Case-insensitive search by usernames

app/controllers/accounts_controller.rb

@@ -29,7 +29,7 @@ class AccountsController < ApplicationController
   private
 
   def set_account
-    @account = Account.find_by!(username: params[:username], domain: nil)
+    @account = Account.find_local!(params[:username])
   end
 
   def set_webfinger_header

app/controllers/stream_entries_controller.rb

@@ -16,7 +16,7 @@ class StreamEntriesController < ApplicationController
   private
 
   def set_account
-    @account = Account.find_by!(username: params[:account_username], domain: nil)
+    @account = Account.find_local!(params[:account_username])
   end
 
   def set_stream_entry

app/models/account.rb

@@ -96,8 +96,12 @@ class Account < ApplicationRecord
   end
 
   def self.find_local!(username)
+    self.find_remote!(username, nil)
+  end
+
+  def self.find_remote!(username, domain)
     table = self.arel_table
-    self.where(table[:username].matches(username)).where(domain: nil).take!
+    self.where(table[:username].matches(username)).where(domain: domain).take!
   end
 
   def self.find_local(username)
@@ -106,6 +110,12 @@ class Account < ApplicationRecord
     nil
   end
 
+  def self.find_remote(username, domain)
+    self.find_remote!(username, domain)
+  rescue ActiveRecord::RecordNotFound
+    nil
+  end
+
   before_create do
     if local?
       keypair = OpenSSL::PKey::RSA.new(Rails.env.test? ? 1024 : 2048)

app/services/process_mentions_service.rb

@@ -8,7 +8,7 @@ class ProcessMentionsService < BaseService
 
     status.text.scan(Account::MENTION_RE).each do |match|
       username, domain  = match.first.split('@')
-      mentioned_account = Account.find_by(username: username, domain: domain)
+      mentioned_account = Account.find_remote(username, domain)
 
       if mentioned_account.nil? && !domain.nil?
         mentioned_account = follow_remote_account_service.("#{match.first}")