From 1a25f1ec6dbc86247ca462e44c01065728b98a2c Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Sat, 10 Sep 2016 04:24:55 +0200
Subject: [PATCH 01/15] Make `MacOS.language` less opinionated.

---
 Library/Homebrew/os/mac.rb | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/os/mac.rb b/Library/Homebrew/os/mac.rb
index 0b01478253f1c..566f409930bc7 100644
--- a/Library/Homebrew/os/mac.rb
+++ b/Library/Homebrew/os/mac.rb
@@ -41,8 +41,12 @@ def cat
       version.to_sym
     end
 
+    def languages
+      @languages ||= Utils.popen_read("defaults", "read", ".GlobalPreferences", "AppleLanguages").scan(/[^ \n"(),]+/)
+    end
+
     def language
-      @language ||= Utils.popen_read("defaults", "read", ".GlobalPreferences", "AppleLanguages").delete(" \n\"()").sub(/,.*/, "")
+      languages.first
     end
 
     def active_developer_dir

From 929c594f41437f3a0a6d13fed2d596a0ba60435b Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Sat, 10 Sep 2016 17:15:58 +0200
Subject: [PATCH 02/15] Add test for `MacOS.languages`.

---
 Library/Homebrew/test/test_os_mac_language.rb | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/test/test_os_mac_language.rb b/Library/Homebrew/test/test_os_mac_language.rb
index 2cdd50917da18..709913000bb98 100644
--- a/Library/Homebrew/test/test_os_mac_language.rb
+++ b/Library/Homebrew/test/test_os_mac_language.rb
@@ -2,7 +2,15 @@
 require "os/mac"
 
 class OSMacLanguageTests < Homebrew::TestCase
+  LANGUAGE_REGEX = /\A[a-z]{2}(-[A-Z]{2})?(-[A-Z][a-z]{3})?\Z/
+
+  def test_languages_format
+    OS::Mac.languages.each do |language|
+      assert_match LANGUAGE_REGEX, language
+    end
+  end
+
   def test_language_format
-    assert_match(/\A[a-z]{2}(-[A-Z]{2})?\Z/, OS::Mac.language)
+    assert_match LANGUAGE_REGEX, OS::Mac.language
   end
 end

From f52116cd2622eff3ef1611e059bab8b96163a596 Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Wed, 14 Sep 2016 23:11:21 +0200
Subject: [PATCH 03/15] Add `language` stanza to cask DSL.

---
 Library/Homebrew/cask/lib/hbc/dsl.rb      | 26 +++++++++++++++++++++++
 Library/Homebrew/cask/lib/hbc/dsl/base.rb |  2 +-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/cask/lib/hbc/dsl.rb b/Library/Homebrew/cask/lib/hbc/dsl.rb
index 83c0bf1fb3316..69ade9a861735 100644
--- a/Library/Homebrew/cask/lib/hbc/dsl.rb
+++ b/Library/Homebrew/cask/lib/hbc/dsl.rb
@@ -64,6 +64,7 @@ class DSL
                             :depends_on,
                             :gpg,
                             :homepage,
+                            :language,
                             :license,
                             :name,
                             :sha256,
@@ -98,6 +99,31 @@ def homepage(homepage = nil)
       @homepage ||= homepage
     end
 
+    def language(*args, &block)
+      @language ||= {}
+
+      if !args.empty? && block_given?
+        args.each do |arg|
+          MacOS.languages.each_with_index do |l, index|
+            string_or_regex = arg == :default ? %r{^en} : arg
+            next unless l.match(string_or_regex)
+            next unless @language[:level].nil? || @language[:level] > index
+            @language = {
+                          block: block,
+                          level: index,
+                        }
+          end
+        end
+
+        if args.include?(:default)
+          # :default has to be the last language block in order to assign return value of the selected `language` block to `@language`
+          @language = @language[:block].call
+        end
+      else
+        @language
+      end
+    end
+
     def url(*args, &block)
       url_given = !args.empty? || block_given?
       return @url unless url_given
diff --git a/Library/Homebrew/cask/lib/hbc/dsl/base.rb b/Library/Homebrew/cask/lib/hbc/dsl/base.rb
index ccf93dae9a213..20a3cec619baa 100644
--- a/Library/Homebrew/cask/lib/hbc/dsl/base.rb
+++ b/Library/Homebrew/cask/lib/hbc/dsl/base.rb
@@ -8,7 +8,7 @@ def initialize(cask, command = SystemCommand)
         @command = command
       end
 
-      def_delegators :@cask, :token, :version, :caskroom_path, :staged_path, :appdir
+      def_delegators :@cask, :token, :version, :caskroom_path, :staged_path, :appdir, :language
 
       def system_command(executable, options = {})
         @command.run!(executable, options)

From 65fdfefc99e2308a406e57eb55cd2e32f107717f Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Sun, 18 Sep 2016 04:15:28 +0200
Subject: [PATCH 04/15] Add `language_eval` method.

