Make sure that a MissingInterpolationArgument in the english locale is raised

lib/i18n_interpolation_fallbacks.rb

@@ -17,7 +17,7 @@ module I18n
         options.delete(:fallback)
 
         return super(locale, nil, options.merge(:default => default)) if default
-        raise(I18n::MissingInterpolationError.new(locale, key, options))
+        raise(I18n::MissingInterpolationArgument.new(options, "key: #{key} in locale: #{locale}"))
       end
     end
   end

spec/misc_spec.rb

@@ -75,6 +75,14 @@ describe 'making sure the spec runner works' do
       translation = translate('bob', :hey => "what")
       translation.should == "English translation"
     end
+    it 'MissingInterpolationError with no fallback is fatal' do
+      I18n.backend.stub!(:lookup).
+        with(:en, 'bob', nil, :hey => "what", :fallback => true).
+        and_return("English translation %{that_will_fail}")
+      lambda {
+        translate('bob', :hey => "what")
+      }.should raise_error I18n::MissingInterpolationArgument
+    end
   end
 
 end