calendar-[beginning/end]-of-year bugged

[Chong Yidong]

calendar-beginning-of-year and calendar-end-of-year are buggy. For example:

1. M-x calendar  (Suppose it is February 27 2005)
2. M->           (Moves cursor to December 31 2005)
3. M-<           (Moves cursor back to February 27 2005)
Expected behavior: move cursor to January 1 2005.

1. M-x calendar  (Suppose it is February 27 2005)
2. C-u 2 M->     (Moves cursor to December 2004)
Expected behavior: move cursor to December 2006

I have re-written the relevant functions to be correct. Here is the patch:

*** emacs/lisp/calendar/cal-move.el~    Mon Sep  1 23:45:19 2003
--- emacs/lisp/calendar/cal-move.el     Sun Feb 27 13:52:35 2005
***************
*** 257,294 ****
  (defun calendar-beginning-of-year (arg)
    "Move the cursor backward ARG year beginnings."
    (interactive "p")
!   (calendar-cursor-to-nearest-date)
!   (let* ((date (calendar-cursor-to-date))
!          (month (extract-calendar-month date))
!          (day (extract-calendar-day date))
!          (year (extract-calendar-year date))
!          (jan-first (list 1 1 year))
           (calendar-move-hook nil))
!     (if (and (= day 1) (= 1 month))
!         (calendar-backward-month (* 12 arg))
!       (if (and (= arg 1)
!                (calendar-date-is-visible-p jan-first))
!           (calendar-cursor-to-visible-date jan-first)
!         (calendar-other-month 1 (- year (1- arg))))))
    (run-hooks 'calendar-move-hook))

  (defun calendar-end-of-year (arg)
    "Move the cursor forward ARG year beginnings."
    (interactive "p")
!   (calendar-cursor-to-nearest-date)
!   (let* ((date (calendar-cursor-to-date))
!          (month (extract-calendar-month date))
!          (day (extract-calendar-day date))
!          (year (extract-calendar-year date))
!          (dec-31 (list 12 31 year))
           (calendar-move-hook nil))
!     (if (and (= day 31) (= 12 month))
!         (calendar-forward-month (* 12 arg))
!       (if (and (= arg 1)
!                (calendar-date-is-visible-p dec-31))
!           (calendar-cursor-to-visible-date dec-31)
!         (calendar-other-month 12 (- year (1- arg)))
!         (calendar-cursor-to-visible-date (list 12 31 displayed-year)))))
    (run-hooks 'calendar-move-hook))

  (defun calendar-cursor-to-visible-date (date)
--- 257,287 ----
  (defun calendar-beginning-of-year (arg)
    "Move the cursor backward ARG year beginnings."
    (interactive "p")
!   (let* ((cursor-date (calendar-cursor-to-nearest-date))
!          (target-year (- (extract-calendar-year cursor-date) (1- arg)))
!          (target-date (list 1 1 target-year))
           (calendar-move-hook nil))
!     (if (and (= (extract-calendar-day   cursor-date) 1)
!              (= (extract-calendar-month cursor-date) 1))
!         (calendar-backward-year arg)
!       (if (not (calendar-date-is-visible-p target-date))
!           (calendar-other-month 1 target-year))
!       (calendar-cursor-to-visible-date target-date)))
    (run-hooks 'calendar-move-hook))

  (defun calendar-end-of-year (arg)
    "Move the cursor forward ARG year beginnings."
    (interactive "p")
!   (let* ((cursor-date (calendar-cursor-to-nearest-date))
!          (target-year (+ (extract-calendar-year cursor-date) (1- arg)))
!          (target-date (list 12 31 target-year))
           (calendar-move-hook nil))
!     (if (and (= (extract-calendar-day   cursor-date) 31)
!              (= (extract-calendar-month cursor-date) 12))
!         (calendar-forward-year arg)
!       (if (not (calendar-date-is-visible-p target-date))
!           (calendar-other-month 12 target-year))
!       (calendar-cursor-to-visible-date target-date)))
    (run-hooks 'calendar-move-hook))

  (defun calendar-cursor-to-visible-date (date)