---
 Library/Homebrew/cask/lib/hbc/cask.rb |  5 ++++-
 Library/Homebrew/cask/lib/hbc/dsl.rb  | 17 +++++++++--------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/Library/Homebrew/cask/lib/hbc/cask.rb b/Library/Homebrew/cask/lib/hbc/cask.rb
index 756b05b83fcb7..1e2056efc705e 100644
--- a/Library/Homebrew/cask/lib/hbc/cask.rb
+++ b/Library/Homebrew/cask/lib/hbc/cask.rb
@@ -11,7 +11,10 @@ def initialize(token, sourcefile_path: nil, dsl: nil, &block)
       @token = token
       @sourcefile_path = sourcefile_path
       @dsl = dsl || DSL.new(@token)
-      @dsl.instance_eval(&block) if block_given?
+      if block_given?
+        @dsl.instance_eval(&block)
+        @dsl.language_eval
+      end
     end
 
     DSL::DSL_METHODS.each do |method_name|
diff --git a/Library/Homebrew/cask/lib/hbc/dsl.rb b/Library/Homebrew/cask/lib/hbc/dsl.rb
index 69ade9a861735..a1b3280e66048 100644
--- a/Library/Homebrew/cask/lib/hbc/dsl.rb
+++ b/Library/Homebrew/cask/lib/hbc/dsl.rb
@@ -100,30 +100,31 @@ def homepage(homepage = nil)
     end
 
     def language(*args, &block)
-      @language ||= {}
-
       if !args.empty? && block_given?
         args.each do |arg|
           MacOS.languages.each_with_index do |l, index|
             string_or_regex = arg == :default ? %r{^en} : arg
             next unless l.match(string_or_regex)
-            next unless @language[:level].nil? || @language[:level] > index
+            next unless @language.nil? || @language[:level].nil? || @language[:level] > index
             @language = {
                           block: block,
                           level: index,
                         }
           end
         end
-
-        if args.include?(:default)
-          # :default has to be the last language block in order to assign return value of the selected `language` block to `@language`
-          @language = @language[:block].call
-        end
       else
+        language_eval
         @language
       end
     end
 
+
+    def language_eval
+      if @language.is_a?(Hash) && @language.key?(:block)
+        @language = @language[:block].call
+      end
+    end
+
     def url(*args, &block)
       url_given = !args.empty? || block_given?
       return @url unless url_given

From 87299af22547093a4efb9c4a5e06b55bb51f9ff7 Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Wed, 21 Sep 2016 21:56:59 +0200
Subject: [PATCH 05/15] Add test for `language` stanza.

---
 Library/Homebrew/cask/test/cask/dsl_test.rb | 33 +++++++++++++++++++++
 Library/Homebrew/os/mac.rb                  |  6 +++-
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/cask/test/cask/dsl_test.rb b/Library/Homebrew/cask/test/cask/dsl_test.rb
index ccf2f1a24816f..96095ed70b144 100644
--- a/Library/Homebrew/cask/test/cask/dsl_test.rb
+++ b/Library/Homebrew/cask/test/cask/dsl_test.rb
@@ -122,6 +122,39 @@
     end
   end
 
+  describe "language stanza" do
+    after(:each) do
+      ENV["HOMEBREW_LANGUAGES"] = nil
+    end
+
+    it "allows multilingual casks" do
+      cask = lambda {
+        Hbc::Cask.new("cask-with-apps") do
+          language "FIRST_LANGUAGE" do
+            :first
+          end
+
+          language %r{SECOND_LANGUAGE} do
+            :second
+          end
+
+          language :default do
+            :default
+          end
+        end
+      }
+
+      ENV["HOMEBREW_LANGUAGES"] = "FIRST_LANGUAGE"
+      cask.call.language.must_equal :first
+
+      ENV["HOMEBREW_LANGUAGES"] = "SECOND_LANGUAGE"
+      cask.call.language.must_equal :second
+
+      ENV["HOMEBREW_LANGUAGES"] = "THIRD_LANGUAGE"
+      cask.call.language.must_equal :default
+    end
+  end
+
   describe "app stanza" do
     it "allows you to specify app stanzas" do
       cask = Hbc::Cask.new("cask-with-apps") do
diff --git a/Library/Homebrew/os/mac.rb b/Library/Homebrew/os/mac.rb
index 566f409930bc7..854d39174c409 100644
--- a/Library/Homebrew/os/mac.rb
+++ b/Library/Homebrew/os/mac.rb
@@ -42,7 +42,11 @@ def cat
     end
 
     def languages
-      @languages ||= Utils.popen_read("defaults", "read", ".GlobalPreferences", "AppleLanguages").scan(/[^ \n"(),]+/)
+      if ENV["HOMEBREW_LANGUAGES"]
+        ENV["HOMEBREW_LANGUAGES"].split(",")
+      else
+        @languages ||= Utils.popen_read("defaults", "read", ".GlobalPreferences", "AppleLanguages").scan(/[^ \n"(),]+/)
+      end
     end
 
     def language

From 1e86c7d3ec8f7d1a82b01646fcc0f72d0f2c6ea8 Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Wed, 21 Sep 2016 22:13:01 +0200
Subject: [PATCH 06/15] Always fall back to `language :default`.

