eZINI:instance seems bugged when $rootDir parameter is used

The 7th parameter ($addArrayDefinition) passed to this method is marked as deprecated since 4.5, but in 5.4 we are able to verify that setting it largely changes the way in which $rootDir parameter is handled.

Consider the following example

• In an updated installation of eZPublish 5.4, with demo content, setup SiteURL in ezdemo_site_user and ezdemo_site_admin, so that each siteaccess has it's own siteURL

• Create a script and place it in ezplublish_legacy/bin/php

  <?php
  require_once 'autoload.php';
  
  $helper = new eZCacheHelper(
      $cli = eZCLI::instance(),
      $script = eZScript::instance(
          array(
              'description' => "Tester for legacy CS\n" .
                               "./bin/php/initester.phpt",
              'use-session' => false,
              'use-modules' => false,
              'use-extensions' => true
          )
      )
  );
  
  $script->startup();
  $script->initialize();
  
  $ini = eZINI::instance( 'site.ini', 'settings/siteaccess/ezdemo_site_user');
  $param = $ini->variable('SiteSettings', 'SiteURL');
  $cli->output( "SiteURL: $param" );
  
  $ini = eZINI::instance( 'site.ini.append.php', 'settings/siteaccess/ezdemo_site_user');
  $param = $ini->variable('SiteSettings', 'SiteURL');
  $cli->output( "SiteURL: $param" );
  
  $ini = eZINI::instance( 'site.ini', 'settings/siteaccess/ezdemo_site_user', null, null, false, true );
  $param = $ini->variable('SiteSettings', 'SiteURL');
  $cli->output( "SiteURL: $param" );
  
  $ini = eZINI::instance( 'site.ini.append.php', 'settings/siteaccess/ezdemo_site_user', null, null, false, true );
  $param = $ini->variable('SiteSettings', 'SiteURL');
  $cli->output( "SiteURL: $param" );
  
  $ini = eZINI::instance( 'site.ini', 'settings/siteaccess/ezdemo_site_user', null, null, false, false );
  $param = $ini->variable('SiteSettings', 'SiteURL');
  $cli->output( "SiteURL: $param" );
  
  $ini = eZINI::instance( 'site.ini.append.php', 'settings/siteaccess/ezdemo_site_user', null, null, false, false );
  $param = $ini->variable('SiteSettings', 'SiteURL');
  $cli->output( "SiteURL: $param" );
  
  $cli->output( 'execution done' );
  $script->shutdown();
  

Execute the script, from EZROOT, with the following command

php ezpublish/console --env=prod --siteaccess=ezdemo_site_admin ezpublish:legacy:script bin/php/initester.php

The expected result would be to see the SiteURL defined for ezdemo_site_user outputted in all cases, but when $addArrayDefinition is left as false (default value), $fileName needs to be set to site.ini.append.php in order for the proper value to be assumed. (otherwise value from default eng siteaccess is echoed