FIX: strip zero width spaces from topic title

lib/text_cleaner.rb

@@ -17,7 +17,8 @@ class TextCleaner
       remove_all_periods_from_the_end: SiteSetting.title_prettify,
       remove_extraneous_space: SiteSetting.title_prettify && SiteSetting.default_locale == "en",
       fixes_interior_spaces: true,
-      strip_whitespaces: true
+      strip_whitespaces: true,
+      strip_zero_width_spaces: true
     }
   end
 
@@ -47,6 +48,8 @@ class TextCleaner
     text = normalize_whitespaces(text)
     # Strip whitespaces
     text.strip! if opts[:strip_whitespaces]
+    # Strip zero width spaces
+    text.gsub!(/\u200b/, '') if opts[:strip_zero_width_spaces]
 
     text
   end

spec/components/text_cleaner_spec.rb

@@ -159,6 +159,11 @@ describe TextCleaner do
       expect(TextCleaner.clean_title(" \t Hello there \n ")).to eq("Hello there")
     end
 
+    it "strips zero width spaces" do
+      expect(TextCleaner.clean_title("Hello​ ​there")).to eq("Hello there")
+      expect(TextCleaner.clean_title("Hello​ ​there").length).to eq(11)
+    end
+
     context "title_prettify site setting is enabled" do
 
       before { SiteSetting.title_prettify = true }