bug#10980: 23.4; Variable init_environment incorrectly set

[Bo Johansson]

Hej!

 

--------------------------- Background

I am used to "live" in Emacs and want to get the same result doing something from within Emacs as doing it from a Windows command prompt.

For example (compile "dmake" nil) in Emacs and executing dmake in a Windows command window should give the same result.

 

--------------------------- Example of Problems

Emacs replaces the environment variable SHELL at start up in Windows to something like "C:/Program Files (x86)/GNU Emacs 23.4/bin/cmdproxy.exe". Processes started by Emacs will inherit this value.

 

Many utilities uses SHELL. One example is:  With " ... cmdproxy.exe" as value of SHELL dmake is configured to use a Kornshell compatible shell.

 

--------------------------- Solution ideas

A long time goal should be to avoid changing the environment variable within Emacs. Emacs should (internally) at least not change the value of SHELL.

 

A short time solution is to make the initial environment variable available as stated in http://www.gnu.org/software/emacs/manual/html_node/emacs/Environment.html: "The variable initial-environment stores the initial environment inherited by Emacs".

 

This make it possible in

emacs-git/lisp/progmodes/compile.el:1479

(defun compilation-start (command &optional mode name-function highlight-regexp)

to use the variable compilation-environment to temporary override the in emacs internal used environment variables.

 

In emacs-git/lisp/progmodes/simple.el:2088

(defun shell-command (command &optional output-buffer error-buffer)

the corresponding possibility is however not available.

 

--------------------------- Description of the Bug

Below follows a list of steps done at start up. The problem is that step 2) changes the environment variables before step 4) sets the variable initial_environment.

 

1) The function init_environment is called

 

emacs-git/src/emacs.c:1416

#ifdef MSDOS

  /* Call early 'cause init_environment needs it.  */

  init_dosfns ();

  /* Set defaults for several environment variables.  */

  if (initialized)

    init_environment (argc, argv, skip_args);

  else

    tzset ();

#endif /* MSDOS */

 

#ifdef WINDOWSNT

  globals_of_w32 ();

  /* Initialize environment from registry settings.  */

  init_environment (argv);

  init_ntproc ();    /* must precede init_editfns.  */

#endif

 

2) The function init_environment changes the environment variables

 

T:/emacs-git/src/w32.c:1528:init_environment (char ** argv)

Do a lot of changes to the environment variables.

 

3) The function set_initial_environment is called to save the "initial_environment"

 

emacs-git/src/emacs.c:1440

  /* Initialize and GC-protect Vinitial_environment and

     Vprocess_environment before set_initial_environment fills them

     in.  */

  if (!initialized)

    syms_of_callproc ();

  /* egetenv is a pretty low-level facility, which may get called in

     many circumstances; it seems flimsy to put off initializing it

     until calling init_callproc.  Do not do it when dumping.  */

  if (initialized || ((strcmp (argv[argc-1], "dump") != 0

               && strcmp (argv[argc-1], "bootstrap") != 0)))

    set_initial_environment ();

 

4) The variable initial_environment is set by set_initial_environment

 

emacs-git/src/callproc.c:1616

set_initial_environment (void)

emacs-git/src/callproc.c:1624

Vinitial_environment = Fcopy_sequence (Vprocess_environment);

 

 

-----------------------------------------------------

In GNU Emacs 23.4.1 (i386-mingw-nt6.1.7601)

of 2012-02-04 on MARVIN

Windowing system distributor `Microsoft Corp.', version 6.1.7601

configured using `configure --with-gcc (4.4) --cflags -ID:/devel/emacs/libs/libXpm-3.5.8/include -ID:/devel/emacs/libs/libXpm-3.5.8/src -ID:/devel/emacs/libs/libpng-dev_1.4.3-1/include -ID:/devel/emacs/libs/zlib-dev_1.2.5-2/include -ID:/devel/emacs/libs/giflib-4.1.4-1/include -ID:/devel/emacs/libs/jpeg-6b-4/include -ID:/devel/emacs/libs/tiff-3.8.2-1/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

  value of $XMODIFIERS: nil

  locale-coding-system: cp1252

  default enable-multibyte-characters: t

 

Major mode: Lisp Interaction

 

Minor modes in effect:

  diff-auto-refine-mode: t

  shell-dirtrack-mode: t

  delete-selection-mode: t

  show-paren-mode: t

  cua-mode: t

  tooltip-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-encryption-mode: t

  auto-compression-mode: t

  line-number-mode: t

  transient-mark-mode: t

  auto-fill-mode: t

 

Recent input:

<escape> x r e p o <tab> r <tab> <return>

 

Recent messages:

Loading cua-base...done

Loading paren...done

userDotEmacs Done

Finding all versions of R on your system...

Sorry, no version of R could be found on your system.

Making completion list...

 

Load-path shadows:

None found.

 

Features:

(shadow sort mail-extr message ecomplete rfc822 mml mml-sec

password-cache mm-decode mm-bodies mm-encode mailcap mail-parse rfc2231

rfc2047 rfc2045 qp ietf-drums mailabbrev nnheader gnus-util netrc

time-date mm-util mail-prsvr gmm-utils mailheader canlock sha1 hex-util

hashcash mail-utils emacsbug help-mode view psvn byte-opt warnings

bytecomp byte-compile derived edmacro kmacro wid-edit log-edit pcvs-util

add-log diff-mode easy-mmode pp elp ediff-merg ediff-diff ediff-wind

ediff-mult ediff-help ediff-init ediff-util dired tex-mik preview-latex

tex-site auto-loads ess-eldoc ess-toolbar ess-mouse mouseme thingatpt

browse-url ess-menu ess-swv ess-noweb noweb-font-lock-mode ess-bugs-l

essd-els ess-sas-d ess-sas-l ess-sas-a executable shell ess-arc-d

ess-vst-d ess-xls-d ess-lsp-l ess-sta-d ess-sta-l cc-vars cc-defs

make-regexp ess-sp6w-d ess-sp4-d ess-sp3-d ess-r-d ess-r-args assoc

ess-s-l ess-inf ess-utils comint ring ess-mode noweb-mode ess ess-custom

regexp-opt ess-compat ess-site htmlize-view easymenu w32-winprint

htmlize cl cl-19 delsel server advice help-fns advice-preload paren

cua-base cus-start cus-load tooltip ediff-hook vc-hooks lisp-float-type

mwheel dos-w32 disp-table ls-lisp w32-win w32-vars tool-bar dnd fontset

image fringe lisp-mode register page menu-bar rfn-eshadow timer select

scroll-bar mldrag 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 loaddefs button minibuffer faces cus-face files

text-properties overlay md5 base64 format env code-pages mule custom

widget hashtable-print-readable backquote make-network-process multi-tty

emacs)