vcursor-compare-windows
vcursor-compare-windows is an interactive compiled Lisp function in `vcursor.el
'.
(vcursor-compare-windows &optional IGNORE-WHITESPACE)
Compare text in current window with text in window with vcursor.
Compares the text starting at point in the current window and at the
vcursor position in the other window, moving over text in each one as
far as they match.
A prefix argument, if any, means ignore changes in whitespace.
The variable `compare-windows-whitespace' controls how whitespace is skipped.
If `compare-ignore-case' is non-nil, changes in case are also ignored.