Merge pull request #3023 from Tho85/preserve_sti_type

AR::Base.becomes should not change the STI type

Conflicts:
	activerecord/CHANGELOG.md

1 files changed, 12 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index 8e749772a1..45f5406cc3 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -155,7 +155,18 @@ module ActiveRecord
       became.instance_variable_set("@new_record", new_record?)
       became.instance_variable_set("@destroyed", destroyed?)
       became.instance_variable_set("@errors", errors)
-      became.public_send("#{klass.inheritance_column}=", klass.name) unless self.class.descends_from_active_record?
+      became
+    end
+
+    # Wrapper around +becomes+ that also changes the instance's sti column value.
+    # This is especially useful if you want to persist the changed class in your
+    # database.
+    #
+    # Note: The old instance's sti column value will be changed too, as both objects
+    # share the same set of attributes.
+    def becomes!(klass)
+      became = becomes(klass)
+      became.public_send("#{klass.inheritance_column}=", klass.sti_name) unless self.class.descends_from_active_record?
       became
     end