Variable: diff-entire-buffers
diff-entire-buffers is a customizable variable defined in diff.el.gz.
Value
t
Documentation
If non-nil, diff the entire buffers, not just the visible part.
If nil, only use the narrowed-to parts of the buffers.
This variable was added, or its default value changed, in Emacs 29.1.
Source Code
;; Defined in /usr/src/emacs/lisp/vc/diff.el.gz
(defcustom diff-entire-buffers t
"If non-nil, diff the entire buffers, not just the visible part.
If nil, only use the narrowed-to parts of the buffers."
:type 'boolean
:version "29.1")