Merge pull request #13166 from bogdan/transaction-magic

[Regression 3.2 -> 4.0] Fix bugs with changed attributes tracking when transaction gets rollback

2 files changed, 6 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index 4571cc0786..22870fb6c5 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -505,7 +505,6 @@ module ActiveRecord
       @destroyed_by_association = nil
       @new_record               = true
       @txn                      = nil
-      @_start_transaction_state = {}
       @transaction_state        = nil
       @reflects_state           = [false]
     end
diff --git a/activerecord/lib/active_record/transactions.rb b/activerecord/lib/active_record/transactions.rb
index 17f76b63b3..33c9af3d3d 100644
--- a/activerecord/lib/active_record/transactions.rb
+++ b/activerecord/lib/active_record/transactions.rb
@@ -341,6 +341,7 @@ module ActiveRecord
 
     # Save the new record state and id of a record so it can be restored later if a transaction fails.
     def remember_transaction_record_state #:nodoc:
+      @_start_transaction_state ||= {}
       @_start_transaction_state[:id] = id if has_attribute?(self.class.primary_key)
       unless @_start_transaction_state.include?(:new_record)
         @_start_transaction_state[:new_record] = @new_record
@@ -350,6 +351,8 @@ module ActiveRecord
       end
       @_start_transaction_state[:level] = (@_start_transaction_state[:level] || 0) + 1
       @_start_transaction_state[:frozen?] = @attributes.frozen?
+      @_start_transaction_state[:changed_attributes] ||= changed_attributes
+      @_start_transaction_state
     end
 
     # Clear the new record state and id of a record.
@@ -368,6 +371,9 @@ module ActiveRecord
           @attributes = @attributes.dup if @attributes.frozen?
           @new_record = restore_state[:new_record]
           @destroyed  = restore_state[:destroyed]
+          changed_attributes.replace(restore_state[:changed_attributes]).delete_if do |attribute, old_value|
+            old_value == @attributes[attribute]
+          end
           if restore_state.has_key?(:id)
             write_attribute(self.class.primary_key, restore_state[:id])
           else