FIX: do not treat :: as a valid emoji

lib/validators/max_emojis_validator.rb

@@ -1,7 +1,7 @@
 class MaxEmojisValidator < ActiveModel::EachValidator
 
   def validate_each(record, attribute, value)
-    if Emoji.unicode_unescape(value).scan(/:([\w\-+]*(?::t\d)?):/).size > SiteSetting.max_emojis_in_title
+    if Emoji.unicode_unescape(value).scan(/:([\w\-+]+(?::t\d)?):/).size > SiteSetting.max_emojis_in_title
       record.errors.add(
         attribute, :max_emojis,
         max_emojis_count: SiteSetting.max_emojis_in_title

spec/components/validators/max_emojis_validator_spec.rb

@@ -17,6 +17,10 @@ describe MaxEmojisValidator do
       record.title = '🧐 Lots of emojis here 🎃 :joy: :sunglasses:'
       validate
       expect(record.errors[:title][0]).to eq(I18n.t("errors.messages.max_emojis", max_emojis_count: 3))
+
+      record.title = ':joy: :blush: :smile: is not only about emojis: Happyness::start()'
+      validate
+      expect(record.valid?).to be true
     end
   end