bug#23186: closed (Re: bug#23186: 25.0.92; Tramp: Windows does not always set COMSPEC, tramp blows up in a string-match)

[Jerry Asher]

Your bug closing excuse is defamatory, there were no personal attacks on you. 

There was criticism of your behavior and how you examine and respond to bug reports. None of that constitutes a personal attack on you.

Your closing a bug report that describes a valid bug because you dislike how the conversation you initiated went, is support for my criticism of how you respond to bug reports.

On Sat, Apr 2, 2016 at 10:32 AM, Jerry Asher <ja2038@gmail.com> wrote:

Heh, a bug report is a bug report REGARDLESS of how you felt you were treated.

Since you started off your response to me 

+ disparaging my bug report

+ misrepresenting what I said

+ summarizing it inaccurately

+ dismissing the evidence

You received in kind a report filled with frustration.

I can just see other people closing bug reports that discuss a clearly documented and widely reported bug as seen by google searches with responses like "I felt reporter was mean to me so I closed this bug report."

Jerry

On Sat, Apr 2, 2016 at 10:28 AM, GNU bug Tracking System <help-debbugs@gnu.org> wrote:

Your bug report

#23186: 25.0.92; Tramp: Windows does not always set COMSPEC, tramp blows up in a string-match

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to 23186@debbugs.gnu.org.

--
23186: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=23186
GNU Bug Tracking System
Contact help-debbugs@gnu.org with problems

---------- Forwarded message ----------
From: Eli Zaretskii <eliz@gnu.org>
To: 23186-done@debbugs.gnu.org
Cc: 
Date: Sat, 02 Apr 2016 20:26:41 +0300
Subject: Re: bug#23186: 25.0.92; Tramp: Windows does not always set COMSPEC, tramp blows up in a string-match
> Date: Sat, 02 Apr 2016 19:44:18 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 23186@debbugs.gnu.org
>
> What is the full contents of the environment of the Emacs process when
> you run that zapped binary?

Since the OP refused to answer even the above simplest question, and
instead sent off-list a hostile email with personal attacks on me, I'm
closing this bug report.



---------- Forwarded message ----------
From: Jerry Asher <ja2038@gmail.com>
To: bug-gnu-emacs@gnu.org
Cc: 
Date: Sat, 2 Apr 2016 09:06:57 -0700
Subject: 25.0.92; Tramp: Windows does not always set COMSPEC, tramp blows up in a string-match

--text follows this line--

I started the 64 bit version of windows emacs from a shortcut on my taskbar. I
created the shortcut a few minutes ago by running emacs from the command
line, then pinning the shortcut. (There is a big caveat and I'll discuss
that at the end.)

Starting emacs up in restoring my desktop it loaded a python file. That
python file triggered python mode. Somewhere in there, ...

Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  string-match("cmd\\.exe" nil)
  (if (string-match "cmd\\.exe" tramp-encoding-shell) "/c" "-c")
  eval((if (string-match "cmd\\.exe" tramp-encoding-shell) "/c" "-c"))
  custom-initialize-reset(tramp-encoding-command-switch (if (string-match "cmd\\.exe" tramp-encoding-shell) "/c" "-c"))
  custom-declare-variable(tramp-encoding-command-switch (if (string-match "cmd\\.exe" tramp-encoding-shell) "/c" "-c") "Use this switch together with `tramp-encoding-shell' for local commands.\nSee the variable `tramp-encoding-shell' for more information." :group tramp :type string)
  byte-code("\300\301!\210\302\303\304\305\306\307\306\310\311\312\313\314& \210\315\316\317\320\306\303\321\322& \210\315\323\324\325\306\303\321\326& \210\327\330!\203:

I believe the problem is in tramp.el which assumes that COMSPEC has been set.

(defcustom tramp-encoding-shell
  (if (memq system-type '(windows-nt))
      (getenv "COMSPEC")
    "/bin/sh")

The problem is that Windows can sometimes (see caveat below) start emacs such that COMSPEC is not defined.

I think perhaps a fix would be something along the lines of:

(defcustom tramp-encoding-shell
  (if (memq system-type '(windows-nt))
      (or (getenv "COMSPEC")
          (concat (getenv "systemroot") "\\system32\\cmd.exe"))
    "/bin/sh")

I'm not a windows developer, but it seems that modulo the systemroot, the system32\cmd.exe path is always (?) the right path.

So here's the caveat, I have poked the emacs.exe image so that it does not start as a console app, but so that it starts as a windows app. Now, I am not a windows developer, I do not know that this is why COMSPEC has not been set, but boy, it's got to be, right? ?

For more on how to poke the emacs.exe image to start as a windows app, see here https://github.com/jerryasher/consoleAppToWin basically, doing so seems to make both ntemacs and cygwin emacs run a bit nicer, and so far, this is the only issue I've seen crop up.

Now, you might reasonably claim that since I am starting up emacs in a very non-standard unsupported manner, the issue is totally mine and no fix is necessary. And there is some logic to that.

Regardless, I would say the assumption that COMSPEC is always set and so therefore if it fails it is okay to assign nil to tramp-encoding-shell knowing that later on it will be in a string-match is problematic in and of itself. 

But I've seen other users report the basic cmd.exe tramp-encoding-shell string match problem, see:

https://www.google.com/search?q=string-match%28"cmd%5C%5C.exe"+nil%29+tramp-encoding-shell

I don't know that my fix would fix those issues as well, but those issues point to a basic problem where tramp-encoding-shell is set to nil and then later compared in string-match.

So why not assign tramp-encoding-shell a default that will probably work instead?

Thanks,

Jerry Asher

In GNU Emacs 25.0.92.1 (x86_64-w64-mingw32)
 of 2016-03-03 built on KAEL
Windowing system distributor 'Microsoft Corp.', version 6.1.7601
Configured using:
 'configure --prefix=/tmp/emacs --without-imagemagick 'CFLAGS=-O2
 -fomit-frame-pointer -g0''

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND DBUS NOTIFY ACL GNUTLS LIBXML2 ZLIB
TOOLKIT_SCROLL_BARS

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

Major mode: Emacs-Lisp

Minor modes in effect:
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  shell-dirtrack-mode: t
  display-time-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  menu-bar-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
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
Mark saved where search started
Mark set
nil
Auto-saving...
Unable to load color "peach"
Mark set [3 times]
Quit
Mark saved where search started [2 times]
Auto-saving...done
Unable to load color "peach" [2 times]

Load-path shadows:
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c:/Users/Jerry/Dropbox/elpa/seq-2.15/seq hides c:/gnu/emacs-bin-w64-25.0.92-O2/emacs/share/emacs/25.0.92/lisp/emacs-lisp/seq
c:/gnu/emacs-bin-w64-25.0.92-O2/emacs/share/emacs/25.0.92/lisp/emacs-lisp/cl-generic hides c:/Users/Jerry/Dropbox/elpa/cl-generic-0.2/cl-generic

Features:
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eldoc-init dired-init dev-requires desktop-init cygwin-init cygwin-mount
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cl-loaddefs pcase cl-lib amazon-tweaks update-auto-loads utf-coding
required-libraries print-list key-bindings finder-inf slime-autoloads
info package easymenu epg-config time cus-start cus-load time-date
mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks
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Memory information:
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 (symbols 56 30368 0)
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 (strings 32 54134 10687)
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