Variable: yank-undo-function
yank-undo-function is a variable defined in simple.el.gz.
Value
nil
Documentation
If non-nil, function used by yank-pop to delete last stretch of yanked text.
Function is called with two parameters, START and END corresponding to
the value of the mark and point; it is guaranteed that START <= END.
Normally set from the UNDO element of a yank-handler; see insert-for-yank.
Probably introduced at or before Emacs version 22.1.
Source Code
;; Defined in /usr/src/emacs/lisp/simple.el.gz
(defvar yank-undo-function nil
"If non-nil, function used by `yank-pop' to delete last stretch of yanked text.
Function is called with two parameters, START and END corresponding to
the value of the mark and point; it is guaranteed that START <= END.
Normally set from the UNDO element of a yank-handler; see `insert-for-yank'.")