There are two different code paths for getting translatable strings out of templates: 1) extract_messages_from_templates() in LangInstaller.pm which handles js-files and the templates that use i18n.inc, 2) tmpl_process3.pl which uses misc/translation/xgettext.pl to parse and extract strings out of tt-files. The t/LangInstaller.t only tests the first one, there are no tests whatsoever for the second.
Is this still valid?