Mutation tracker should be cleared before continuing around callbacks

`changes_applied` should be called before continuing around callback
chain. Otherwise the mutation tracker returns old value for methods like
`changed`? or `id_in_database` in around callbacks. Also methods depend
on `id_in_database`, like `update_column`, are not working in
`around_create` callbacks.

```
class Foo < ActiveRecord::Base
  around_create :around_create_callback

  def around_create_callback
    ...
    yield
    p id_in_database # => nil
    update_column(:generated_column, generate_value) # silently fails
  end

  ...
end
```

1 files changed, 20 insertions, 0 deletions

diff --git a/activerecord/test/cases/dirty_test.rb b/activerecord/test/cases/dirty_test.rb
index 83cc2aa319..1f0e770a93 100644
--- a/activerecord/test/cases/dirty_test.rb
+++ b/activerecord/test/cases/dirty_test.rb
@@ -879,6 +879,26 @@ class DirtyTest < ActiveRecord::TestCase
         raise "changed? should be false" if changed?
         raise "has_changes_to_save? should be false" if has_changes_to_save?
         raise "saved_changes? should be true" unless saved_changes?
+        raise "id_in_database should not be nil" if id_in_database.nil?
+      end
+    end
+
+    person = klass.create!(first_name: "Sean")
+    assert_not_predicate person, :changed?
+  end
+
+  test "changed? in around callbacks after yield returns false" do
+    klass = Class.new(ActiveRecord::Base) do
+      self.table_name = "people"
+
+      around_create :check_around
+
+      def check_around
+        yield
+        raise "changed? should be false" if changed?
+        raise "has_changes_to_save? should be false" if has_changes_to_save?
+        raise "saved_changes? should be true" unless saved_changes?
+        raise "id_in_database should not be nil" if id_in_database.nil?
       end
     end