---
 Library/Homebrew/cask/lib/hbc/dsl.rb | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Library/Homebrew/cask/lib/hbc/dsl.rb b/Library/Homebrew/cask/lib/hbc/dsl.rb
index a1b3280e66048..624d62a7607e5 100644
--- a/Library/Homebrew/cask/lib/hbc/dsl.rb
+++ b/Library/Homebrew/cask/lib/hbc/dsl.rb
@@ -103,8 +103,7 @@ def language(*args, &block)
       if !args.empty? && block_given?
         args.each do |arg|
           MacOS.languages.each_with_index do |l, index|
-            string_or_regex = arg == :default ? %r{^en} : arg
-            next unless l.match(string_or_regex)
+            next unless arg == :default || l.match(arg)
             next unless @language.nil? || @language[:level].nil? || @language[:level] > index
             @language = {
                           block: block,

From b703c81ca6640ee2ff3d0489462c672a2aa18c0f Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Wed, 21 Sep 2016 22:19:04 +0200
Subject: [PATCH 07/15] Stub `MacOS.languages` instead of setting
 HOMEBREW_LANGUAGES.

---
 Library/Homebrew/cask/test/cask/dsl_test.rb | 10 +++-------
 Library/Homebrew/os/mac.rb                  |  4 ++--
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/Library/Homebrew/cask/test/cask/dsl_test.rb b/Library/Homebrew/cask/test/cask/dsl_test.rb
index 96095ed70b144..1e13d49f323a1 100644
--- a/Library/Homebrew/cask/test/cask/dsl_test.rb
+++ b/Library/Homebrew/cask/test/cask/dsl_test.rb
@@ -123,10 +123,6 @@
   end
 
   describe "language stanza" do
-    after(:each) do
-      ENV["HOMEBREW_LANGUAGES"] = nil
-    end
-
     it "allows multilingual casks" do
       cask = lambda {
         Hbc::Cask.new("cask-with-apps") do
@@ -144,13 +140,13 @@
         end
       }
 
-      ENV["HOMEBREW_LANGUAGES"] = "FIRST_LANGUAGE"
+      MacOS.stubs(languages: ["FIRST_LANGUAGE"])
       cask.call.language.must_equal :first
 
-      ENV["HOMEBREW_LANGUAGES"] = "SECOND_LANGUAGE"
+      MacOS.stubs(languages: ["SECOND_LANGUAGE"])
       cask.call.language.must_equal :second
 
-      ENV["HOMEBREW_LANGUAGES"] = "THIRD_LANGUAGE"
+      MacOS.stubs(languages: ["THIRD_LANGUAGE"])
       cask.call.language.must_equal :default
     end
   end
diff --git a/Library/Homebrew/os/mac.rb b/Library/Homebrew/os/mac.rb
index 854d39174c409..1b207a538bd13 100644
--- a/Library/Homebrew/os/mac.rb
+++ b/Library/Homebrew/os/mac.rb
@@ -42,10 +42,10 @@ def cat
     end
 
     def languages
-      if ENV["HOMEBREW_LANGUAGES"]
+      @languages ||= if ENV["HOMEBREW_LANGUAGES"]
         ENV["HOMEBREW_LANGUAGES"].split(",")
       else
-        @languages ||= Utils.popen_read("defaults", "read", ".GlobalPreferences", "AppleLanguages").scan(/[^ \n"(),]+/)
+        Utils.popen_read("defaults", "read", ".GlobalPreferences", "AppleLanguages").scan(/[^ \n"(),]+/)
       end
     end
 

