Handle RSpec description with japanese char in CP932 encoded files

When the user create a test with CP932 encoding and japanese chars RSpec
fail to properly display characters or crash with the error:

>  Encoding::CompatibilityError: incompatible character encodings: Windows-31J and UTF-8

Fix:
- #2570
- https://github.com/rspec/rspec-core/issues/2543

Author: benoittgt

lib/rspec/core/formatters/exception_presenter.rb

@@ -81,7 +81,7 @@ def fully_formatted(failure_number, colorizer=::RSpec::Core::Formatters::Console
 
         def fully_formatted_lines(failure_number, colorizer)
           lines = [
-            description,
+            encoded_description(description),
             detail_formatter.call(example, colorizer),
             formatted_message_and_backtrace(colorizer),
             extra_detail_formatter.call(failure_number, colorizer),
@@ -244,6 +244,10 @@ def formatted_message_and_backtrace(colorizer)
           end
         end
 
+        def encoded_description(description)
+          encoded_string(description) if description
+        end
+
         def exception_backtrace
           exception.backtrace || []
         end

spec/rspec/core/formatters/exception_presenter_spec.rb

@@ -94,6 +94,21 @@ module RSpec::Core
         EOS
       end
 
+      it 'allows the caller to add encoded description' do
+        the_presenter = Formatters::ExceptionPresenter.new(exception, example,
+                                                           :description => "ジ".encode("CP932"))
+
+        expect(the_presenter.fully_formatted(1)).to eq(<<-EOS.gsub(/^ +\|/, ''))
+          |
+          |  1) ジ
+          |     Failure/Error: # The failure happened here!#{ encoding_check }
+          |
+          |       Boom
+          |       Bam
+          |     # ./spec/rspec/core/formatters/exception_presenter_spec.rb:#{line_num}
+        EOS
+      end
+
       it 'allows the caller to omit the description' do
         the_presenter = Formatters::ExceptionPresenter.new(exception, example,
                                                        :detail_formatter => Proc.new { "Detail!" },