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.

2 files changed, 12 insertions, 1 deletions

diff --git a/lisp/emacs-lisp/autoload.el b/lisp/emacs-lisp/autoload.el
index 4a9bd6d06b3..e811ee23fea 100644
--- a/lisp/emacs-lisp/autoload.el
+++ b/lisp/emacs-lisp/autoload.el
@@ -873,12 +873,18 @@ FILE's modification time."
 ;; 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 d769a155aa0..48bbd618712 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -1896,10 +1896,15 @@ The value is non-nil if there were no errors, nil if errors."
                        ;; 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