bug#40248: 27.0.90; Failure open .authinfo.gpg from Gnus

[Juan José García Ripoll]

Symptoms:
0. Install Gnu Privacy Guard for Windows or similar (non-msys) alternatives
1. Save login information in .authinfo.gpg
2. Launch Emacs on Windows
3. Launch Gnus (assumes an imap account is configured with a server in 
.authinfo.gpg)
4. Gnus cannot connect to the IMAP server.

What is happening:
1. Gnus calls nnimap-open-connection-1
2. nnimap-open-connection-1 binds (coding-system-for-read 'binary)
3. nnimap-credentials is invoked, which starts a chaing of calls ending
up in epg-config--make-gpg-configuration
4. This function uses call-process
5. Because the coding system is set to 'binary, the DOS ^M characters
are exposed and stored in the temporary buffer.
6. When epg-config--make-gpg-configuration parses the output from
gpg.exe, it stores those characters in the configuration and version
fields.
7. The system cannot parse those strings and concludes that there is no
suitable gpg.exe file in the system.

Workaround:
Invoke (epg-find-configuration 'OpenPGP) from .emacs. In this situation,
Emacs' call-process uses a suitable encoding to parse the output.

Fix:
a. Set a suitable value for the encoding around call-process in
epg-config--make-gpg-configuration. Unfortunately, I do not know which
value would work in non-Windows platforms.

b. Rewrite all regexps in epg-config--make-gpg-configuration to ignore
^M characters. Unfortunately I am unfamiliar with gpg.exe's output
format to do this with confidence.

c. Revert to previous behavior in epg-config.el

--- c:/Users/juanj/scoop/apps/emacs/27/share/emacs/27.0.90/lisp/epg-config.el   
2020-03-26 23:37:05.096603400 +0100
+++ 
c:/Users/juanj/scoop/apps/emacs/27/share/emacs/27.0.90/lisp/epg-config-new.el   
    2020-03-27 00:06:26.138870700 +0100
@@ -181,7 +181,7 @@
 
 ;; Create an `epg-configuration' object for `gpg', using PROGRAM.
 (defun epg-config--make-gpg-configuration (program)
-  (let (config groups type args)
+  (let (config groups type args (coding-system-for-read nil))
     (with-temp-buffer
       (apply #'call-process program nil (list t nil) nil
             (append (if epg-gpg-home-directory



In GNU Emacs 27.0.90 (build 5, x86_64-w64-mingw32)
 of 2020-03-25 built on DESKTOP-3A8AAJ0
Repository revision: 4860530f3c130c6f854ea83dcc03f59e535a33ba
Repository branch: emacs-27
Windowing system distributor 'Microsoft Corp.', version 10.0.18363
System Description: Microsoft Windows 10 Pro for Workstations 
(v10.0.1909.18363.720)

Recent messages:
Sending email  
Sending email done
Sending...done
command-execute: Command attempted to use minibuffer while in minibuffer
e is undefined
p is undefined
Quit
Making completion list...

ESC M-x is undefined
Quit
Configured using:
 'configure --without-dbus --host=x86_64-w64-mingw32
 --without-compress-install 'CFLAGS=-O2 -static -g3''

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY W32NOTIFY ACL GNUTLS LIBXML2
HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS MODULES THREADS JSON PDUMPER LCMS2 GMP

Important settings:
  value of $LANG: ESN
  locale-coding-system: cp1252

Major mode: Emacs-Lisp

Minor modes in effect:
  ido-vertical-mode: t
  save-place-mode: t
  savehist-mode: t
  gcmh-mode: t
  override-global-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(gnutls epa-file network-stream nsm smtpmail qp pp shadow sort vc-git
diff-mode mailalias bbdb-mua bbdb-com crm bbdb bbdb-site timezone
org-mime ox-org org-protocol ox-reveal cl ox-odt rng-loc rng-uri
rng-parse rng-match rng-dt rng-util rng-pttrn nxml-parse nxml-ns
nxml-enc xmltok nxml-util ox-latex ox-icalendar ox-html table ox-ascii
ox-publish ox org-element avl-tree generator org org-macro org-footnote
org-pcomplete pcomplete org-list org-faces org-entities org-version
ob-python ob ob-tangle org-src ob-ref ob-lob ob-table ob-exp ob-comint
comint ansi-color ring ob-emacs-lisp ob-core ob-eval org-table ol
org-keys org-compat org-macs org-loaddefs noutline outline face-remap
mail-extr warnings emacsbug message rmc puny format-spec rfc822 mml
mml-sec epa derived epg epg-config mailabbrev gmm-utils mailheader
eieio-opt speedbar sb-image ezimage dframe cal-menu calendar
cal-loaddefs thingatpt help-fns radix-tree benchmark-init-modes
mm-decode mm-bodies mm-encode mail-parse rfc2231 debug backtrace
find-func mailcap pcase ido-vertical-mode ido gnus-win gnus nnheader
gnus-util rmail rmail-loaddefs text-property-search time-date sendmail
rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils dired
dired-loaddefs grayscale-theme saveplace savehist edmacro kmacro
cus-edit cus-start cus-load wid-edit benchmark-init advice gcmh diminish
cl-extra help-mode use-package use-package-ensure use-package-delight
use-package-diminish use-package-bind-key bind-key easy-mmode
use-package-core finder-inf tex-site info package easymenu browse-url
url-handlers url-parse auth-source cl-seq eieio eieio-core cl-macs
eieio-loaddefs password-cache json subr-x map url-vars seq byte-opt gv
bytecomp byte-compile cconv cl-loaddefs cl-lib tooltip eldoc electric
uniquify ediff-hook vc-hooks lisp-float-type mwheel dos-w32 ls-lisp
disp-table term/w32-win w32-win w32-vars term/common-win tool-bar dnd
fontset image regexp-opt fringe tabulated-list replace newcomment
text-mode elisp-mode lisp-mode prog-mode register page tab-bar menu-bar
rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core term/tty-colors frame 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 simple 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 w32notify w32
lcms2 multi-tty make-network-process emacs)

Memory information:
((conses 16 411297 173966)
 (symbols 48 26521 16)
 (strings 32 148179 19593)
 (string-bytes 1 4021443)
 (vectors 16 50121)
 (vector-slots 8 1383982 345852)
 (floats 8 278 875)
 (intervals 56 1333 586)
 (buffers 1000 21))

-- 
Juan José García Ripoll

Quantum Information and Foundations Group
Institute of Fundamental Physics IFF-CSIC
Calle Serrano 113b, Madrid 28006 Spain
http://quinfog.hbar.es - http://juanjose.garcia.ripoll