From 546a91f78e67939e49df4984562f02b25e68aa72 Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Sun, 25 Sep 2016 20:43:03 +0200
Subject: [PATCH 08/15] =?UTF-8?q?Add=20`=E2=80=94language`=20option.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Library/Homebrew/cask/lib/hbc/cli.rb |  4 ++++
 Library/Homebrew/os/mac.rb           | 16 ++++++++++++----
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/Library/Homebrew/cask/lib/hbc/cli.rb b/Library/Homebrew/cask/lib/hbc/cli.rb
index 3f67e131ddc1c..f637ae7af5f72 100644
--- a/Library/Homebrew/cask/lib/hbc/cli.rb
+++ b/Library/Homebrew/cask/lib/hbc/cli.rb
@@ -179,6 +179,10 @@ def self.nice_listing(cask_list)
     def self.parser
       # If you modify these arguments, please update USAGE.md
       @parser ||= OptionParser.new do |opts|
+        opts.on("--language STRING") do
+          # handled in OS::Mac
+        end
+
         OPTIONS.each do |option, method|
           opts.on("#{option}" "PATH", Pathname) do |path|
             Hbc.public_send(method, path)
diff --git a/Library/Homebrew/os/mac.rb b/Library/Homebrew/os/mac.rb
index 1b207a538bd13..b2f0515a0a2bd 100644
--- a/Library/Homebrew/os/mac.rb
+++ b/Library/Homebrew/os/mac.rb
@@ -42,11 +42,19 @@ def cat
     end
 
     def languages
-      @languages ||= if ENV["HOMEBREW_LANGUAGES"]
-        ENV["HOMEBREW_LANGUAGES"].split(",")
-      else
-        Utils.popen_read("defaults", "read", ".GlobalPreferences", "AppleLanguages").scan(/[^ \n"(),]+/)
+      return @languages unless @languages.nil?
+
+      @languages = Utils.popen_read("defaults", "read", ".GlobalPreferences", "AppleLanguages").scan(/[^ \n"(),]+/)
+
+      if ENV["HOMEBREW_LANGUAGES"]
+        @languages = ENV["HOMEBREW_LANGUAGES"].split(",") + @languages
       end
+
+      if ARGV.value("language")
+        @languages = ARGV.value("language").split(",") + @languages
+      end
+
+      @languages = @languages.uniq
     end
 
     def language

From bc2d676b6f590d0ddd2987699624f6718384b641 Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Sun, 25 Sep 2016 22:13:44 +0200
Subject: [PATCH 09/15] Refactor logic to always choose first matched language.

---
 Library/Homebrew/cask/lib/hbc/dsl.rb        | 36 +++++++++++++--------
 Library/Homebrew/cask/test/cask/dsl_test.rb |  6 ++++
 2 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/Library/Homebrew/cask/lib/hbc/dsl.rb b/Library/Homebrew/cask/lib/hbc/dsl.rb
index 624d62a7607e5..bae395726f3ca 100644
--- a/Library/Homebrew/cask/lib/hbc/dsl.rb
+++ b/Library/Homebrew/cask/lib/hbc/dsl.rb
@@ -101,27 +101,37 @@ def homepage(homepage = nil)
 
     def language(*args, &block)
       if !args.empty? && block_given?
-        args.each do |arg|
-          MacOS.languages.each_with_index do |l, index|
-            next unless arg == :default || l.match(arg)
-            next unless @language.nil? || @language[:level].nil? || @language[:level] > index
-            @language = {
-                          block: block,
-                          level: index,
-                        }
-          end
-        end
+        @language_blocks ||= {}
+        @language_blocks[args] = block
       else
         language_eval
         @language
       end
     end
 
-
     def language_eval
-      if @language.is_a?(Hash) && @language.key?(:block)
-        @language = @language[:block].call
+      return if instance_variable_defined?(:@language)
+
+      return unless instance_variable_defined?(:@language_blocks)
+
+      default_key = @language_blocks.keys.detect { |key| key.include?(:default) }
+
+      MacOS.languages.each do |language|
+        @language_blocks.each do |regexes_or_strings, block|
+          if regexes_or_strings.include?(:default)
+            regexes_or_strings = regexes_or_strings - [:default] + [%r{^en}]
+          end
+
+          case language
+          when *regexes_or_strings
+            @language = block.call
+            return
+          end
+        end
       end
+
+      # fallback to :default
+      @language = default_key.nil? ? nil : @language_blocks[default_key].call
     end
 
     def url(*args, &block)
diff --git a/Library/Homebrew/cask/test/cask/dsl_test.rb b/Library/Homebrew/cask/test/cask/dsl_test.rb
index 1e13d49f323a1..f6fca3d2d1b9e 100644
--- a/Library/Homebrew/cask/test/cask/dsl_test.rb
+++ b/Library/Homebrew/cask/test/cask/dsl_test.rb
@@ -148,6 +148,12 @@
 
       MacOS.stubs(languages: ["THIRD_LANGUAGE"])
       cask.call.language.must_equal :default
+
+      MacOS.stubs(languages: ["THIRD_LANGUAGE", "SECOND_LANGUAGE", "FIRST_LANGUAGE"])
+      cask.call.language.must_equal :second
+
+      MacOS.stubs(languages: ["THIRD_LANGUAGE", "FIRST_LANGUAGE", "SECOND_LANGUAGE"])
+      cask.call.language.must_equal :first
     end
   end
 

From bc143bb4701eb4f5fdcd19036b9232a32f4e52ae Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Sun, 25 Sep 2016 22:47:31 +0200
Subject: [PATCH 10/15] Support `audit` for multilingual casks.

