What's up with the semi-permanent vc breakage?

What's up with the semi-permanent vc breakage?

[David Kastrup]

Hi,

usually the state in the trunk is supposed to be code that more or less
works.  With VC, this has not been true for at least several weeks:
there are problems with some "menu-filter" thing bombing out (at least
when debug-on-error is set) for operations as simple as C-v c =, and now
an uninitialized variable vc-client-mode (presumably from
vc-dispatcher.el) breaks operations when debug-on-error is set.

It is not really a solution for me to switch off debug-on-error
permanently (since that makes it, say, impossible to debug errors), and
it is not clear to me why unsetting it stops vc errors from occuring.

I remember some messages about expecting rough times ahead, and also
reports about this problem.  But there has been quiescence lately with
regard to mails on the list or checkins in the code.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum

Re: What's up with the semi-permanent vc breakage?

[Stefan Monnier]

> when debug-on-error is set) for operations as simple as C-v c =, and now
> an uninitialized variable vc-client-mode (presumably from
> vc-dispatcher.el) breaks operations when debug-on-error is set.

Hmm... so the bug's still there?  By the time I got to look into it,
I couldn't reproduce it, so I assumed it was fixed.  I use VC daily and
I have debug-on-error set, so the obvious problems get fixed quickly,
normally.
Could you give a detailed recipe to reproduce the problem.


        Stefan

Re: What's up with the semi-permanent vc breakage?

[David Kastrup]

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Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> when debug-on-error is set) for operations as simple as C-v c =, and now
>> an uninitialized variable vc-client-mode (presumably from
>> vc-dispatcher.el) breaks operations when debug-on-error is set.
>
> Hmm... so the bug's still there?  By the time I got to look into it,
> I couldn't reproduce it, so I assumed it was fixed.  I use VC daily and
> I have debug-on-error set, so the obvious problems get fixed quickly,
> normally.
> Could you give a detailed recipe to reproduce the problem.

I have to say I am surprised since it is not actually hard to reproduce.
In fact, the most simple-minded recipe triggers it.

dak@lola:~$ mkdir /tmp/zap
dak@lola:~$ cd /tmp/zap
dak@lola:/tmp/zap$ git init
Initialized empty Git repository in .git/
dak@lola:/tmp/zap$ echo x > y
dak@lola:/tmp/zap$ git add y
dak@lola:/tmp/zap$ git commit -m "1" y
Created initial commit ddfb366: 1
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 y
dak@lola:/tmp/zap$ echo x >> y
dak@lola:/tmp/zap$ git commit -m "2" y
Created commit fd5a91b: 2
 1 files changed, 1 insertions(+), 0 deletions(-)
dak@lola:/tmp/zap$ /usr/local/emacs-21/bin/emacs -Q -eval '(setq debug-on-error t)' x

C-x v =

Debugger entered--Lisp error: (void-variable vc-client-mode)
  vc-dir-menu-map-filter((keymap (open menu-item "Open file" vc-dir-find-file :help "Find the file on the current line") (open-other menu-item "Open in other window" vc-dir-find-file-other-window :help "Find the file on the current line, in another window") (sepopn "--") (mark menu-item "Mark" vc-dir-mark :help "Mark the current file or all files in the region") (unmark menu-item "Unmark" vc-dir-unmark :help "Unmark the current file or all files in the region") (mark-all menu-item "Mark All" vc-dir-mark-all-files :help "Mark all files that are in the same state as the current file\nWith prefix argument mark all files") (unmark-previous menu-item "Unmark previous " vc-dir-unmark-file-up :help "Move to the previous line and unmark the file") (unmark-all menu-item "Unmark All" vc-dir-unmark-all-files :help "Unmark all files that are in the same state as the current file\nWith prefix argument unmark all files") (sepmrk "--") (previous-line menu-item "Previous line" vc-dir-previous-line :help "Go to the previous line") (next-line menu-item "Next line" vc-dir-next-line :help "Go to the next line" :keys "n") (sepmv "--") (refresh menu-item "Refresh" vc-dir-refresh :enable (not ...) :help "Refresh the contents of the directory buffer") (kill menu-item "Kill Update Command" vc-dir-kill-dir-status-process :enable (vc-dir-busy) :help "Kill the command that updates the directory buffer") (quit menu-item "Quit" quit-window :help "Quit") "VC-dir"))
  where-is-internal(vc-dir-find-file (keymap (vc-dir-mode menu-item "VC-dir" (keymap ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... "VC-dir") :filter vc-dir-menu-map-filter)))
  tool-bar-local-item-from-menu(vc-dir-find-file "open" (keymap) (keymap #^[nil nil keymap #^^[3 0 nil nil nil ... nil nil nil nil nil vc-dir-next-directory nil nil nil vc-dir-find-file nil nil nil nil nil nil nil nil nil nil nil nil nil ... nil nil nil nil vc-dir-next-line nil nil nil nil nil nil nil nil nil nil nil nil negative-argument nil nil ...] #^^[1 0 #^^[2 0 #^^[3 0 nil nil nil ... nil nil nil nil nil vc-dir-next-directory nil nil nil vc-dir-find-file nil nil nil nil nil nil nil nil nil nil nil nil nil ... nil nil nil nil vc-dir-next-line nil nil nil nil nil nil nil nil nil nil nil nil negative-argument nil nil ...] nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil] nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil] nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil ...] (menu-bar keymap (vc-dir-mode menu-item "VC-dir" ... :filter vc-dir-menu-map-filter)) (mouse-2 . vc-dir-toggle-mark) (down-mouse-3 . vc-dir-menu) (C-up . vc-dir-previous-directory) (C-down . vc-dir-next-directory) (backtab . vc-dir-previous-directory) (remap keymap (self-insert-command . undefined))))
  byte-code("Ã\bB\x10ÄÃ!„Z\0ÅÃÆ \x19ÇÈÉ	\n$ˆÊË̉	ÍÎ&\x06ˆÇÏÐ	\nÑÒ&\x06ˆÇÓÒ	\nÑÐ&\x06ˆÇÔÕ	\n$ˆÇÖ×	\n$ˆÇØÙ	#ˆÇÚÛ	\n$ˆÇÜÝ	\n$ˆ	)\"ˆÃ‡" [current-load-list map vc-dir-mode-map vc-dir-tool-bar-map default-boundp set-default make-sparse-keymap tool-bar-local-item-from-menu vc-dir-find-file "open" tool-bar-local-item "bookmark_add" vc-dir-toggle-mark :help "Toggle mark on current item" vc-dir-previous-line "left-arrow" :rtl "right-arrow" vc-dir-next-line vc-print-log "info" vc-dir-refresh "refresh" nonincremental-search-forward "search" vc-dir-kill-dir-status-process "cancel" quit-window "exit"] 9)
  require(vc-dispatcher)
  byte-code("ÁÂ!ˆÁÃ!ˆÁÄ!ˆÁÅ!ˆÆÇ\b\"„^[\0È\bB\x10ÉÊËÌÍÎ%‡" [minor-mode-alist require vc-hooks vc-dispatcher tool-bar ewoc assoc vc-parent-buffer (vc-parent-buffer vc-parent-buffer-name) custom-declare-group vc nil "Version-control system in Emacs." :group tools] 6)



So here is some detail that might be worth mentioning: in my .Xdefaults
I have

Emacs.Geometry:80x35
Emacs.toolBar: 0
Emacs.Background: white
Emacs.font: -*-fixed-*-*-*-*-20-*-*-*-*-*-iso10646-*

In particular, switching off the toolbar might or might not be relevant.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum