20220922)';// Human-friendly version name