---
 Library/Homebrew/cask/lib/hbc/auditor.rb | 18 ++++++++++++++++++
 Library/Homebrew/cask/lib/hbc/dsl.rb     |  9 +++++++--
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/Library/Homebrew/cask/lib/hbc/auditor.rb b/Library/Homebrew/cask/lib/hbc/auditor.rb
index 6b0c1c4764373..7a6bb608fe9b3 100644
--- a/Library/Homebrew/cask/lib/hbc/auditor.rb
+++ b/Library/Homebrew/cask/lib/hbc/auditor.rb
@@ -1,6 +1,24 @@
 module Hbc
   class Auditor
     def self.audit(cask, audit_download: false, check_token_conflicts: false)
+      saved_languages = MacOS.instance_variable_get(:@languages)
+
+      if languages_blocks = cask.instance_variable_get(:@dsl).instance_variable_get(:@language_blocks)
+        languages_blocks.keys.map(&:first).each do |language|
+          ohai "Auditing language #{language.to_s}"
+          language = "en-US" if language == :default
+          MacOS.instance_variable_set(:@languages, [language])
+          audit_cask_instance(Hbc.load(cask.sourcefile_path), audit_download, check_token_conflicts)
+          CLI::Cleanup.run(cask.token) if audit_download
+        end
+      else
+        audit_cask_instance(cask, audit_download, check_token_conflicts)
+      end
+    ensure
+      MacOS.instance_variable_set(:@languages, saved_languages)
+    end
+
+    def self.audit_cask_instance(cask, audit_download, check_token_conflicts)
       download = audit_download && Download.new(cask)
       audit = Audit.new(cask, download:              download,
                               check_token_conflicts: check_token_conflicts)
diff --git a/Library/Homebrew/cask/lib/hbc/dsl.rb b/Library/Homebrew/cask/lib/hbc/dsl.rb
index bae395726f3ca..9970f83954766 100644
--- a/Library/Homebrew/cask/lib/hbc/dsl.rb
+++ b/Library/Homebrew/cask/lib/hbc/dsl.rb
@@ -122,8 +122,13 @@ def language_eval
             regexes_or_strings = regexes_or_strings - [:default] + [%r{^en}]
           end
 
-          case language
-          when *regexes_or_strings
+          regexes_or_strings.each do |regex_or_string|
+            if regex_or_string.class == language.class
+              next unless regex_or_string == language
+            else
+              next unless regex_or_string =~ language
+            end
+
             @language = block.call
             return
           end

From b5531e8ec1dab3e3beabf85e7e270738bc214492 Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Tue, 27 Sep 2016 22:23:13 +0200
Subject: [PATCH 11/15] Add Locale class to enable easier matching of locales.

---
 Library/Homebrew/cask/spec/locale_spec.rb | 72 +++++++++++++++++++++++
 Library/Homebrew/locale.rb                | 68 +++++++++++++++++++++
 2 files changed, 140 insertions(+)
 create mode 100644 Library/Homebrew/cask/spec/locale_spec.rb
 create mode 100644 Library/Homebrew/locale.rb

