Remove unnecessary string encoding handling in the i18n simple backen…

…d which made the backend break on Ruby 1.9.

lib/i18n/backend/simple.rb

@@ -151,12 +151,7 @@ def pluralize(locale, entry, count)
         def interpolate(locale, string, values = {})
           return string unless string.is_a?(String)
 
-          if string.respond_to?(:force_encoding)
-            original_encoding = string.encoding
-            string.force_encoding(Encoding::BINARY)
-          end
-
-          result = string.gsub(MATCH) do
+          string.gsub(MATCH) do
             escaped, pattern, key = $1, $2, $2.to_sym
 
             if escaped
@@ -169,9 +164,6 @@ def interpolate(locale, string, values = {})
               values[key].to_s
             end
           end
-
-          result.force_encoding(original_encoding) if original_encoding
-          result
         end
 
         # Loads a single translations file by delegating to #load_rb or

test/simple_backend_test.rb

@@ -253,6 +253,32 @@ def test_interpolate_given_a_value_hash_interpolates_into_unicode_string
     assert_equal 'Häi David!', @backend.send(:interpolate, nil, 'Häi {{name}}!', :name => 'David')
   end
 
+  def test_interpolate_given_an_unicode_value_hash_interpolates_to_the_string
+    assert_equal 'Hi ゆきひろ!', @backend.send(:interpolate, nil, 'Hi {{name}}!', :name => 'ゆきひろ')
+  end
+
+  def test_interpolate_given_an_unicode_value_hash_interpolates_into_unicode_string
+    assert_equal 'こんにちは、ゆきひろさん!', @backend.send(:interpolate, nil, 'こんにちは、{{name}}さん!', :name => 'ゆきひろ')
+  end
+
+  if Kernel.const_defined?(:Encoding)
+    def test_interpolate_given_a_non_unicode_multibyte_value_hash_interpolates_into_a_string_with_the_same_encoding
+      assert_equal euc_jp('Hi ゆきひろ!'), @backend.send(:interpolate, nil, 'Hi {{name}}!', :name => euc_jp('ゆきひろ'))
+    end
+
+    def test_interpolate_given_an_unicode_value_hash_into_a_non_unicode_multibyte_string_raises_encoding_compatibility_error
+      assert_raises(Encoding::CompatibilityError) do
+        @backend.send(:interpolate, nil, euc_jp('こんにちは、{{name}}さん!'), :name => 'ゆきひろ')
+      end
+    end
+
+    def test_interpolate_given_a_non_unicode_multibyte_value_hash_into_an_unicode_string_raises_encoding_compatibility_error
+      assert_raises(Encoding::CompatibilityError) do
+        @backend.send(:interpolate, nil, 'こんにちは、{{name}}さん!', :name => euc_jp('ゆきひろ'))
+      end
+    end
+  end
+
   def test_interpolate_given_nil_as_a_string_returns_nil
     assert_nil @backend.send(:interpolate, nil, nil, :name => 'David')
   end
@@ -272,6 +298,12 @@ def test_interpolate_given_an_empty_values_hash_raises_missing_interpolation_arg
   def test_interpolate_given_a_string_containing_a_reserved_key_raises_reserved_interpolation_key
     assert_raises(I18n::ReservedInterpolationKey) { @backend.send(:interpolate, nil, '{{default}}', {:default => nil}) }
   end
+
+  private
+
+  def euc_jp(string)
+    string.encode!(Encoding::EUC_JP)
+  end
 end
 
 class I18nSimpleBackendLocalizeDateTest < Test::Unit::TestCase
@@ -533,4 +565,4 @@ def test_reload_translations_uninitializes_translations
     @backend.reload!
     assert_equal @backend.initialized?, false
   end
-end
+end