allout-post-undo-hook is a variable defined in `allout.el'.
Its value is

  • This variable may be risky if used as a file-local variable.

Normal hook run after undo activity.
The item that's current when the hook is run *may* be the one
that was affected by the undo..

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.3 of Emacs.