FIX: Title prettify shoundn't downcase all non-ascii titles

lib/text_cleaner.rb

@@ -31,7 +31,7 @@ class TextCleaner
     # Replace ????? with a single ?
     text.gsub!(/\?+/, '?') if opts[:deduplicate_question_marks]
     # Replace all-caps text with regular case letters
-    text = text.mb_chars.downcase.to_s if opts[:replace_all_upper_case] && (text =~ /[A-Z]+/) && (text == text.upcase)
+    text = text.mb_chars.downcase.to_s if opts[:replace_all_upper_case] && (text == text.mb_chars.upcase)
     # Capitalize first letter, but only when entire first word is lowercase
     first, rest = text.split(' ', 2)
     if first && opts[:capitalize_first_letter] && first == first.mb_chars.downcase

spec/components/text_cleaner_spec.rb

@@ -191,6 +191,10 @@ describe TextCleaner do
         expect(TextCleaner.clean_title("INVESTIGAÇÃO POLÍTICA NA CÂMARA")).to eq("Investigação política na câmara")
       end
 
+      it "doesn't downcase text if only one word is upcase in a non-ascii alphabet" do
+        expect(TextCleaner.clean_title("«Эта неделя в EVE»")).to eq("«Эта неделя в EVE»")
+      end
+
       it "capitalizes first unicode letter" do
         expect(TextCleaner.clean_title("épico encontro")).to eq("Épico encontro")
       end