bug#34180: 27.0.50; argv[0] used incorrectly to find the .pdmp

[Stefan Monnier]

Package: Emacs
Version: 27.0.50


Currently, the first .pdmp file that we try to load is found by adding
".pdmp" to argv[0].
This has 2 problems:

1- It fails miserably if argv[0] is a name relative to $PATH since it
   performs the lookup relative to $PWD instead, which is additionally
   a security issue.

2- If the executable named by argv[0] is a symlink, it does not try to
   follow the symlink in case the .pdmp is stored next to the
   destination rather than next to the source.
   

-- Stefan



In GNU Emacs 27.0.50 (build 1, x86_64-unknown-linux-gnu, GTK+ Version 3.24.3)
 of 2019-01-22 built on alfajor
Repository revision: 4e56ca18c9760d9a9429d71e36bedfe4da879a9c
Repository branch: work
Windowing system distributor 'The X.Org Foundation', version 11.0.12003000
System Description: Debian GNU/Linux buster/sid

Recent messages:
Mark set
Auto-saving...done
Saving file /home/monnier/src/emacs/trunk/src/emacs.c...
Wrote /home/monnier/src/emacs/trunk/src/emacs.c
Saving file /home/monnier/src/emacs/trunk/ChangeLog...
Wrote /home/monnier/src/emacs/trunk/ChangeLog
Mark set
Press C-c C-c when you are done editing.
Enter a change comment.  Type C-c C-c when done
Checking in /home/monnier/src/emacs/trunk/src/emacs.c...done

Configured using:
 'configure -C --enable-checking --with-modules --enable-check-lisp-object-type
 'CFLAGS=-Wall -g3 -Og -Wno-pointer-sign'
 PKG_CONFIG_PATH=/home/monnier/lib/pkgconfig'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS GLIB
NOTIFY INOTIFY GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS CANNOT_DUMP LCMS2
GMP

Important settings:
  value of $LANG: fr_CH.UTF-8
  locale-coding-system: utf-8-unix

Major mode: InactiveMinibuffer

Minor modes in effect:
  c-electric-flag: t
  shell-dirtrack-mode: t
  diff-auto-refine-mode: t
  electric-pair-mode: t
  global-reveal-mode: t
  reveal-mode: t
  auto-insert-mode: t
  savehist-mode: t
  minibuffer-electric-default-mode: t
  global-compact-docstrings-mode: t
  url-handler-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  global-prettify-symbols-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  line-number-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
/home/monnier/src/emacs/elpa/packages/svg/svg hides 
/home/monnier/src/emacs/work/lisp/svg
/home/monnier/src/emacs/elpa/packages/ada-mode/ada-mode hides 
/home/monnier/src/emacs/work/lisp/progmodes/ada-mode
/home/monnier/src/emacs/elpa/packages/ada-mode/ada-stmt hides 
/home/monnier/src/emacs/work/lisp/progmodes/ada-stmt
/home/monnier/src/emacs/elpa/packages/ada-mode/ada-prj hides 
/home/monnier/src/emacs/work/lisp/progmodes/ada-prj
/home/monnier/src/emacs/elpa/packages/ada-mode/ada-xref hides 
/home/monnier/src/emacs/work/lisp/progmodes/ada-xref
/home/monnier/src/emacs/elpa/packages/nadvice/nadvice hides 
/home/monnier/src/emacs/work/lisp/emacs-lisp/nadvice
/home/monnier/src/emacs/elpa/packages/hyperbole/set hides 
/home/monnier/src/emacs/work/lisp/emacs-lisp/set
/home/monnier/src/emacs/elpa/packages/landmark/landmark hides 
/home/monnier/src/emacs/work/lisp/obsolete/landmark
/home/monnier/src/emacs/elpa/packages/crisp/crisp hides 
/home/monnier/src/emacs/work/lisp/obsolete/crisp

Features:
(sort mail-extr emacsbug log-edit message sendmail rmc puny dired
dired-loaddefs format-spec rfc822 mml mml-sec epa derived epg gnus-util
rmail rmail-loaddefs time-date mm-decode mm-bodies mm-encode mail-parse
rfc2231 rfc2047 rfc2045 mm-util ietf-drums mail-prsvr mailabbrev
mail-utils mailheader pcvs-util bug-reference add-log smerge-mode
whitespace vc vc-dispatcher make-mode pulse cc-mode cc-fonts cc-guess
cc-menus cc-cmds cc-styles cc-align cc-engine cc-langs cc-vars cc-defs
etags multifile generator xref project shell pcomplete grep cl-print
cl-extra help-fns radix-tree sm-c-mode smie misearch multi-isearch
lisp-mnt xscheme byte-opt unsafep trace testcover shadow scheme
re-builder profiler inf-lisp ielm gmm-utils ert pp ewoc debug elp edebug
backtrace find-func cl-indent advice cus-edit cus-start cus-load
wid-edit executable copyright view cal-china lunar solar cal-dst
cal-bahai cal-islam cal-hebrew holidays hol-loaddefs cal-french vc-git
diff-mode filecache diary-lib diary-loaddefs cal-move cal-menu calendar
cal-loaddefs server flymake-proc flymake compile comint ansi-color ring
warnings noutline outline easy-mmode flyspell ispell checkdoc thingatpt
help-mode load-dir elec-pair reveal autoinsert savehist minibuf-eldef
disp-table compact-docstrings cl-seq inline kotl-autoloads proof-site
proof-autoloads realgud-recursive-autoloads finder-inf url-auth info
package easymenu epg-config url-handlers url-parse auth-source eieio
eieio-core cl-macs gv eieio-loaddefs password-cache json map url-vars
seq bytecomp byte-compile cconv cl-loaddefs cl-lib mule-util tooltip
eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel
term/x-win x-win term/common-win x-dnd tool-bar dnd fontset image
regexp-opt fringe tabulated-list replace newcomment text-mode elisp-mode
lisp-mode prog-mode register page menu-bar rfn-eshadow isearch timer
select scroll-bar mouse jit-lock font-lock syntax font-core
term/tty-colors frame simple minibuffer cl-generic cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese composite charscript charprop
case-table epa-hook jka-cmpr-hook help abbrev obarray cl-preloaded
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 threads dbusbind inotify lcms2
dynamic-setting system-font-setting font-render-setting move-toolbar gtk
x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 8 239985 30547)
 (symbols 24 18919 0) (strings 16 72751 4613) (string-bytes 1 2323909)
 (vectors 8 43743)
 (vector-slots 4 1324674 45672) (floats 8 584 263) (intervals 28 6233 0)
 (buffers 528 39))