* time.c (search_time_t): limit guess range by mktime if it is

availabe.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@6049 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Tue Mar 30 20:25:34 2004  Tanaka Akira  <akr@m17n.org>
+
+	* time.c (search_time_t): limit guess range by mktime if it is
+	  availabe.
+
 Tue Mar 30 18:19:00 2004  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* eval.c (rb_eval): fix SEGV at retry in iterator's receiver.

test/ruby/test_time.rb

@@ -23,4 +23,14 @@ class TestTime < Test::Unit::TestCase
     assert_equal(Time.utc(2000, 3, 21, 0, 30)  \
                 -Time.utc(2000, 3, 21, 3, 30), -3*3600)
   end
+
+  def test_negative
+    begin
+      Time.at(-1)
+    rescue ArgumentError
+      return
+    end
+    assert_equal(-1, Time.utc(1969, 12, 31, 23, 59, 59).tv_sec)
+    assert_equal(-2, Time.utc(1969, 12, 31, 23, 59, 58).tv_sec)
+  end
 end

time.c

@@ -444,6 +444,15 @@ search_time_t(tptr, utc_p)
                (1UL << (8 * sizeof(time_t) - 1)) - 1 :
 	       ~(time_t)0;
 
+#if defined(HAVE_MKTIME)
+    if ((guess = mktime(tptr)) != -1) {
+      if (guess_lo < guess - 24 * 60 * 60)
+        guess_lo = guess - 24 * 60 * 60;
+      if (guess + 24 * 60 * 60 < guess_hi)
+        guess_hi = guess + 24 * 60 * 60;
+    }
+#endif
+
     tm = (utc_p ? gmtime : localtime)(&guess_lo);
     if (!tm) goto error;
     d = tmcmp(tptr, tm);