branch: elpa/logview
commit 0a1b3a8268a45a0c5a682bc04546dec056fb1950
Author: Paul Pogonyshev <pogonys...@gmail.com>
Commit: Paul Pogonyshev <pogonys...@gmail.com>
Prevent certain errors on Emacs 29 (up to a full freeze) by preventively
disabling its long-line optimization; fail fast if that doesn't help.
---
logview.el | 62 ++++++++++++++++++++++++++++++++++++++++++++++----------------
1 file changed, 46 insertions(+), 16 deletions(-)
diff --git a/logview.el b/logview.el
index a38feab48a..a0819423cb 100644
--- a/logview.el
+++ b/logview.el
@@ -644,6 +644,7 @@ this face is used."
(defvar-local logview--custom-submode-guessed-with 0)
+;; Don't access these as variables directly, use functions with the same name
instead.
(defvar-local logview--point-min nil)
(defvar-local logview--point-max nil)
@@ -859,13 +860,33 @@ works for \\[logview-set-navigation-view] and
\\[logview-highlight-view-entries]
(with-silent-modifications
,@body))))
-(defmacro logview--std-temporarily-widening (&rest body)
+(defmacro logview--temporarily-widening (&rest body)
+ "Execute BODY with the current buffer fully widened.
+Original point restrictions, if any, will not be possible to find
+inside BODY. In most cases (also if not sure) you should use
+macro `logview--std-temporarily-widening' instead."
(declare (indent 0) (debug t))
`(save-restriction
- (let ((logview--point-min (logview--point-min))
- (logview--point-max (logview--point-max)))
- (widen)
- ,@body)))
+ (widen)
+ ,@(when (>= emacs-major-version 29)
+ ;; It is better to fail hard now than to face an arbitrary failure
later. In
+ ;; particular, an infinite loop in fontification code can
irreversibly freeze
+ ;; Emacs, but this is of course "not a bug":
+ ;; https://debbugs.gnu.org/cgi/bugreport.cgi?bug=57804
+ `((unless (and (= (point-min) 1) (= (point-max) (1+ (buffer-size))))
+ (error "Logview is incompatible with locked narrowing; see
https://github.com/doublep/logview#locked-narrowing";))))
+ ,@body))
+
+(defmacro logview--std-temporarily-widening (&rest body)
+ "Execute BODY with the current buffer fully widened.
+Original point restrictions are available as return values of
+functions `logview--point-min' and `logview--point-max'. This
+macro can be nested, with inner calls not changing results of the
+two functions (available since the first call) further."
+ (declare (indent 0) (debug t))
+ `(let ((logview--point-min (logview--point-min))
+ (logview--point-max (logview--point-max)))
+ (logview--temporarily-widening ,@body)))
(defmacro logview--locate-current-entry (entry start &rest body)
(declare (indent 2) (debug (symbolp symbolp body)))
@@ -1114,9 +1135,16 @@ interfere with editing) or if submode wasn't guessed
successfully.")
+;; Emacs 29 (snapshots); need to set it to nil.
+(defvar long-line-threshold)
+
;;;###autoload
(define-derived-mode logview-mode nil "Logview"
"Major mode for viewing and filtering various log files."
+ ;; Logview is incompatible with locked narrowing of Emacs 29. Set this
variable in hope
+ ;; this prevents it from ever happening. See
`logview--temporarily-widening'.
+ (when (boundp 'long-line-threshold)
+ (setq-local long-line-threshold nil))
(logview--update-keymap)
(add-hook 'read-only-mode-hook #'logview--update-keymap nil t)
(setq font-lock-defaults (copy-sequence logview-font-lock-defaults))
@@ -2707,8 +2735,7 @@ returns non-nil."
(if (and (>= temporary-size reassurance-chars)
(string= (buffer-substring-no-properties 1 (1+
reassurance-chars))
(with-current-buffer buffer
- (save-restriction
- (widen)
+ (logview--std-temporarily-widening
(buffer-substring-no-properties compare-from
size)))))
(if (= temporary-size reassurance-chars)
(message "Backing file %s hasn't grown" file)
@@ -2718,8 +2745,7 @@ returns non-nil."
;; This is to avoid unnecessary confirmation about
;; modifying a buffer with externally changed file.
(buffer-file-name nil))
- (save-restriction
- (widen)
+ (logview--std-temporarily-widening
(save-excursion
(goto-char (point-max))
(insert-buffer-substring-no-properties temporary (1+
reassurance-chars) (1+ temporary-size))))
@@ -2732,16 +2758,17 @@ returns non-nil."
;;; Internal functions (except helpers for specific command groups).
-(defvar inhibit-message)
-
(defmacro logview--internal-log (format-string &rest arguments)
`(let ((inhibit-message t))
(message ,format-string ,@arguments)))
(defun logview--guess-submode ()
(save-excursion
- (save-restriction
- (widen)
+ ;; Need access to the buffer start, regardless of any narrowing. Also,
don't want
+ ;; original narrowing to have any effect on anything (see uses of
corresponding
+ ;; functions that access it; not even sure they are even called from here,
but that
+ ;; doesn't matter), that's why not `std'.
+ (logview--temporarily-widening
(let ((line-number 0)
(remaining-attemps (if (and (integerp logview-max-promising-lines)
(> logview-max-promising-lines 0))
logview-max-promising-lines
@@ -3672,7 +3699,10 @@ This list is preserved across Emacs session in
(defun logview--fontify-region (region-start region-end loudly)
(when (logview-initialized-p)
- (logview--std-temporarily-widening
+ ;; We are basically managing narrowing indirectly, by not fontifying
further than
+ ;; `region-end' (possibly expanded). Not using `std' here to prevent
+ ;; `logview--iterate-entries-forward' from stopping early because of outer
narrowing.
+ (logview--temporarily-widening
;; We are very fast. Don't fontify too little to avoid overhead.
;; FIXME: See `font-lock-extend-region-functions'. Might want to reuse
that instead.
(when (and (< region-end (point-max)) (not (get-text-property (1+
region-end) 'fontified)))
@@ -3916,9 +3946,9 @@ This list is preserved across Emacs session in
(defun logview-filter-edit--font-lock-region (region-begin region-end
&optional _old-length)
(save-excursion
(save-match-data
- (save-restriction
+ ;; Not even in a Logview mode buffer, not using `std'.
+ (logview--temporarily-widening
(with-silent-modifications
- (widen)
(goto-char region-begin)
(forward-line 0)
;; Never try to parse from the middle of a multiline filter.
