Fix `relation.create` to avoid leaking scope to initialization block and callbacks

`relation.create` populates scope attributes to new record by `scoping`,
it is necessary to assign the scope attributes to the record and to find
STI subclass from the scope attributes.

But the effect of `scoping` is class global, it was caused undesired
behavior that pollute all class level querying methods in initialization
block and callbacks (`after_initialize`, `before_validation`,
`before_save`, etc), which are user provided code.

To avoid the leaking scope issue, restore the original current scope
before initialization block and callbacks are invoked.

Fixes #9894.
Fixes #17577.
Closes #31526.

1 files changed, 18 insertions, 3 deletions

diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index 6b5b877260..0ab0459c38 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -1167,7 +1167,12 @@ class RelationTest < ActiveRecord::TestCase
   end
 
   def test_first_or_create_with_block
-    parrot = Bird.where(color: "green").first_or_create { |bird| bird.name = "parrot" }
+    canary = Bird.create!(color: "yellow", name: "canary")
+    parrot = Bird.where(color: "green").first_or_create do |bird|
+      bird.name = "parrot"
+      assert_equal canary, Bird.find_by!(name: "canary")
+    end
+    assert_equal 1, parrot.total_count
     assert_kind_of Bird, parrot
     assert_predicate parrot, :persisted?
     assert_equal "green", parrot.color
@@ -1209,7 +1214,12 @@ class RelationTest < ActiveRecord::TestCase
   end
 
   def test_first_or_create_bang_with_valid_block
-    parrot = Bird.where(color: "green").first_or_create! { |bird| bird.name = "parrot" }
+    canary = Bird.create!(color: "yellow", name: "canary")
+    parrot = Bird.where(color: "green").first_or_create! do |bird|
+      bird.name = "parrot"
+      assert_equal canary, Bird.find_by!(name: "canary")
+    end
+    assert_equal 1, parrot.total_count
     assert_kind_of Bird, parrot
     assert_predicate parrot, :persisted?
     assert_equal "green", parrot.color
@@ -1259,7 +1269,12 @@ class RelationTest < ActiveRecord::TestCase
   end
 
   def test_first_or_initialize_with_block
-    parrot = Bird.where(color: "green").first_or_initialize { |bird| bird.name = "parrot" }
+    canary = Bird.create!(color: "yellow", name: "canary")
+    parrot = Bird.where(color: "green").first_or_initialize do |bird|
+      bird.name = "parrot"
+      assert_equal canary, Bird.find_by!(name: "canary")
+    end
+    assert_equal 1, parrot.total_count
     assert_kind_of Bird, parrot
     assert_not_predicate parrot, :persisted?
     assert_predicate parrot, :valid?