Ensure aliased attributes passed to select are quoted if using from

Fixes #21488

[Sean Griffin & johanlunds]

activerecord/CHANGELOG.md

@@ -1,3 +1,9 @@
+*   Ensure `select` quotes aliased attributes, even when using `from`.
+
+    Fixes #21488
+
+    *Sean Griffin & @johanlunds*
+
 *   MySQL: support `unsigned` numeric data types.
 
     Example:

activerecord/lib/active_record/relation/query_methods.rb

@@ -250,7 +250,7 @@ module ActiveRecord
     def _select!(*fields) # :nodoc:
       fields.flatten!
       fields.map! do |field|
-        klass.attribute_alias?(field) ? klass.attribute_alias(field) : field
+        klass.attribute_alias?(field) ? klass.attribute_alias(field).to_sym : field
       end
       self.select_values += fields
       self

activerecord/test/cases/relations_test.rb

@@ -1897,4 +1897,14 @@ class RelationTest < ActiveRecord::TestCase
   def test_relation_join_method
     assert_equal 'Thank you for the welcome,Thank you again for the welcome', Post.first.comments.join(",")
   end
+
+  def test_selecting_aliased_attribute_quotes_column_name_when_from_is_used
+    klass = Class.new(ActiveRecord::Base) do
+      self.table_name = :test_with_keyword_column_name
+      alias_attribute :description, :desc
+    end
+    klass.create!(description: "foo")
+
+    assert_equal ["foo"], klass.select(:description).from(klass.all).map(&:desc)
+  end
 end

activerecord/test/schema/schema.rb

@@ -943,6 +943,10 @@ ActiveRecord::Schema.define do
     t.string :token
     t.string :auth_token
   end
+
+  create_table :test_with_keyword_column_name, force: true do |t|
+    t.string :desc
+  end
 end
 
 Course.connection.create_table :courses, force: true do |t|