bug#19611: 25.0.50; Edebug eval expression broken

bug#19611: 25.0.50; Edebug eval expression broken

[stephen_leake]

When using edebug to debug an elisp function, 'e'
(edebug-eval-expression) does not eval the expression in the execution
environment.

First, create a file "~/debug-edebug.el" containing:

(defun sal-debug ()
  (interactive)
  (with-current-buffer (get-buffer-create "sal buffer")
    (message "current-buffer: %s" (current-buffer))))

Then, starting from emacs -Q:

(find-file "~/debug-edebug.el")

;; place cursor in function body
C-u C-M-x
M-x sal-debug

;; step until inside the "with-current-buffer"

e (current-buffer)

-> <buffer #debug-edebug.el> WRONG! should be <buffer sal buffer>




In GNU Emacs 25.0.50.4 (x86_64-w64-mingw32)
 of 2015-01-13 on TAKVER
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure PKG_CONFIG_PATH=/mingw64/lib/pkgconfig'

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY ACL GNUTLS LIBXML2 ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: cp1252

Major mode: Emacs-Lisp

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t

Recent messages:
Back to top level
#<buffer debug-edebug.el>

Breakpoint set in sal-debug
Go...
Break
Result: #<buffer sal buffer>

#<buffer debug-edebug.el>
Back to top level

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message dired format-spec
rfc822 mml mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util help-fns mail-prsvr mail-utils edebug cl-loaddefs cl-lib
help-mode easymenu debug time-date tooltip eldoc electric uniquify
ediff-hook vc-hooks lisp-float-type mwheel dos-w32 ls-lisp disp-table
w32-win w32-vars tool-bar dnd fontset image regexp-opt fringe
tabulated-list newcomment elisp-mode lisp-mode prog-mode register page
menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core frame cham georgian utf-8-lang misc-lang
vietnamese tibetan thai tai-viet lao korean japanese hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer nadvice
loaddefs button faces cus-face macroexp files text-properties overlay
sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process w32notify w32
multi-tty emacs)

Memory information:
((conses 16 84186 8149)
 (symbols 56 18754 0)
 (miscs 48 52 158)
 (strings 32 15111 4481)
 (string-bytes 1 398625)
 (vectors 16 10307)
 (vector-slots 8 387648 8937)
 (floats 8 65 125)
 (intervals 56 241 30)
 (buffers 976 15))

bug#19611: also broken on Debian stable

[Stephen Leake]

I've duplicated the problem on Debian stable, with Emacs master updated
today (git rev 21d1f8b85eec8fc1f87bb30398e449f6b20b6ecc).

-- 
-- Stephe

bug#19611: 25.0.50; Edebug eval expression broken

[Andreas Politz]

This behaviour was introduced in this commit:

commit 6194477a622ce9293162d16a7ba98c9cfc18d124
Author: Stefan Monnier <monnier@iro.umontreal.ca>
Date:   Thu Dec 4 14:16:59 2014 -0500

    * src/eval.c (backtrace_eval_unrewind): Rewind also the excursions.
    (Fapply): Try and simplify the control flow.



-ap

bug#19611: 25.0.50; Edebug eval expression broken

[Dmitry Gutov]

I'm also seeing this problem.

bug#19611: 25.0.50; Edebug eval expression broken

[Stefan Monnier]

> I'm also seeing this problem.

I think the patch below fixes the problem.  Can you confirm?


        Stefan


diff --git a/lisp/emacs-lisp/edebug.el b/lisp/emacs-lisp/edebug.el
index 7faa101..1091877 100644
--- a/lisp/emacs-lisp/edebug.el
+++ b/lisp/emacs-lisp/edebug.el
@@ -2358,6 +2358,12 @@ MSG is printed after `::::} '."
 (defalias 'edebug-mark-marker 'mark-marker)
 
 (defun edebug--display (value offset-index arg-mode)
+  ;; edebug--display-1 is too big, we should split it.  This function
+  ;; here was just introduced to avoid making edebug--display-1
+  ;; yet a bit deeper.
+  (save-excursion (edebug--display-1 value offset-index arg-mode)))
+
+(defun edebug--display-1 (value offset-index arg-mode)
   (unless (marker-position edebug-def-mark)
     ;; The buffer holding the source has been killed.
     ;; Let's at least show a backtrace so the user can figure out
@@ -3317,6 +3323,9 @@ Return the result of the last expression."
      ;; Restore outside context.
      (setq-default cursor-in-non-selected-windows edebug-outside-d-c-i-n-s-w)
      (unwind-protect
+         ;; FIXME: This restoring of edebug-outside-buffer and
+         ;; edebug-outside-point is redundant now that backtrace-eval does it
+         ;; for us.
          (with-current-buffer edebug-outside-buffer ; of edebug-buffer
            (goto-char edebug-outside-point)
            (if (marker-buffer (edebug-mark-marker))

bug#19611: 25.0.50; Edebug eval expression broken

[Stefan Monnier]

> I think the patch below fixes the problem.  Can you confirm?

Installed,


        Stefan

bug#19611: 25.0.50; Edebug eval expression broken

[Dmitry Gutov]

On 02/25/2015 06:56 AM, Stefan Monnier wrote:

> I think the patch below fixes the problem.  Can you confirm?

Yep, works fine now. Thanks!

bug#19611: 25.0.50; Edebug eval expression broken

[Stephen Leake]

Dmitry Gutov <dgutov@yandex.ru> writes:

> On 02/25/2015 06:56 AM, Stefan Monnier wrote:
>
>> I think the patch below fixes the problem.  Can you confirm?
>
> Yep, works fine now. Thanks!

Works for me also.

Thanks,

-- 
-- Stephe