MDEV-13063 Server crashes in intern_plugin_lock or assertion...

MDEV-13063 Server crashes in intern_plugin_lock or assertion `plugin_ptr->ref_count == 1' fails in plugin_init

if a forced plugin is disabled (for any reason, e.g. invalid command-line
option) - it's an error

mysql-test/t/bootstrap.test

@@ -60,4 +60,10 @@ SHOW VARIABLES LIKE 'have_innodb';
 SELECT 'bug' as '' FROM INFORMATION_SCHEMA.ENGINES WHERE engine='innodb'
  and SUPPORT='YES';
 
+#
+# MDEV-13063 Server crashes in intern_plugin_lock or assertion `plugin_ptr->ref_count == 1' fails in plugin_init
+#
+--error 1
+--exec $MYSQLD_BOOTSTRAP_CMD --myisam_recover_options=NONE
+
 --echo End of 5.5 tests

sql/sql_plugin.cc

@@ -1359,7 +1359,7 @@ static int plugin_initialize(MEM_ROOT *tmp_root, struct st_plugin_int *plugin,
 
   if (options_only || state == PLUGIN_IS_DISABLED)
   {
-    ret= 0;
+    ret= !options_only && plugin_is_forced(plugin);
     goto err;
   }