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* lisp/emacs-lisp/timer.el (timer-event-handler): Don't run if canceled.

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Fixes: debbugs:17392
This commit is contained in:
Stefan Monnier 2014-05-18 08:58:30 -04:00
parent 2f82660963
commit 08a2434e2f
4 changed files with 52 additions and 40 deletions
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80
lisp/emacs-lisp/timer.el
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@ -290,42 +290,50 @@ This function is called, by name, directly by the C code."
(cell
;; Delete from queue. Record the cons cell that was used.
(cancel-timer-internal timer)))
;; Re-schedule if requested.
(if (timer--repeat-delay timer)
(if (timer--idle-delay timer)
(timer-activate-when-idle timer nil cell)
(timer-inc-time timer (timer--repeat-delay timer) 0)
;; If real time has jumped forward,
;; perhaps because Emacs was suspended for a long time,
;; limit how many times things get repeated.
(if (and (numberp timer-max-repeats)
(< 0 (timer-until timer (current-time))))
(let ((repeats (/ (timer-until timer (current-time))
(timer--repeat-delay timer))))
(if (> repeats timer-max-repeats)
(timer-inc-time timer (* (timer--repeat-delay timer)
repeats)))))
;; Place it back on the timer-list before running
;; timer--function, so it can cancel-timer itself.
(timer-activate timer t cell)
(setq retrigger t)))
;; Run handler.
(condition-case-unless-debug err
;; Timer functions should not change the current buffer.
;; If they do, all kinds of nasty surprises can happen,
;; and it can be hellish to track down their source.
(save-current-buffer
(apply (timer--function timer) (timer--args timer)))
(error (message "Error running timer%s: %S"
(if (symbolp (timer--function timer))
(format " `%s'" (timer--function timer)) "")
err)))
(when (and retrigger
;; If the timer's been canceled, don't "retrigger" it
;; since it might still be in the copy of timer-list kept
;; by keyboard.c:timer_check (bug#14156).
(memq timer timer-list))
(setf (timer--triggered timer) nil)))))
;; If `cell' is nil, it means the timer was already canceled, so we
;; shouldn't be running it at all. This can happen for example with the
;; following scenario (bug#17392):
;; - we run timers, starting with A (and remembering the rest as (B C)).
;; - A runs and a does a sit-for.
;; - during sit-for we run timer D which cancels timer B.
;; - timer A finally finishes, so we move on to timers B and C.
(unless cell
;; Re-schedule if requested.
(if (timer--repeat-delay timer)
(if (timer--idle-delay timer)
(timer-activate-when-idle timer nil cell)
(timer-inc-time timer (timer--repeat-delay timer) 0)
;; If real time has jumped forward,
;; perhaps because Emacs was suspended for a long time,
;; limit how many times things get repeated.
(if (and (numberp timer-max-repeats)
(< 0 (timer-until timer (current-time))))
(let ((repeats (/ (timer-until timer (current-time))
(timer--repeat-delay timer))))
(if (> repeats timer-max-repeats)
(timer-inc-time timer (* (timer--repeat-delay timer)
repeats)))))
;; Place it back on the timer-list before running
;; timer--function, so it can cancel-timer itself.
(timer-activate timer t cell)
(setq retrigger t)))
;; Run handler.
(condition-case-unless-debug err
;; Timer functions should not change the current buffer.
;; If they do, all kinds of nasty surprises can happen,
;; and it can be hellish to track down their source.
(save-current-buffer
(apply (timer--function timer) (timer--args timer)))
(error (message "Error running timer%s: %S"
(if (symbolp (timer--function timer))
(format " `%s'" (timer--function timer)) "")
err)))
(when (and retrigger
;; If the timer's been canceled, don't "retrigger" it
;; since it might still be in the copy of timer-list kept
;; by keyboard.c:timer_check (bug#14156).
(memq timer timer-list))
(setf (timer--triggered timer) nil))))))
;; This function is incompatible with the one in levents.el.
(defun timeout-event-p (event)