diff --git a/Library/Homebrew/cask/spec/locale_spec.rb b/Library/Homebrew/cask/spec/locale_spec.rb
new file mode 100644
index 0000000000000..98a2de9139469
--- /dev/null
+++ b/Library/Homebrew/cask/spec/locale_spec.rb
@@ -0,0 +1,72 @@
+require "spec_helper"
+require "locale"
+
+describe Locale do
+  describe "::parse" do
+    it "parses a string in the correct format" do
+      expect(described_class.parse("zh")).to eql(described_class.new("zh", nil, nil))
+      expect(described_class.parse("zh-CN")).to eql(described_class.new("zh", "CN", nil))
+      expect(described_class.parse("zh-Hans")).to eql(described_class.new("zh", nil, "Hans"))
+      expect(described_class.parse("zh-CN-Hans")).to eql(described_class.new("zh", "CN", "Hans"))
+    end
+
+    context "raises a ParserError when given" do
+      it "an empty string" do
+        expect{ described_class.parse("") }.to raise_error(Locale::ParserError)
+      end
+
+      it "a string in a wrong format" do
+        expect { described_class.parse("zh_CN_Hans") }.to raise_error(Locale::ParserError)
+        expect { described_class.parse("zhCNHans") }.to raise_error(Locale::ParserError)
+        expect { described_class.parse("zh-CN_Hans") }.to raise_error(Locale::ParserError)
+        expect { described_class.parse("zhCN") }.to raise_error(Locale::ParserError)
+        expect { described_class.parse("zh_Hans") }.to raise_error(Locale::ParserError)
+      end
+    end
+  end
+
+  describe "::new" do
+    it "raises an ArgumentError when all arguments are nil" do
+      expect { described_class.new(nil, nil, nil) }.to raise_error(ArgumentError)
+    end
+
+    it "raises a ParserError when one of the arguments does not match the locale format" do
+      expect { described_class.new("ZH", nil, nil) }.to raise_error(Locale::ParserError)
+      expect { described_class.new(nil, "cn", nil) }.to raise_error(Locale::ParserError)
+      expect { described_class.new(nil, nil, "hans") }.to raise_error(Locale::ParserError)
+    end
+  end
+
+  subject { described_class.new("zh", "CN", "Hans") }
+
+  describe "#include?" do
+    it { is_expected.to include("zh") }
+    it { is_expected.to include("zh-CN") }
+    it { is_expected.to include("CN") }
+    it { is_expected.to include("CN-Hans") }
+    it { is_expected.to include("Hans") }
+    it { is_expected.to include("zh-CN-Hans") }
+  end
+
+  describe "#eql?" do
+    subject { described_class.new("zh", "CN", "Hans") }
+
+    context "all parts match" do
+      it { is_expected.to eql("zh-CN-Hans") }
+      it { is_expected.to eql(subject) }
+    end
+
+    context "only some parts match" do
+      it { is_expected.to_not eql("zh") }
+      it { is_expected.to_not eql("zh-CN") }
+      it { is_expected.to_not eql("CN") }
+      it { is_expected.to_not eql("CN-Hans") }
+      it { is_expected.to_not eql("Hans") }
+    end
+
+    it "does not raise if 'other' cannot be parsed" do
+      expect { subject.eql?("zh_CN_Hans") }.not_to raise_error
+      expect(subject.eql?("zh_CN_Hans")).to be false
+    end
+  end
+end
diff --git a/Library/Homebrew/locale.rb b/Library/Homebrew/locale.rb
new file mode 100644
index 0000000000000..1aff33dae6c8b
--- /dev/null
+++ b/Library/Homebrew/locale.rb
@@ -0,0 +1,68 @@
+class Locale
+  class ParserError < ::RuntimeError
+  end
+
+  LANGUAGE_REGEX = /(?:[a-z]{2})/
+  REGION_REGEX = /(?:[A-Z]{2})/
+  SCRIPT_REGEX = /(?:[A-Z][a-z]{3})/
+
+  LOCALE_REGEX = /^(#{LANGUAGE_REGEX})?(?:(?:^|-)(#{REGION_REGEX}))?(?:(?:^|-)(#{SCRIPT_REGEX}))?$/
+
+  def self.parse(string)
+    language, region, script = string.to_s.scan(LOCALE_REGEX)[0]
+
+    if language.nil? && region.nil? && script.nil?
+      raise ParserError, "'#{string}' cannot be parsed to a #{self.class}"
+    end
+
+    new(language, region, script)
+  end
+
+  attr_reader :language, :region, :script
+
+  def initialize(language, region, script)
+    if language.nil? && region.nil? && script.nil?
+      raise ArgumentError, "#{self.class} cannot be empty"
+    end
+
+    {
+      language: language,
+      region:   region,
+      script:   script,
+    }.each do |key, value|
+      next if value.nil?
+
+      regex = self.class.const_get("#{key.upcase}_REGEX")
+      raise ParserError, "'#{value}' does not match #{regex}" unless value =~ regex
+      instance_variable_set(:"@#{key}", value)
+    end
+
+    self
+  end
+
+  def include?(other)
+    other = self.class.parse(other) unless other.is_a?(self.class)
+
+    [:language, :region, :script].all? { |var|
+      if other.public_send(var).nil?
+        true
+      else
+        public_send(var) == other.public_send(var)
+      end
+    }
+  end
+
+  def eql?(other)
+    other = self.class.parse(other) unless other.is_a?(self.class)
+    [:language, :region, :script].all? { |var|
+      public_send(var) == other.public_send(var)
+    }
+  rescue ParserError
+    false
+  end
+  alias == eql?
+
+  def to_s
+    [@language, @region, @script].compact.join("-")
+  end
+end

From 013f33be4488205dd1fdf4f1b798dac58d1b93fe Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Wed, 28 Sep 2016 00:48:19 +0200
Subject: [PATCH 12/15] Change language DSL to only allow strings.

