bug#28244: 26.0.50; byte-compiled files have mode 0600

bug#28244: 26.0.50; byte-compiled files have mode 0600

[Sven Joachim]

I have observed that byte-compiled files have permissions 0600,
regardless of the umask (mine is 022).  This is bad, especially for
system-wide installations.

Looking at the lisp/ directory, this has started between August 2 and
August 8 this year.

,----
|   -rw------- 1 sven src  82133 Aug  8 17:15 replace.elc
|   -rw------- 1 sven src  23081 Aug  8 17:15 ls-lisp.elc
|   -rw-r--r-- 1 sven src  70177 Aug  2 11:36 whitespace.elc
|   -rw-r--r-- 1 sven src   3546 Aug  2 11:36 password-cache.elc
`----

Commit 785a4a1d52fd ("Fix a couple of make-temp-file races") is likely
the culprit, but I haven't verified that.


In GNU Emacs 26.0.50 (build 2, i686-pc-linux-gnu, GTK+ Version 2.24.31)
 of 2017-08-26 built on turtle
Repository revision: cc7530cae09b0aa4d648d92ca0f82c81439a6b34
Windowing system distributor 'The X.Org Foundation', version 11.0.11903000
System Description:	Debian GNU/Linux

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Compiling /tmp/strokes.el...done
Wrote /tmp/strokes.elc

Configured using:
 'configure --build i686-linux-gnu --host i686-linux-gnu --prefix=/usr
 --sharedstatedir=/var/lib --libexecdir=/usr/lib --localstatedir=/var
 --infodir=/usr/share/info/emacs-snapshot --mandir=/usr/share/man
 --without-pop
 --enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/26.0.50/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/26.0.50/site-lisp:/usr/share/emacs/site-lisp
 --without-wide-int --disable-silent-rules --without-compress-install
 --with-x=yes --with-x-toolkit=gtk2 --without-gconf --without-gsettings
 build_alias=i686-linux-gnu host_alias=i686-linux-gnu 'CFLAGS=-g -O2
 -fdebug-prefix-map=/usr/local/src/emacs=. -fstack-protector-strong
 -Wformat -Werror=format-security' 'LDFLAGS=-Wl,-z,relro
 -Wl,--as-needed' 'CPPFLAGS=-Wdate-time -D_FORTIFY_SOURCE=2 -DDEBIAN
 -DSITELOAD_PURESIZE_EXTRA=5000''

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS NOTIFY ACL
LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK2 X11 LIBSYSTEMD

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

Major mode: Lisp Interaction

Minor modes in effect:
  shell-dirtrack-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-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-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:
(shadow sort mail-extr emacsbug message subr-x puny seq dired
dired-loaddefs rfc822 mml easymenu mml-sec epa derived epg epg-config
gnus-util rmail rmail-loaddefs mm-decode mm-bodies mm-encode mail-parse
rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils easy-mmode compile tramp
tramp-compat tramp-loaddefs trampver ucs-normalize shell pcomplete
comint ansi-color ring parse-time format-spec advice auth-source cl-seq
eieio byte-opt eieio-core cl-macs gv eieio-loaddefs password-cache
bytecomp byte-compile cl-loaddefs cl-lib cconv elec-pair time-date
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 facemenu font-core term/tty-colors frame 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 minibuffer
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 dbusbind inotify
dynamic-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty make-network-process emacs)

Memory information:
((conses 8 222247 10475)
 (symbols 24 22368 2)
 (miscs 20 47 151)
 (strings 16 35213 2713)
 (string-bytes 1 1000149)
 (vectors 8 38737)
 (vector-slots 4 768883 14334)
 (floats 8 55 61)
 (intervals 28 263 2)
 (buffers 528 12))

bug#28244: 26.0.50; byte-compiled files have mode 0600

[Paul Eggert]

[-- Attachment #1: Type: text/plain, Size: 147 bytes --]

Thanks for reporting that bug. It was indeed an unintended consequence of my 
earlier change. I installed the attached patch, which should fix it.

[-- Attachment #2: 0001-Fix-over-protection-of-byte-compiled-files.patch --]
[-- Type: text/x-patch, Size: 2672 bytes --]

From 7207e4a3d533d959eebbb947235f741b1586722b Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sat, 26 Aug 2017 23:07:01 -0700
Subject: [PATCH] Fix over-protection of byte-compiled files

Problem reported by Sven Joachim (Bug#28244).
Also, fix similar problem for autoload files.
* lisp/emacs-lisp/autoload.el (autoload--save-buffer):
Set temp file modes to the buffer-file-name file modes (or 666
if not available) as adjusted by umask.
* lisp/emacs-lisp/bytecomp.el (byte-compile-file):
Set temp file modes to 666 as adjusted by umask.
---
 lisp/emacs-lisp/autoload.el | 8 +++++++-
 lisp/emacs-lisp/bytecomp.el | 5 +++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/lisp/emacs-lisp/autoload.el b/lisp/emacs-lisp/autoload.el
index 4a9bd6d..e811ee2 100644
--- a/lisp/emacs-lisp/autoload.el
+++ b/lisp/emacs-lisp/autoload.el
@@ -873,12 +873,18 @@ autoload-generate-file-autoloads
 ;; For parallel builds, to stop another process reading a half-written file.
 (defun autoload--save-buffer ()
   "Save current buffer to its file, atomically."
-  ;; Copied from byte-compile-file.
+  ;; Similar to byte-compile-file.
   (let* ((version-control 'never)
          (tempfile (make-temp-file buffer-file-name))
+	 (default-modes (default-file-modes))
+	 (temp-modes (logand default-modes #o600))
+	 (desired-modes (logand default-modes
+				(or (file-modes buffer-file-name) #o666)))
          (kill-emacs-hook
           (cons (lambda () (ignore-errors (delete-file tempfile)))
                 kill-emacs-hook)))
+    (unless (= temp-modes desired-modes)
+      (set-file-modes tempfile desired-modes))
     (write-region (point-min) (point-max) tempfile nil 1)
     (backup-buffer)
     (rename-file tempfile buffer-file-name t))
diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index d769a15..48bbd61 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -1896,10 +1896,15 @@ byte-compile-file
 		       ;; parallel bootstrap), it does not risk getting a
 		       ;; half-finished file.  (Bug#4196)
 		       (tempfile (make-temp-file target-file))
+		       (default-modes (default-file-modes))
+		       (temp-modes (logand default-modes #o600))
+		       (desired-modes (logand default-modes #o666))
 		       (kill-emacs-hook
 			(cons (lambda () (ignore-errors
 					   (delete-file tempfile)))
 			      kill-emacs-hook)))
+		  (unless (= temp-modes desired-modes)
+		    (set-file-modes tempfile desired-modes))
 		  (write-region (point-min) (point-max) tempfile nil 1)
 		  ;; This has the intentional side effect that any
 		  ;; hard-links to target-file continue to
-- 
2.7.4