Call block to #redirect_to in controller context (#33735)

* Call block to #redirect_to in controller context

The documentation for ActionController::Redirecting states that a Proc
argument "will be executed in the controller's context."  However,
unless #instance_eval is used (removed in 6b3ad0ca), that statement is
false for procs defined outside of the controller instance.

This commit restores the documented behavior.

Fixes #33731.

* Move test proc into a constant in another class

Per @rafaelfranca's suggestion.

[Steven Peckins + Rafael Mendonça França]

actionpack/lib/action_controller/metal/redirecting.rb

@@ -105,7 +105,7 @@ module ActionController
       when String
         request.protocol + request.host_with_port + options
       when Proc
-        _compute_redirect_to_location request, options.call
+        _compute_redirect_to_location request, instance_eval(&options)
       else
         url_for(options)
       end.delete("\0\r\n")

actionpack/test/controller/redirect_test.rb

@@ -5,6 +5,12 @@ require "abstract_unit"
 class Workshop
   extend ActiveModel::Naming
   include ActiveModel::Conversion
+
+  OUT_OF_SCOPE_BLOCK = proc do
+    raise "Not executed in controller's context" unless RedirectController === self
+    request.original_url
+  end
+
   attr_accessor :id
 
   def initialize(id)
@@ -119,6 +125,10 @@ class RedirectController < ActionController::Base
     redirect_to proc { { action: "hello_world" } }
   end
 
+  def redirect_to_out_of_scope_block
+    redirect_to Workshop::OUT_OF_SCOPE_BLOCK
+  end
+
   def redirect_with_header_break
     redirect_to "/lol\r\nwat"
   end
@@ -326,6 +336,12 @@ class RedirectTest < ActionController::TestCase
     assert_redirected_to "http://www.rubyonrails.org/"
   end
 
+  def test_redirect_to_out_of_scope_block
+    get :redirect_to_out_of_scope_block
+    assert_response :redirect
+    assert_redirected_to "http://test.host/redirect/redirect_to_out_of_scope_block"
+  end
+
   def test_redirect_to_with_block_and_accepted_options
     with_routing do |set|
       set.draw do