bug#1589: 23.0.60; vc-dir erroneously reports "No changes between working revision and workfile"

[Eric Hanchrow]

Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the emacs-pretest-bug@gnu.org mailing list.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

Edit the third line of this script to point to your Emacs, and then run it.

  #!/bin/sh -x

  EMACS=/usr/local/src/emacs-with-my-tweaks.git/src/emacs

  cd /tmp
  rm -rf xyzzy

  mkdir xyzzy
  cd xyzzy
  git init
  mkdir Jack Jill
  touch Jack/it Jill/it
  git add .
  git commit -m "golly!"
  echo More stuff >> Jack/it
  cd Jill

  git status
  # You should see this output:
  
  # On branch master
  # Changed but not updated:
  #   (use "git add <file>..." to update what will be committed)
  #   (use "git checkout -- <file>..." to discard changes in working directory)
  #
  #       modified:   ../Jack/it
  #

  $EMACS -Q \
      --eval '(cd "/tmp/xyzzy/Jill")' \
      --eval '(vc-dir "/tmp/xyzzy/Jill")'

  # note that we're now looking at something like

  #   VC backend : Git
  #   Working dir: /tmp/xyzzy/Jill/
  #   Branch     : master
  #   
  #                             ./
  #                             Jack/
  #        edited               Jack/it
  #   
  #   

  # That seems a bit odd, since the name "Jack/it" doesn't name anything
  # at all when interpreted relative to /tmp/xyzzy/Jill.

  # Furthermore, if you move point to "Jack/it" (by typing "n" twice),
  # and then invoke vc-diff by typing "=", Emacs will respond with "No
  # changes between working revision and workfile", which is wrong; the
  # file is indeed modified.

If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
    `bt full' and `xbacktrace'.
If you would like to further debug the crash, please read the file
/usr/local/src/emacs/etc/DEBUG for instructions.


In GNU Emacs 23.0.60.3 (i686-pc-linux-gnu, GTK+ Version 2.14.4)
 of 2008-12-14 on debian
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: nil
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Shell

Minor modes in effect:
  erc-ring-mode: t
  erc-pcomplete-mode: t
  erc-netsplit-mode: t
  erc-button-mode: t
  erc-fill-mode: t
  erc-stamp-mode: t
  erc-autojoin-mode: t
  erc-track-mode: t
  erc-track-minor-mode: t
  erc-match-mode: t
  erc-services-mode: t
  erc-networks-mode: t
  erc-irccontrols-mode: t
  erc-noncommands-mode: t
  erc-readonly-mode: t
  desktop-save-mode: t
  display-time-mode: t
  global-auto-revert-mode: t
  diff-auto-refine-mode: t
  shell-dirtrack-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
E T RET o o t TAB C-c C-u C-c C-@ C-c C-@ C-c C-@ 0 
_ o RET C-u C-p C-u C-p C-u C-p ESC b RET ESC > t h 
a t SPC p i x DEL c SPC i s SPC a i r b r u s h e d 
SPC b e y o n d SPC r e c o g n i t i o n RET C-c C-@ 
/ m e SPC a h o y s , SPC b e l ESC / RET C-r < e l 
i > ESC > e l i TAB : SPC b e l a t e d SPC p o n g 
RET C-c C-@ C-c C-@ C-c C-@ C-c C-@ C-c C-@ t o o f 
l e DEL DEL DEL d l e - o o RET C-c C-@ C-x d C-g C-x 
b s c h RET y e p RET w a i t . RET i s n ' t SPC " 
I R L " SPC I r e l a n d ? RET C-x b s h e RET c d 
RET c d SPC d o o TAB m z TAB DEL DEL s c TAB ESC DEL 
s c TAB ESC DEL a n TAB s c TAB m z TAB RET g i t SPC 
s t a t u s RET C-x d RET g C-n RET ESC O ESC C-o ESC 
C-o o # DEL DEL # SPC O h SPC w o w ! ! C-x C-s C-x 
k RET C-x v d RET n n = q ESC x r e p o r t - e m c 
a s TAB DEL DEL DEL a TAB RET

Recent messages:
Completed
No completions of doodles/mz
Completing file name...
No completions of doodles/mz
Completed [4 times]
Partially completed
~/doodles/anagrams/scheme/mzscheme 
Wrote /home/erich/doodles/anagrams/scheme/mzscheme/GNUmakefile
Finding changes in 
/home/erich/doodles/anagrams/scheme/mzscheme/scheme/mzscheme/GNUmakefile...
No changes between working revision and workfile

-- 
If there were a little guy running around inside the computer
executing our programs, he would probably have as long and
plaintive a tale to tell about his job as a federal government
employee.
        -- Paul Graham