Fix `tagged` param not being normalized before querying tags (#10249)

app/controllers/accounts_controller.rb

@@ -80,7 +80,13 @@ class AccountsController < ApplicationController
   end
 
   def hashtag_scope
-    Status.tagged_with(Tag.find_by(name: params[:tag].downcase)&.id)
+    tag = Tag.find_normalized(params[:tag])
+
+    if tag
+      Status.tagged_with(tag.id)
+    else
+      Status.none
+    end
   end
 
   def set_account

app/controllers/api/v1/accounts/statuses_controller.rb

@@ -69,7 +69,13 @@ class Api::V1::Accounts::StatusesController < Api::BaseController
   end
 
   def hashtag_scope
-    Status.tagged_with(Tag.find_by(name: params[:tagged])&.id)
+    tag = Tag.find_normalized(params[:tagged])
+
+    if tag
+      Status.tagged_with(tag.id)
+    else
+      Status.none
+    end
   end
 
   def pagination_params(core_params)

app/controllers/api/v1/timelines/tag_controller.rb

@@ -14,7 +14,7 @@ class Api::V1::Timelines::TagController < Api::BaseController
   private
 
   def load_tag
-    @tag = Tag.find_by(name: params[:id].downcase)
+    @tag = Tag.find_normalized(params[:id])
   end
 
   def load_statuses

app/controllers/tags_controller.rb

@@ -9,7 +9,7 @@ class TagsController < ApplicationController
   before_action :set_instance_presenter
 
   def show
-    @tag = Tag.find_by!(name: params[:id].downcase)
+    @tag = Tag.find_normalized!(params[:id])
 
     respond_to do |format|
       format.html do

app/models/tag.rb

@@ -72,6 +72,14 @@ class Tag < ApplicationRecord
          .limit(limit)
          .offset(offset)
     end
+
+    def find_normalized(name)
+      find_by(name: name.mb_chars.downcase.to_s)
+    end
+
+    def find_normalized!(name)
+      find_normalized(name) || raise(ActiveRecord::RecordNotFound)
+    end
   end
 
   private