Fix issue with disabled subtrees and pluralization for KeyValue backend

lib/i18n/backend/base.rb

@@ -34,17 +34,17 @@ def translate(locale, key, options = {})
           entry = resolve(locale, key, entry, options)
         end
 
+        entry = entry.dup if entry.is_a?(String)
+
+        count = options[:count]
+        entry = pluralize(locale, entry, count) if count
+
         if entry.nil?
           if (options.key?(:default) && !options[:default].nil?) || !options.key?(:default)
             throw(:exception, I18n::MissingTranslation.new(locale, key, options))
           end
         end
 
-        entry = entry.dup if entry.is_a?(String)
-
-        count = options[:count]
-        entry = pluralize(locale, entry, count) if count
-
         deep_interpolation = options[:deep_interpolation]
         values = options.except(*RESERVED_KEYS)
         if values

lib/i18n/backend/key_value.rb

@@ -107,7 +107,51 @@ def lookup(locale, key, scope = [], options = {})
           key   = normalize_flat_keys(locale, key, scope, options[:separator])
           value = @store["#{locale}.#{key}"]
           value = JSON.decode(value) if value
-          value.is_a?(Hash) ? value.deep_symbolize_keys : value
+
+          if value.is_a?(Hash)
+            value.deep_symbolize_keys
+          elsif !value.nil?
+            value
+          elsif !@subtrees
+            SubtreeProxy.new("#{locale}.#{key}", @store)
+          end
+        end
+      end
+
+      class SubtreeProxy
+        def initialize(master_key, store)
+          @master_key = master_key
+          @store = store
+          @subtree = nil
+        end
+
+        def has_key?(key)
+          @subtree && @subtree.has_key?(key) || self[key]
+        end
+
+        def [](key)
+          unless @subtree && value = @subtree[key]
+            value = @store["#{@master_key}.#{key}"]
+            (@subtree ||= {})[key] = JSON.decode(value) if value
+          end
+          value
+        end
+
+        def is_a?(klass)
+          Hash == klass || super
+        end
+        alias :kind_of? :is_a?
+
+        def instance_of?(klass)
+          Hash == klass || super
+        end
+
+        def nil?
+          @subtree.nil?
+        end
+
+        def inspect
+          @subtree.inspect
         end
       end
 

test/backend/key_value_test.rb

@@ -40,4 +40,10 @@ def assert_flattens(expected, nested, escape=true, subtree=true)
       I18n.t("foo", :raise => true)
     end
   end
+
+  test "translate handles subtrees for pluralization" do
+    setup_backend!(false)
+    store_translations(:en, :bar => { :one => "One" })
+    assert_equal("One", I18n.t("bar", :count => 1))
+  end
 end if I18n::TestCase.key_value?