- (condition-case err
- (run-hook-with-args 'jit-lock-functions start next)
- ;; If the user quits (which shouldn't happen in normal on-the-fly
- ;; jit-locking), make sure the fontification will be performed
- ;; before displaying the block again.
- (quit (put-text-property start next 'fontified nil)
- (funcall 'signal (car err) (cdr err))))
-
- ;; The redisplay engine has already rendered the buffer up-to
- ;; `orig-start' and won't notice if the above jit-lock-functions
- ;; changed the appearance of any part of the buffer prior
- ;; to that. So if `start' is before `orig-start', we need to
- ;; cause a new redisplay cycle after this one so that any changes
- ;; are properly reflected on screen.
- ;; To make such repeated redisplay happen less often, we can
- ;; eagerly extend the refontified region with
- ;; jit-lock-after-change-extend-region-functions.
- (when (< start orig-start)
- (run-with-timer 0 nil #'jit-lock-force-redisplay
- (copy-marker start) (copy-marker orig-start)))
-
- ;; Find the start of the next chunk, if any.
- (setq start (text-property-any next end 'fontified nil))))))))
+ (pcase-let
+ ;; `tight' is the part we've fully refontified, and `loose'
+ ;; is the part we've partly refontified (some of the
+ ;; functions have refontified it but maybe not all).
+ ((`(,tight-beg ,tight-end ,loose-beg ,_loose-end)
+ (condition-case err
+ (jit-lock--run-functions start next)
+ ;; If the user quits (which shouldn't happen in normal
+ ;; on-the-fly jit-locking), make sure the fontification
+ ;; will be performed before displaying the block again.
+ (quit (put-text-property start next 'fontified nil)
+ (signal (car err) (cdr err))))))
+
+ ;; In case we fontified more than requested, take advantage of the
+ ;; good news.
+ (when (or (< tight-beg start) (> tight-end next))
+ (put-text-property tight-beg tight-end 'fontified t))
+
+ ;; Make sure the contextual refontification doesn't re-refontify
+ ;; what's already been refontified.
+ (when (and jit-lock-context-unfontify-pos
+ (< jit-lock-context-unfontify-pos tight-end)
+ (>= jit-lock-context-unfontify-pos tight-beg)
+ ;; Don't move boundary forward if we have to
+ ;; refontify previous text. Otherwise, we risk moving
+ ;; it past the end of the multiline property and thus
+ ;; forget about this multiline region altogether.
+ (not (get-text-property tight-beg
+ 'jit-lock-defer-multiline)))
+ (setq jit-lock-context-unfontify-pos tight-end))
+
+ ;; The redisplay engine has already rendered the buffer up-to
+ ;; `orig-start' and won't notice if the above jit-lock-functions
+ ;; changed the appearance of any part of the buffer prior
+ ;; to that. So if `loose-beg' is before `orig-start', we need to
+ ;; cause a new redisplay cycle after this one so that the changes
+ ;; are properly reflected on screen.
+ ;; To make such repeated redisplay happen less often, we can
+ ;; eagerly extend the refontified region with
+ ;; jit-lock-after-change-extend-region-functions.
+ (when (< loose-beg orig-start)
+ (run-with-timer 0 nil #'jit-lock-force-redisplay
+ (copy-marker loose-beg)
+ (copy-marker orig-start)))
+
+ ;; Find the start of the next chunk, if any.
+ (setq start
+ (text-property-any tight-end end 'fontified nil)))))))))