(debug-on-entry-1): Reimplement to make sure that debug-entry-code can

be safely removed from a function while this code is being evaluated.
Revert the 2005-02-27 change as the new implementation no longer
requires it.  Make sure that a function body containing just a string
is not mistaken for a docstring.

1 files changed, 10 insertions, 17 deletions

diff --git a/lisp/emacs-lisp/debug.el b/lisp/emacs-lisp/debug.el
index 06efa93f33f..fe642a276e8 100644
--- a/lisp/emacs-lisp/debug.el
+++ b/lisp/emacs-lisp/debug.el
@@ -25,7 +25,7 @@
 
 ;;; Commentary:
 
-;; This is a major mode documented in the Emacs manual.
+;; This is a major mode documented in the Emacs Lisp manual.
 
 ;;; Code:
 
@@ -479,8 +479,6 @@ Applies to the frame whose line point is on in the backtrace."
         (insert ? )))
   (beginning-of-line))
 
-
-
 (put 'debugger-env-macro 'lisp-indent-function 0)
 (defmacro debugger-env-macro (&rest body)
   "Run BODY in original environment."
@@ -694,7 +692,6 @@ If argument is nil or an empty string, cancel for all functions."
               (setq body (cons (documentation function) body)))
           (fset function (cons 'lambda (cons (car contents) body)))))))
 
-
 (defconst debug-entry-code '(if inhibit-debug-on-entry nil (debug 'debug))
   "Code added to a function to cause it to call the debugger upon entry.")
 
@@ -705,22 +702,18 @@ If argument is nil or an empty string, cancel for all functions."
         (debug-on-entry-1 function (cdr defn) flag)
       (or (eq (car defn) 'lambda)
           (error "%s not user-defined Lisp function" function))
-      (let ((tail (cddr defn)))
+      (let ((tail (cdr defn)))
         ;; Skip the docstring.
-        (if (stringp (car tail)) (setq tail (cdr tail)))
+        (when (and (stringp (cadr tail)) (cddr tail))
+          (setq tail (cdr tail)))
         ;; Skip the interactive form.
-        (if (eq 'interactive (car-safe (car tail))) (setq tail (cdr tail)))
-        (unless (eq flag (equal (car tail) debug-entry-code))
-          ;; If the function has no body, add nil as a body element.
-          (when (null tail)
-            (setq tail (list nil))
-            (nconc defn tail))
+        (when (eq 'interactive (car-safe (cadr tail))) 
+          (setq tail (cdr tail)))
+        (unless (eq flag (equal (cadr tail) debug-entry-code))
           ;; Add/remove debug statement as needed.
-          (if (not flag)
-              (progn (setcar tail (cadr tail))
-                     (setcdr tail (cddr tail)))
-            (setcdr tail (cons (car tail) (cdr tail)))
-            (setcar tail debug-entry-code)))
+          (if flag
+              (setcdr tail (cons debug-entry-code (cdr tail)))
+            (setcdr tail (cddr tail))))
         defn))))
 
 (defun debugger-list-functions ()