          for localedir in reversed(settings.LOCALE_PATHS):
              translation = self._new_gnu_trans(localedir)
              self.merge(translation)
  
      def _add_fallback(self):
          """Sets the GNUTranslations() fallback with the default language."""
          # Don't set a fallback for the default language or any English variant
          # (as it's empty, so it'll ALWAYS fall back to the default language)
          if self.__language == settings.LANGUAGE_CODE or self.__language.startswith('en'):
              return
 
</s> remove         default_translation = translation(settings.LANGUAGE_CODE)
 </s> add         if self.domain == 'django':
            # Get from cache
            default_translation = translation(settings.LANGUAGE_CODE)
        else:
            default_translation = DjangoTranslation(
                settings.LANGUAGE_CODE, domain=self.domain, localedirs=localedirs
            ) </s> remove     def __init__(self, language):
 </s> add     domain = 'django'

    def __init__(self, language, domain=None, localedirs=None): </s> remove         self._init_translation_catalog()
        self._add_installed_apps_translations()
 </s> add         if self.domain == 'django':
            if localedirs is not None:
                # A module-level cache is used for caching 'django' translations
                warnings.warn("localedirs is ignored when domain is 'django'.", RuntimeWarning)
                localedirs = None
            self._init_translation_catalog()

        if localedirs:
            for localedir in localedirs:
                translation = self._new_gnu_trans(localedir)
                self.merge(translation)
        else:
            self._add_installed_apps_translations()
 </s> remove     Returns a translation object.
 </s> add     Returns a translation object in the default 'django' domain. </s> remove     # add the filesystem paths listed in the LOCALE_PATHS setting
    paths.extend(reversed(settings.LOCALE_PATHS))
    # first load all english languages files for defaults
    for path in paths:
        try:
            catalog = gettext_module.translation(domain, path, ['en'])
            t.update(catalog._catalog)
        except IOError:
            pass
        else:
            # 'en' is the selected language and at least one of the packages
            # listed in `packages` has an 'en' catalog
            if en_selected:
                en_catalog_missing = False
    # next load the settings.LANGUAGE_CODE translations if it isn't english
    if default_locale != 'en':
        for path in paths:
            try:
                catalog = gettext_module.translation(domain, path, [default_locale])
            except IOError:
                catalog = None
            if catalog is not None:
                t.update(catalog._catalog)
    # last load the currently selected language, if it isn't identical to the default.
    if locale != default_locale:
        # If the currently selected language is English but it doesn't have a
        # translation catalog (presumably due to being the language translated
        # from) then a wrong language catalog might have been loaded in the
        # previous step. It needs to be discarded.
        if en_selected and en_catalog_missing:
            t = {}
        else:
            locale_t = {}
            for path in paths:
                try:
                    catalog = gettext_module.translation(domain, path, [locale])
                except IOError:
                    catalog = None
                if catalog is not None:
                    locale_t.update(catalog._catalog)
            if locale_t:
                t = locale_t
 </s> add     trans = DjangoTranslation(locale, domain=domain, localedirs=paths)
    trans_cat = trans._catalog

    def _add_fallback(self, localedirs=None):
          for localedir in reversed(settings.LOCALE_PATHS):
              translation = self._new_gnu_trans(localedir)
              self.merge(translation)
  
    def _add_fallback(self, localedirs=None):
          """Sets the GNUTranslations() fallback with the default language."""
          # Don't set a fallback for the default language or any English variant
          # (as it's empty, so it'll ALWAYS fall back to the default language)
          if self.__language == settings.LANGUAGE_CODE or self.__language.startswith('en'):
              return
keep keep keep keep replace keep keep keep keep keep
 Reused the DjangoTranslation class for the javascript_catalog view

Thanks Tim Graham and Cristiano Coelho for the reviews.
Refs #26328, #26319. 
django/utils/translation/trans_real.py