Flymaking just deleted buffer throws exception

Flymaking just deleted buffer throws exception

[Johan Lindström]

I have flymake enabled for Perl. I open a file, then immediately kill
the buffer (while a flymake is run in the background).

This leads to the following error being displayed in the
echo area:

error in process filter: save-current-buffer: Selecting deleted buffer
error in process filter: Selecting deleted buffer


If I have "M-x toggle-debug-on-error", this stack trace is triggered:

Debugger entered--Lisp error: (error "Selecting deleted buffer")
   set-buffer(#<killed buffer>)
   (save-current-buffer (set-buffer source-buffer) 
(flymake-parse-output-and-residual output))
   (with-current-buffer source-buffer 
(flymake-parse-output-and-residual output))
   (progn (with-current-buffer source-buffer 
(flymake-parse-output-and-residual output)))
   (if source-buffer (progn (with-current-buffer source-buffer ...)))
   (when source-buffer (with-current-buffer source-buffer 
(flymake-parse-output-and-residual output)))
   (let ((source-buffer ...)) (flymake-log 3 "received %d byte(s) of 
output from process %d" (length output) (process-id process)) (when 
source-buffer (with-current-buffer source-buffer ...)))
   flymake-process-filter(#<process flymake-proc> "Terminating on 
signal SIGHUP(1)\n")


A buffer-live-p check before doing things to the buffer may be appropriate.

This is for flymake 0.3 which I believe is part of GNU Emacs nowadays 
(otherwise, sorry for the bug spam).


In GNU Emacs 22.0.990.1 (i386-mingw-nt5.1.2600)
  of 2007-05-23 on LENNART-69DE564 (patched)
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4) --cflags -Ic:/g/include'

Important settings:
   value of $LC_ALL: nil
   value of $LC_COLLATE: nil
   value of $LC_CTYPE: nil
   value of $LC_MESSAGES: nil
   value of $LC_MONETARY: nil
   value of $LC_NUMERIC: nil
   value of $LC_TIME: nil
   value of $LANG: SVE
   locale-coding-system: cp1252
   default-enable-multibyte-characters: t

Major mode: Emacs-Lisp

Minor modes in effect:
   highlight-changes-mode: passive
   shell-dirtrack-mode: t
   yas/minor-mode: t
   recentf-mode: t
   show-paren-mode: t
   delete-selection-mode: t
   pc-selection-mode: t
   savehist-mode: t
   encoded-kbd-mode: t
   tooltip-mode: t
   mouse-wheel-mode: t
   noticeable-minibuffer-prompts-mode: t
   menu-bar-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   blink-cursor-mode: t
   unify-8859-on-encoding-mode: t
   utf-translate-cjk-mode: t
   auto-compression-mode: t
   column-number-mode: t
   line-number-mode: t
   transient-mark-mode: t

Recent input:
C-x C-b C-g C-g C-x C-s C-x C-b C-g C-g C-g <C-tab>
C-x C-s C-x C-b <down> <down> <return> C-x o C-x b
<return> <down> <down> <down> <down> <down> C-x C-r
<down> <return> C-x k <return> C-x o <C-tab> C-s f
l y m a k <down> <down> <down> C-x o M-x r e p o r
t SPC SPC SPC SPC SPC <return> C-g <C-tab> <down> <down>
<down> <down> <up> <C-left> <C-left> <C-left> <C-left>
<C-left> <return> C-g C-x C-f C-g <up> <up> <down>
<down> M-x r e p o r t SPC SPC SPC SPC <return> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> C-h C-e C-s f l y m a k <up> <up>
<down> <C-home> C-s d e l e t e d SPC u <backspace>
b u SPC <up> C-x k <return> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <right> <right>
<return> C-c C-b C-h m <C-tab> <C-tab> b C-b <down>
<up> <down> <C-tab> C-s b a c k C-s <C-tab> l n l <C-tab>
<C-home> C-s l i n k C-s <C-home> C-s n o d e <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <up> <up> <up> <C-tab> <up> <up> <C-tab>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <up>
<up> <C-tab> <tab> <tab> <S-tab> <tab> <return> <down>
<down> C-x k <return> C-x C-g C-g <C-home> <S-down>
<S-down> <S-down> <S-down> <S-down> <up> <up> <down>
<down> <down> <down> <S-down> <C-insert> C-x C-b C-g
q M-x r e p r t <backspace> o r t SPC e m <backspace>
<backspace> SPC <backspace> SPC <backspace> <backspace>
<backspace> <backspace> o <backspace> p o SPC SPC e
<backspace> r t SPC e SPC SPC SPC SPC <backspace> <backspace>
<backspace> <backspace> <backspace> <return>

Recent messages:
Mark saved where search started [2 times]
Type C-x 4 C-o RET to restore the other window.
Mark set
call-interactively: Beginning of buffer
Mark saved where search started [3 times]
Quit
Mark set [2 times]
Help: ?;   Menu: mouse-3;   Show: v;   Mark: u,m,s,d;   Save/Delete: 
x;   Misc: g,~,%,t
Quit
Making completion list... [2 times]


/J

Re: Flymaking just deleted buffer throws exception

[Stefan Monnier]

> I have flymake enabled for Perl. I open a file, then immediately kill
> the buffer (while a flymake is run in the background).

> This leads to the following error being displayed in the
> echo area:

> error in process filter: save-current-buffer: Selecting deleted buffer
> error in process filter: Selecting deleted buffer
[...]
> A buffer-live-p check before doing things to the buffer may be appropriate.

Indeed, I've installed the patch below,


        Stefan


--- flymake.el.~1.54.~	2008-05-28 13:18:48.000000000 -0400
+++ flymake.el	2008-06-03 04:11:10.000000000 -0400
@@ -583,7 +583,7 @@
 
     (flymake-log 3 "received %d byte(s) of output from process %d"
                  (length output) (process-id process))
-    (when source-buffer
+    (when (buffer-live-p source-buffer)
       (with-current-buffer source-buffer
         (flymake-parse-output-and-residual output)))))