Merge pull request #11424 from kennyj/fix_column_defaults_caching

Reset @column_defaults when assigning locking_column.

3 files changed, 15 insertions, 0 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 1eb2f2d130..404443f4ad 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,16 @@
+*   Reset @column_defaults when assigning `locking_column`.
+    We had a potential problem. For example:
+
+    class Post < ActiveRecord::Base
+      self.column_defaults  # if we call this unintentionally before setting locking_column ...
+      self.locking_column = 'my_locking_column'
+    end
+
+    Post.column_defaults["my_locking_column"]
+    => nil # expected value is 0 !
+
+    *kennyj*
+
 *   Remove extra select and update queries on save/touch/destroy ActiveRecord model
     with belongs to reflection with option `touch: true`.
 
diff --git a/activerecord/lib/active_record/locking/optimistic.rb b/activerecord/lib/active_record/locking/optimistic.rb
index 209de78898..2a7996c4e7 100644
--- a/activerecord/lib/active_record/locking/optimistic.rb
+++ b/activerecord/lib/active_record/locking/optimistic.rb
@@ -138,6 +138,7 @@ module ActiveRecord
 
         # Set the column to use for optimistic locking. Defaults to +lock_version+.
         def locking_column=(value)
+          @column_defaults = nil
           @locking_column = value.to_s
         end
 
diff --git a/activerecord/test/cases/locking_test.rb b/activerecord/test/cases/locking_test.rb
index 827fcf3d50..db7d3b80ab 100644
--- a/activerecord/test/cases/locking_test.rb
+++ b/activerecord/test/cases/locking_test.rb
@@ -17,6 +17,7 @@ class LockWithoutDefault < ActiveRecord::Base; end
 
 class LockWithCustomColumnWithoutDefault < ActiveRecord::Base
   self.table_name = :lock_without_defaults_cust
+  self.column_defaults # to test @column_defaults caching.
   self.locking_column = :custom_lock_version
 end