---
 Library/Homebrew/cask/lib/hbc/dsl.rb        | 32 ++++-------
 Library/Homebrew/cask/test/cask/dsl_test.rb | 61 +++++++++++++--------
 2 files changed, 48 insertions(+), 45 deletions(-)

diff --git a/Library/Homebrew/cask/lib/hbc/dsl.rb b/Library/Homebrew/cask/lib/hbc/dsl.rb
index 9970f83954766..08afe75fc519f 100644
--- a/Library/Homebrew/cask/lib/hbc/dsl.rb
+++ b/Library/Homebrew/cask/lib/hbc/dsl.rb
@@ -1,4 +1,5 @@
 require "set"
+require "locale"
 
 require "hbc/dsl/appcast"
 require "hbc/dsl/base"
@@ -99,9 +100,10 @@ def homepage(homepage = nil)
       @homepage ||= homepage
     end
 
-    def language(*args, &block)
+    def language(*args, default: false, &block)
       if !args.empty? && block_given?
         @language_blocks ||= {}
+        @language_blocks.default = block if default
         @language_blocks[args] = block
       else
         language_eval
@@ -114,29 +116,15 @@ def language_eval
 
       return unless instance_variable_defined?(:@language_blocks)
 
-      default_key = @language_blocks.keys.detect { |key| key.include?(:default) }
+      MacOS.languages.map(&Locale.method(:parse)).any? { |locale|
+        key = @language_blocks.keys.detect { |strings|
+          strings.any? { |string| locale.include?(string) }
+        }
 
-      MacOS.languages.each do |language|
-        @language_blocks.each do |regexes_or_strings, block|
-          if regexes_or_strings.include?(:default)
-            regexes_or_strings = regexes_or_strings - [:default] + [%r{^en}]
-          end
+        return @language = @language_blocks[key].call unless key.nil?
+      }
 
-          regexes_or_strings.each do |regex_or_string|
-            if regex_or_string.class == language.class
-              next unless regex_or_string == language
-            else
-              next unless regex_or_string =~ language
-            end
-
-            @language = block.call
-            return
-          end
-        end
-      end
-
-      # fallback to :default
-      @language = default_key.nil? ? nil : @language_blocks[default_key].call
+      @language = @language_blocks.default.call
     end
 
     def url(*args, &block)
diff --git a/Library/Homebrew/cask/test/cask/dsl_test.rb b/Library/Homebrew/cask/test/cask/dsl_test.rb
index f6fca3d2d1b9e..053eae1e1dd11 100644
--- a/Library/Homebrew/cask/test/cask/dsl_test.rb
+++ b/Library/Homebrew/cask/test/cask/dsl_test.rb
@@ -124,36 +124,51 @@
 
   describe "language stanza" do
     it "allows multilingual casks" do
-      cask = lambda {
+      cask = lambda do
         Hbc::Cask.new("cask-with-apps") do
-          language "FIRST_LANGUAGE" do
-            :first
+          language "zh" do
+            sha256 "abc123"
+            "zh-CN"
           end
 
-          language %r{SECOND_LANGUAGE} do
-            :second
+          language "en-US", default: true do
+            sha256 "xyz789"
+            "en-US"
           end
 
-          language :default do
-            :default
-          end
+          url "https://example.org/#{language}.zip"
         end
-      }
-
-      MacOS.stubs(languages: ["FIRST_LANGUAGE"])
-      cask.call.language.must_equal :first
-
-      MacOS.stubs(languages: ["SECOND_LANGUAGE"])
-      cask.call.language.must_equal :second
-
-      MacOS.stubs(languages: ["THIRD_LANGUAGE"])
-      cask.call.language.must_equal :default
-
-      MacOS.stubs(languages: ["THIRD_LANGUAGE", "SECOND_LANGUAGE", "FIRST_LANGUAGE"])
-      cask.call.language.must_equal :second
+      end
 
-      MacOS.stubs(languages: ["THIRD_LANGUAGE", "FIRST_LANGUAGE", "SECOND_LANGUAGE"])
-      cask.call.language.must_equal :first
+      MacOS.stubs(languages: ["zh"])
+      cask.call.language.must_equal "zh-CN"
+      cask.call.sha256.must_equal "abc123"
+      cask.call.url.to_s.must_equal "https://example.org/zh-CN.zip"
+
+      MacOS.stubs(languages: ["zh-XX"])
+      cask.call.language.must_equal "zh-CN"
+      cask.call.sha256.must_equal "abc123"
+      cask.call.url.to_s.must_equal "https://example.org/zh-CN.zip"
+
+      MacOS.stubs(languages: ["en"])
+      cask.call.language.must_equal "en-US"
+      cask.call.sha256.must_equal "xyz789"
+      cask.call.url.to_s.must_equal "https://example.org/en-US.zip"
+
+      MacOS.stubs(languages: ["xx-XX"])
+      cask.call.language.must_equal "en-US"
+      cask.call.sha256.must_equal "xyz789"
+      cask.call.url.to_s.must_equal "https://example.org/en-US.zip"
+
+      MacOS.stubs(languages: ["xx-XX", "zh", "en"])
+      cask.call.language.must_equal "zh-CN"
+      cask.call.sha256.must_equal "abc123"
+      cask.call.url.to_s.must_equal "https://example.org/zh-CN.zip"
+
+      MacOS.stubs(languages: ["xx-XX", "en-US", "zh"])
+      cask.call.language.must_equal "en-US"
+      cask.call.sha256.must_equal "xyz789"
+      cask.call.url.to_s.must_equal "https://example.org/en-US.zip"
     end
   end
 

