From: siena@... (Siena. / SHINAGAWA, Norihide)
Date: 2004-01-18T03:21:14+09:00
Subject: [ruby-dev:22608] Time#[+-] when given a negative argument

Siena. です。

せっかく CVS アカウントをいただいたのにいろいろあって動けずじまいでした。
改めて、今後とも宜しくお願い致します。

さて、ruby/test/test_time.rb が Time#- でエラーになるので直してみました。
｜RangeError: time - -28800.000000 out of Time range

うちは、time_t が unsigned long なので、
下記のキャストのために sec がとんでもない値になるのが原因でした。

ruby/time.c
｜    time_t sec, usec;
｜    double f, d, v;
(略)
｜    sec = (time_t)f;

不恰好ですが、とりあえず次のテストはこのパッチで通るようになりました。
time_t が負数を受け付ける環境でも大丈夫だとは思うのですが、
どなたか試してみていただけないでしょうか。


# ruby/test/test_time.rb
require 'test/unit'

class TestTime < Test::Unit::TestCase
  def test_time_add()
    assert_equal(Time.utc(2000, 3, 21, 3, 30) + 3 * 3600,
                 Time.utc(2000, 3, 21, 6, 30))
    assert_equal(Time.utc(2000, 3, 21, 3, 30) + (-3 * 3600),
                 Time.utc(2000, 3, 21, 0, 30))
  end

  def test_time_sub()
    assert_equal(Time.utc(2000, 3, 21, 3, 30) - 3 * 3600,
                 Time.utc(2000, 3, 21, 0, 30))
    assert_equal(Time.utc(2000, 3, 21, 3, 30) - (-3 * 3600),
                 Time.utc(2000, 3, 21, 6, 30))
  end

  def test_time_time()
    assert_equal(Time.utc(2000, 3, 21, 3, 30)  \
                -Time.utc(2000, 3, 21, 0, 30), 3 * 3600)
    assert_equal(Time.utc(2000, 3, 21, 0, 30)  \
                -Time.utc(2000, 3, 21, 3, 30), -3 * 3600)
  end
end

Index: ruby/time.c
===================================================================
RCS file: /src/ruby/time.c,v
retrieving revision 1.92
diff -u -p -2 -r1.92 time.c
--- ruby/time.c	30 Dec 2003 16:36:05 -0000	1.92
+++ ruby/time.c	17 Jan 2004 17:51:27 -0000
@@ -1184,4 +1184,5 @@ time_plus(time1, time2)
     time_t sec, usec;
     double f, d, v;
+    int sign;
 
     GetTimeval(time1, tobj);
@@ -1192,4 +1193,6 @@ time_plus(time1, time2)
     v = NUM2DBL(time2);
     d = modf(v, &f);
+    sign = ( f < 0 ? -1 : 1 );
+    f *= sign;
     sec = (time_t)f;
     if (f != (double)sec) {
@@ -1197,14 +1200,14 @@ time_plus(time1, time2)
     }
 #ifndef NEGATIVE_TIME_T
-    if (f < 0 && -f >= tobj->tv.tv_sec) {
+    if (sign < 0 && f >= tobj->tv.tv_sec) {
 	rb_raise(rb_eArgError, "time must be positive");
     }
 #endif
     usec = tobj->tv.tv_usec + (time_t)(d*1e6);
-    sec = tobj->tv.tv_sec + (time_t)f;
+    sec = tobj->tv.tv_sec + sign * sec;
 
 #ifdef NEGATIVE_TIME_T
-    if ((tobj->tv.tv_sec >= 0 && f >= 0 && sec < 0) ||
-	(tobj->tv.tv_sec <= 0 && f <= 0 && sec > 0)) {
+    if ((tobj->tv.tv_sec >= 0 && sign >= 0 && sec < 0) ||
+	(tobj->tv.tv_sec <= 0 && sign <= 0 && sec > 0)) {
 	rb_raise(rb_eRangeError, "time + %f out of Time range", v);
     }
@@ -1240,4 +1243,5 @@ time_minus(time1, time2)
     time_t sec, usec;
     double f, d, v;
+    int sign;
 
     GetTimeval(time1, tobj);
@@ -1254,4 +1258,6 @@ time_minus(time1, time2)
     v = NUM2DBL(time2);
     d = modf(v, &f);
+    sign = ( f < 0 ? -1 : 1 );
+    f *= sign;
     sec = (time_t)f;
     if (f != (double)sec) {
@@ -1259,13 +1265,13 @@ time_minus(time1, time2)
     }
 #ifndef NEGATIVE_TIME_T
-    if (f > 0 && f >= tobj->tv.tv_sec) {
+    if (sign > 0 && f >= tobj->tv.tv_sec) {
 	rb_raise(rb_eArgError, "time must be positive");
     }
 #endif
     usec = tobj->tv.tv_usec - (time_t)(d*1e6);
-    sec = tobj->tv.tv_sec - (time_t)f;
+    sec = tobj->tv.tv_sec - sign * sec;
 #ifdef NEGATIVE_TIME_T
-    if ((tobj->tv.tv_sec <= 0 && f >= 0 && sec > 0) ||
-	(tobj->tv.tv_sec >= 0 && f <= 0 && sec < 0)) {
+    if ((tobj->tv.tv_sec <= 0 && sign >= 0 && sec > 0) ||
+	(tobj->tv.tv_sec >= 0 && sign <= 0 && sec < 0)) {
 	rb_raise(rb_eRangeError, "time - %f out of Time range", v);
     }


---
Siena. <mailto:siena@faculty.chiba-u.jp>