From 45fa5e97248360369c19feaee9479d22be544c8c Mon Sep 17 00:00:00 2001 From: Stefan Monnier Date: Tue, 12 May 2020 16:51:55 -0400 Subject: [PATCH] * lisp/emacs-lisp/syntax.el: Fix bug#41195 Allow use of `syntax-ppss-flush-cache` in `syntax-propertize-function`. (syntax-propertize--inhibit-flush): New var. (syntax-propertize): Bind it. (syntax-ppss-flush-cache): Test it. --- lisp/emacs-lisp/syntax.el | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/lisp/emacs-lisp/syntax.el b/lisp/emacs-lisp/syntax.el index 3294378754a..46dc8d9ade8 100644 --- a/lisp/emacs-lisp/syntax.el +++ b/lisp/emacs-lisp/syntax.el @@ -63,9 +63,10 @@ override the buffer's syntax table for special syntactic constructs that cannot be handled just by the buffer's syntax-table. The specified function may call `syntax-ppss' on any position -before END, but it should not call `syntax-ppss-flush-cache', -which means that it should not call `syntax-ppss' on some -position and later modify the buffer on some earlier position.") +before END, but if it calls `syntax-ppss' on some +position and later modifies the buffer on some earlier position, +then it is its responsability to call `syntax-ppss-flush-cache' to flush +the now obsolete ppss info from the cache.") (defvar syntax-propertize-chunk-size 500) @@ -320,6 +321,11 @@ END) suitable for `syntax-propertize-function'." (defvar-local syntax-ppss-table nil "Syntax-table to use during `syntax-ppss', if any.") +(defvar-local syntax-propertize--inhibit-flush nil + "If non-nil, `syntax-ppss-flush-cache' only flushes the ppss cache. +Otherwise it flushes both the ppss cache and the properties +set by `syntax-propertize'") + (defun syntax-propertize (pos) "Ensure that syntax-table properties are set until POS (a buffer point)." (when (< syntax-propertize--done pos) @@ -375,8 +381,13 @@ END) suitable for `syntax-propertize-function'." ;; (message "syntax-propertizing from %s to %s" start end) (remove-text-properties start end '(syntax-table nil syntax-multiline nil)) - ;; Avoid recursion! - (let ((syntax-propertize--done most-positive-fixnum)) + ;; Make sure we only let-bind it buffer-locally. + (make-local-variable 'syntax-propertize--inhibit-flush) + ;; Let-bind `syntax-propertize--done' to avoid infinite recursion! + (let ((syntax-propertize--done most-positive-fixnum) + ;; Let `syntax-propertize-function' call + ;; `syntax-ppss-flush-cache' without worries. + (syntax-propertize--inhibit-flush t)) (funcall syntax-propertize-function start end))))))))) ;;; Link syntax-propertize with syntax.c. @@ -455,7 +466,8 @@ These are valid when the buffer has no restriction.") (defun syntax-ppss-flush-cache (beg &rest ignored) "Flush the cache of `syntax-ppss' starting at position BEG." ;; Set syntax-propertize to refontify anything past beg. - (setq syntax-propertize--done (min beg syntax-propertize--done)) + (unless syntax-propertize--inhibit-flush + (setq syntax-propertize--done (min beg syntax-propertize--done))) ;; Flush invalid cache entries. (dolist (cell (list syntax-ppss-wide syntax-ppss-narrow)) (pcase cell -- 2.39.2