(inhibit-debug-on-entry): New var.

(debug): Use it.  Move the inhibit-trace earlier.
(debug-entry-code): New const.
(debug-on-entry-1): Use it.

1 files changed, 11 insertions, 4 deletions

diff --git a/lisp/emacs-lisp/debug.el b/lisp/emacs-lisp/debug.el
index 58fb3b4a1b8..06efa93f33f 100644
--- a/lisp/emacs-lisp/debug.el
+++ b/lisp/emacs-lisp/debug.el
@@ -93,6 +93,8 @@ This is to optimize `debugger-make-xrefs'.")
 (defvar debugger-outer-inhibit-redisplay)
 (defvar debugger-outer-cursor-in-echo-area)
 
+(defvar inhibit-debug-on-entry nil)
+
 ;;;###autoload
 (setq debugger 'debug)
 ;;;###autoload
@@ -147,6 +149,8 @@ first will be printed into the backtrace buffer."
       (setq overriding-terminal-local-map nil)
       ;; Don't let these magic variables affect the debugger itself.
       (let ((last-command nil) this-command track-mouse
+            (inhibit-trace t)
+            (inhibit-debug-on-entry t)
             unread-command-events
             unread-post-input-method-events
             last-input-event last-command-event last-nonmenu-event
@@ -189,8 +193,7 @@ first will be printed into the backtrace buffer."
                     (backtrace-debug 3 t))
                 (debugger-reenable)
                 (message "")
-                (let ((inhibit-trace t)
-                      (standard-output nil)
+                (let ((standard-output nil)
                       (buffer-read-only t))
                   (message "")
                   ;; Make sure we unbind buffer-read-only in the right buffer.
@@ -691,6 +694,10 @@ 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.")
+
 (defun debug-on-entry-1 (function defn flag)
   (if (subrp defn)
       (error "%s is a built-in function" function)
@@ -703,7 +710,7 @@ If argument is nil or an empty string, cancel for all functions."
         (if (stringp (car 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 'debug)))
+        (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))
@@ -713,7 +720,7 @@ If argument is nil or an empty string, cancel for all functions."
               (progn (setcar tail (cadr tail))
                      (setcdr tail (cddr tail)))
             (setcdr tail (cons (car tail) (cdr tail)))
-            (setcar tail '(debug 'debug))))
+            (setcar tail debug-entry-code)))
         defn))))
 
 (defun debugger-list-functions ()