Variable: buffers-menu-buffer-name-length
buffers-menu-buffer-name-length is a customizable variable defined in
menu-bar.el.gz.
Value
30
Documentation
Maximum length of the buffer name on the Buffers menu.
If this is a number, then buffer names are truncated to this length. If this is nil, then buffer names are shown in full. A large number or nil makes the menu too wide.
Source Code
;; Defined in /usr/src/emacs/lisp/menu-bar.el.gz
(defcustom buffers-menu-buffer-name-length 30
"Maximum length of the buffer name on the Buffers menu.
If this is a number, then buffer names are truncated to this length.
If this is nil, then buffer names are shown in full.
A large number or nil makes the menu too wide."
:type '(choice integer
(const :tag "Full length" nil))
:group 'menu)