Package: emacs;
Reported by: Alan Mackenzie <acm <at> muc.de>
Date: Fri, 1 Oct 2021 17:12:02 UTC
Severity: normal
Done: João Távora <joaotavora <at> gmail.com>
Bug is archived. No further changes may be made.
Message #118 received at 50946 <at> debbugs.gnu.org (full text, mbox):
From: João Távora <joaotavora <at> gmail.com> To: Eli Zaretskii <eliz <at> gnu.org> Cc: 50946 <at> debbugs.gnu.org Subject: Re: insert-file-contents can corrupt buffers. [Was: bug#50946: Emacs-28: Inadequate coding in hack-elisp-shorthands] Date: Sun, 03 Oct 2021 19:59:24 +0100
Eli Zaretskii <eliz <at> gnu.org> writes:
>> From: João Távora <joaotavora <at> gmail.com>
>> Cc: 50946 <at> debbugs.gnu.org
>> Date: Sun, 03 Oct 2021 18:05:33 +0100
> Note that previously, the shorthand searching and application was
> effectively turned off until very late into the loadup procedure. But
> now, we enable it as soon as files.el is loaded, which is way
> earlier. Somewhere there is the reason for the problem.
Yes, I agree, this makes sense.
> So I think, instead of the fboundp test, introduce a variable,
> say inhibit-shorthands, set it to t at the beginning of loadup, then
> reset to nil after shorthands.el has been loaded.
At this point, I think that's slightly worse than introducing
hack-read-symbol-shorthands-function... or introducing a hook as I had
before.
Given you dislike hooks, the patch with
hack-read-symbol-shorthands-function is below. Looks good?
João
commit d4416d7f2083bd55984193b94241edb76bb2879c
Author: João Távora <joaotavora <at> gmail.com>
Date: Sun Oct 3 16:05:40 2021 +0100
Simplify hack-read-symbol-shorthands again (bug#50946)
* lisp/loadup.el (load-source-file-function): Don't set twice.
* lisp/shorthands.el (hack-read-symbol-shorthands): Simplify.
(load-with-shorthands-and-code-conversion): Remove.
* lisp/international/mule.el (load-with-code-conversion): Call
hack-read-symbol-shorthands-function. Set up shorthands.
(hack-read-symbol-shorthands-function): New variable
diff --git a/lisp/international/mule.el b/lisp/international/mule.el
index 2a855b5673..d00e39d228 100644
--- a/lisp/international/mule.el
+++ b/lisp/international/mule.el
@@ -294,6 +294,9 @@ define-charset
(apply 'define-charset-internal name (mapcar 'cdr attrs))))
+(defvar hack-read-symbol-shorthands-function nil
+ "Holds function to compute `read-symbol-shorthands'.")
+
(defun load-with-code-conversion (fullname file &optional noerror nomessage)
"Execute a file of Lisp code named FILE whose absolute name is FULLNAME.
The file contents are decoded before evaluation if necessary.
@@ -319,7 +322,8 @@ load-with-code-conversion
(let ((load-true-file-name fullname)
(load-file-name fullname)
(set-auto-coding-for-load t)
- (inhibit-file-name-operation nil))
+ (inhibit-file-name-operation nil)
+ shorthands)
(with-current-buffer buffer
;; So that we don't get completely screwed if the
;; file is encoded in some complicated character set,
@@ -328,6 +332,12 @@ load-with-code-conversion
;; Don't let deactivate-mark remain set.
(let (deactivate-mark)
(insert-file-contents fullname))
+ (setq shorthands
+ ;; We need this indirection because hacking local
+ ;; variables in too early seems to have cause recursive
+ ;; load loops (bug#50946).
+ (and hack-read-symbol-shorthands-function
+ (funcall hack-read-symbol-shorthands-function)))
;; If the loaded file was inserted with no-conversion or
;; raw-text coding system, make the buffer unibyte.
;; Otherwise, eval-buffer might try to interpret random
@@ -338,11 +348,13 @@ load-with-code-conversion
(set-buffer-multibyte nil))
;; Make `kill-buffer' quiet.
(set-buffer-modified-p nil))
- ;; Have the original buffer current while we eval.
- (eval-buffer buffer nil
- ;; This is compatible with what `load' does.
- (if dump-mode file fullname)
- nil t))
+ ;; Have the original buffer current while we eval,
+ ;; but consider shorthands of the eval'ed one.
+ (let ((read-symbol-shorthands shorthands))
+ (eval-buffer buffer nil
+ ;; This is compatible with what `load' does.
+ (if dump-mode file fullname)
+ nil t)))
(let (kill-buffer-hook kill-buffer-query-functions)
(kill-buffer buffer)))
(do-after-load-evaluation fullname)
diff --git a/lisp/loadup.el b/lisp/loadup.el
index 3fb6b81328..3a55d2c805 100644
--- a/lisp/loadup.el
+++ b/lisp/loadup.el
@@ -355,7 +355,6 @@
(load "paren")
(load "shorthands")
-(setq load-source-file-function #'load-with-shorthands-and-code-conversion)
(load "emacs-lisp/eldoc")
(load "cus-start") ;Late to reduce customize-rogue (needs loaddefs.el anyway)
diff --git a/lisp/shorthands.el b/lisp/shorthands.el
index c31ef3d216..40a960ff7d 100644
--- a/lisp/shorthands.el
+++ b/lisp/shorthands.el
@@ -28,35 +28,15 @@
(require 'files)
(eval-when-compile (require 'cl-lib))
-(defun hack-read-symbol-shorthands (fullname)
- "Return value of `read-symbol-shorthands' file-local variable in FULLNAME.
-FULLNAME is the absolute file name of an Elisp .el file which
-potentially specifies a file-local value for
-`read-symbol-shorthands'. The Elisp code in FULLNAME isn't read
-or evaluated in any way, except for extraction of the
-buffer-local value of `read-symbol-shorthands'."
- (let* ((size (nth 7 (file-attributes fullname)))
- (from (max 0 (- size 3000)))
- (to size))
- (with-temp-buffer
- (while (and (< (buffer-size) 3000) (>= from 0))
- (insert-file-contents fullname nil from to)
- (setq to from
- from (cond
- ((= from 0) -1)
- (t (max 0 (- from 100))))))
- ;; FIXME: relies on the `hack-local-variables--find-variables'
- ;; detail of files.el. That function should be exported,
- ;; possibly be refactored into two parts, since we're only
- ;; interested in basic "Local Variables" parsing.
- (alist-get 'read-symbol-shorthands (hack-local-variables--find-variables)))))
-
-(defun load-with-shorthands-and-code-conversion (fullname file noerror nomessage)
- "Like `load-with-code-conversion', but also consider Elisp shorthands.
-This function uses shorthands defined in the file FULLNAME's local
-value of `read-symbol-shorthands', when it processes that file's Elisp code."
- (let ((read-symbol-shorthands (hack-read-symbol-shorthands fullname)))
- (load-with-code-conversion fullname file noerror nomessage)))
+(defun hack-read-symbol-shorthands ()
+ "Compute `read-symbol-shorthands' from Local Variables section."
+ ;; FIXME: relies on the `hack-local-variables--find-variables'
+ ;; detail of files.el. That function should be exported,
+ ;; possibly be refactored into two parts, since we're only
+ ;; interested in basic "Local Variables" parsing.
+ (alist-get 'read-symbol-shorthands (hack-local-variables--find-variables)))
+
+(setq hack-read-symbol-shorthands-function #'hack-read-symbol-shorthands)
;; FIXME: move this all to progmodes/elisp-mode.el? OTOH it'd make
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