Remove no-longer-needed integer overflow code

* lisp/calculator.el (calculator-number-to-string):
Use truncate, not calculator-truncate, since integer
overflow cannot occur here.
* lisp/calendar/cal-persia.el (calendar-persian-year-from-absolute):
* lisp/gnus/gnus-agent.el (gnus-agent-read-article-number):
* lisp/gnus/nnmaildir.el (nnmaildir--group-maxnum)
(nnmaildir--new-number):
* lisp/scroll-bar.el (scroll-bar-scale):
* lisp/simple.el (beginning-of-buffer, end-of-buffer):
Simplify, now that integer overflow cannot occur.

1 files changed, 1 insertions, 7 deletions

diff --git a/lisp/calendar/cal-persia.el b/lisp/calendar/cal-persia.el
index 897208fd2b4..59fe52a592a 100644
--- a/lisp/calendar/cal-persia.el
+++ b/lisp/calendar/cal-persia.el
@@ -100,13 +100,7 @@ Gregorian date Sunday, December 31, 1 BC."
          (d2                         ; prior days not in n2820 or n768
           (mod d1 280506))
          (n1        ; years not in n2820 or n768
-          ;; Want:
-          ;; (floor (+ (* 2820 d2) (* 2820 366)) 1029983))
-          ;; but that causes overflow, so use the following.
-          ;; Use 366 as the divisor because (2820*366 mod 1029983) is small.
-          (let ((a (floor d2 366))
-                (b (mod d2 366)))
-            (+ 1 a (floor (+ (* 2137 a) (* 2820 b) 2137) 1029983))))
+          (floor (* 2820 (+ d2 366)) 1029983))
          (year (+ (* 2820 n2820)        ; complete 2820 year cycles
                   (* 768 n768)          ; complete 768 year cycles
                   ;; Remaining years.