Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
- `app/controllers/statuses_controller.rb`:
  Minor conflict due to theming system

app/validators/reaction_validator.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class ReactionValidator < ActiveModel::Validator
+  SUPPORTED_EMOJIS = Oj.load(File.read(Rails.root.join('app', 'javascript', 'mastodon', 'features', 'emoji', 'emoji_map.json'))).keys.freeze
+
+  def validate(reaction)
+    return if reaction.name.blank? || reaction.custom_emoji_id.present?
+
+    reaction.errors.add(:name, I18n.t('reactions.errors.unrecognized_emoji')) unless unicode_emoji?(reaction.name)
+  end
+
+  private
+
+  def unicode_emoji?(name)
+    SUPPORTED_EMOJIS.include?(name)
+  end
+end