introduce request_store to ensure that the current user doesn't leak across request boundaries (#16685)

Contributed by Holger Just.

git-svn-id: http://svn.redmine.org/redmine/trunk@13110 e93f8b46-1217-0410-a6f0-8f06a7374b81

Gemfile

@@ -6,6 +6,7 @@ gem "jquery-rails", "~> 2.0.2"
 gem "coderay", "~> 1.1.0"
 gem "fastercsv", "~> 1.5.0", :platforms => [:mri_18, :mingw_18, :jruby]
 gem "builder", "3.0.0"
+gem 'request_store'
 gem "mime-types"
 
 # Optional gem for LDAP authentication

app/models/user.rb

@@ -626,11 +626,11 @@ class User < Principal
   end
 
   def self.current=(user)
-    Thread.current[:current_user] = user
+    RequestStore.store[:current_user] = user
   end
 
   def self.current
-    Thread.current[:current_user] ||= User.anonymous
+    RequestStore.store[:current_user] ||= User.anonymous
   end
 
   # Returns the anonymous user.  If the anonymous user does not exist, it is created.  There can be only