Don't include :und in known_locales

CHANGELOG.md

@@ -1,5 +1,15 @@
 # Changelog
 
+## Cldr v2.37.1
+
+This is the changelog for Cldr v2.37.1 released on May 7th, 2023.  For older changelogs please consult the release tag on [GitHub](https://github.com/elixir-cldr/cldr/tags)
+
+**Note that `ex_cldr` version 2.33.0 and later are supported on Elixir 1.11 and later only.**
+
+### Bug Fixes
+
+* Don't include `:und` in the list returned by `Cldr.known_locale_names/1` since that function is commonly used to enumerate the configured locales and ultimately used to generate UI elements. `:und` is not a useful locale to select so its inclusion, which was added in `ex_cldr version 2.37.0` is inappropriate and now reverted.
+
 ## Cldr v2.37.0
 
 This is the changelog for Cldr v2.37.0 released on April 28th, 2023.  For older changelogs please consult the release tag on [GitHub](https://github.com/elixir-cldr/cldr/tags)

lib/cldr/backend/cldr_backend.ex

@@ -17,11 +17,7 @@ defmodule Cldr.Backend do
 
       alias Cldr.{Locale, Config, LanguageTag}
 
-      # We used to omit :und but the spec says thats the ultimate
-      # fallback so its back!
-
-      # @omit_locales [Config.root_locale_name()]
-      @omit_locales []
+      @omit_locales [Config.root_locale_name()]
       @known_locale_names Locale.Loader.known_locale_names(config) -- @omit_locales
 
       def known_locale_names do

lib/cldr/config/rbnf_config.ex

@@ -75,7 +75,7 @@ defmodule Cldr.Rbnf.Config do
          :ff, :fi, :fil, :fo, :fr, :"fr-BE", :"fr-CH", :ga, :he, :hi, :hr, :hu, :hy,
          :id, :is, :it, :ja, :ka, :kk, :kl, :km, :ko, :ky, :lb, :lo, :lrc, :lt, :lv,
          :mk, :ms, :mt, :my, :ne, :nl, :nn, :no, :pl, :pt, :"pt-PT", :qu, :ro, :ru, :se,
-         :sk, :sl, :sq, :sr, :"sr-Latn", :su, :sv, :sw, :ta, :th, :tr, :uk, :und, :vec,
+         :sk, :sl, :sq, :sr, :"sr-Latn", :su, :sv, :sw, :ta, :th, :tr, :uk, :vec,
          :vi, :yue, :"yue-Hans", :zh, :"zh-Hant"]
 
     """

lib/cldr/locale.ex

@@ -445,7 +445,7 @@ defmodule Cldr.Locale do
   end
 
   defp known_locale(locale_name, _tags, backend) when is_atom(locale_name) do
-    Enum.find(backend.known_locale_names(), &(locale_name == &1))
+    Enum.find(backend.known_locale_names() ++ [Cldr.Config.root_locale_name()], &(locale_name == &1))
   end
 
   defp known_rbnf_locale_name(locale_name, _tags, backend) do
@@ -1809,7 +1809,13 @@ defmodule Cldr.Locale do
     %{language_tag | gettext_locale_name: gettext_locale_name}
   end
 
+  @root_locale_name Cldr.Config.root_locale_name()
+
   @spec cldr_locale_name(Cldr.LanguageTag.t()) :: locale_name() | nil
+  defp cldr_locale_name(%LanguageTag{language: @root_locale_name}) do
+    @root_locale_name
+  end
+
   defp cldr_locale_name(%LanguageTag{} = language_tag) do
     first_match(language_tag, &known_locale(&1, &2, language_tag.backend)) ||
       Cldr.known_locale_name(language_tag.requested_locale_name, language_tag.backend)

mix.exs

@@ -1,7 +1,7 @@
 defmodule Cldr.Mixfile do
   use Mix.Project
 
-  @version "2.37.0"
+  @version "2.37.1"
 
   def project do
     [

test/config_locales_test.exs

@@ -90,7 +90,7 @@ defmodule Cldr.Config.Test do
     end)
 
     assert apply(Cldr.Config.Test.PosixDefaultLocale, :known_locale_names, []) ==
-             [:en, :"en-GB", :und]
+             [:en, :"en-GB"]
 
     assert apply(Cldr.Config.Test.PosixDefaultLocale, :default_locale, []).cldr_locale_name ==
              :"en-GB"

test/parent_locale_test.exs

@@ -5,10 +5,13 @@ defmodule Cldr.Locale.Parent.Test do
     assert Cldr.Locale.parent("und") ==
              {:error, {Cldr.NoParentError, "The locale :und has no parent locale"}}
 
-    assert Cldr.Locale.parent("en-US") == TestBackend.Cldr.Locale.new("und")
-    assert Cldr.Locale.parent("en-US-u-va-POSIX") == TestBackend.Cldr.Locale.new("und-u-va-posix")
     assert Cldr.Locale.parent("en-AU") == TestBackend.Cldr.Locale.new("en-001")
+  end
+
+  test "parent is :und" do
+    assert Cldr.Locale.parent("en-US") == TestBackend.Cldr.Locale.new("und")
     assert Cldr.Locale.parent("ca") == TestBackend.Cldr.Locale.new("und")
+    assert Cldr.Locale.parent("en-US-u-va-POSIX") == TestBackend.Cldr.Locale.new("und-u-va-posix")
   end
 
   test "parent locale of en-001" do