From b104e6ff37010232eacc86f442ef4d2cba155aac Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Wed, 28 Sep 2016 00:57:19 +0200
Subject: [PATCH 13/15] Raise error if more than one default language if
 specified.

---
 Library/Homebrew/cask/lib/hbc/dsl.rb | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/cask/lib/hbc/dsl.rb b/Library/Homebrew/cask/lib/hbc/dsl.rb
index 08afe75fc519f..a1129a21aeeb1 100644
--- a/Library/Homebrew/cask/lib/hbc/dsl.rb
+++ b/Library/Homebrew/cask/lib/hbc/dsl.rb
@@ -103,8 +103,15 @@ def homepage(homepage = nil)
     def language(*args, default: false, &block)
       if !args.empty? && block_given?
         @language_blocks ||= {}
-        @language_blocks.default = block if default
         @language_blocks[args] = block
+
+        return unless default
+
+        unless @language_blocks.default.nil?
+          raise CaskInvalidError.new(token, "Only one default language may be defined")
+        end
+
+        @language_blocks.default = block
       else
         language_eval
         @language

From ef26bf188254671127f9c6b11e1c76585f136629 Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Wed, 28 Sep 2016 02:22:25 +0200
Subject: [PATCH 14/15] Refactor audit for changed DSL.

---
 Library/Homebrew/cask/lib/hbc/auditor.rb | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/Library/Homebrew/cask/lib/hbc/auditor.rb b/Library/Homebrew/cask/lib/hbc/auditor.rb
index 7a6bb608fe9b3..ee1b50938b75b 100644
--- a/Library/Homebrew/cask/lib/hbc/auditor.rb
+++ b/Library/Homebrew/cask/lib/hbc/auditor.rb
@@ -4,10 +4,9 @@ def self.audit(cask, audit_download: false, check_token_conflicts: false)
       saved_languages = MacOS.instance_variable_get(:@languages)
 
       if languages_blocks = cask.instance_variable_get(:@dsl).instance_variable_get(:@language_blocks)
-        languages_blocks.keys.map(&:first).each do |language|
-          ohai "Auditing language #{language.to_s}"
-          language = "en-US" if language == :default
-          MacOS.instance_variable_set(:@languages, [language])
+        languages_blocks.keys.each do |languages|
+          ohai "Auditing language: #{languages.map { |lang| "'#{lang}'" }.join(", ")}"
+          MacOS.instance_variable_set(:@languages, languages)
           audit_cask_instance(Hbc.load(cask.sourcefile_path), audit_download, check_token_conflicts)
           CLI::Cleanup.run(cask.token) if audit_download
         end

From e2b3753fd91c47beeb3227a1c0df4c0dfa6026fc Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Mon, 3 Oct 2016 02:34:32 +0200
Subject: [PATCH 15/15] Style changes in `language_eval`.

---
 Library/Homebrew/cask/lib/hbc/dsl.rb | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/Library/Homebrew/cask/lib/hbc/dsl.rb b/Library/Homebrew/cask/lib/hbc/dsl.rb
index a1129a21aeeb1..8e0a7715af427 100644
--- a/Library/Homebrew/cask/lib/hbc/dsl.rb
+++ b/Library/Homebrew/cask/lib/hbc/dsl.rb
@@ -114,22 +114,25 @@ def language(*args, default: false, &block)
         @language_blocks.default = block
       else
         language_eval
-        @language
       end
     end
 
     def language_eval
-      return if instance_variable_defined?(:@language)
+      return @language if instance_variable_defined?(:@language)
 
-      return unless instance_variable_defined?(:@language_blocks)
+      if @language_blocks.nil? || @language_blocks.empty?
+        return @language = nil
+      end
 
-      MacOS.languages.map(&Locale.method(:parse)).any? { |locale|
+      MacOS.languages.map(&Locale.method(:parse)).each do |locale|
         key = @language_blocks.keys.detect { |strings|
           strings.any? { |string| locale.include?(string) }
         }
 
-        return @language = @language_blocks[key].call unless key.nil?
-      }
+        next if key.nil?
+
+        return @language = @language_blocks[key].call
+      end
 
       @language = @language_blocks.default.call
     end