Teach M-x disassemble a default argument.

Adopts default argument in the same way as `describe-function'.
* lisp/emacs-lisp/disass.el (disassemble): Default to function at point,
if any.

1 files changed, 7 insertions, 3 deletions

diff --git a/lisp/emacs-lisp/disass.el b/lisp/emacs-lisp/disass.el
index e67b0220e14..8506ed69669 100644
--- a/lisp/emacs-lisp/disass.el
+++ b/lisp/emacs-lisp/disass.el
@@ -54,9 +54,13 @@ OBJECT can be a symbol defined as a function, or a function itself
 \(a lambda expression or a compiled-function object).
 If OBJECT is not already compiled, we compile it, but do not
 redefine OBJECT if it is a symbol."
-  (interactive (list (intern (completing-read "Disassemble function: "
-                                              obarray 'fboundp t))
-                     nil 0 t))
+  (interactive
+   (let* ((fn (function-called-at-point))
+          (prompt (if fn (format "Disassemble function (default %s): " fn)
+                    "Disassemble function: "))
+          (def (and fn (symbol-name fn))))
+     (list (intern (completing-read prompt obarray 'fboundp t nil nil def))
+           nil 0 t)))
   (if (and (consp object) (not (functionp object)))
       (setq object `(lambda () ,object)))
   (or indent (setq indent 0))           ;Default indent to zero