Changeset 51986 in webkit for trunk/JavaScriptCore/wtf/DateMath.cpp

Timestamp:

Dec 11, 2009, 7:39:30 AM (15 years ago)

Author:

[email protected]

Message:

2009-12-11 Kent Tamura <​[email protected]>

Reviewed by Darin Adler.

Fix a problem that JSC::gregorianDateTimeToMS() returns a negative
value for a huge year value.
​https://bugs.webkit.org/show_bug.cgi?id=32304

• wtf/DateMath.cpp: (WTF::dateToDaysFrom1970): Renamed from dateToDayInYear, and changed the return type to double. (WTF::calculateDSTOffset): Follow the dateToDaysFrom1970() change. (WTF::timeClip): Use maxECMAScriptTime. (JSC::gregorianDateTimeToMS): Follow the dateToDaysFrom1970() change.

2009-12-11 Kent Tamura <​[email protected]>

Reviewed by Darin Adler.

Fix a problem that JSC::gregorianDateTimeToMS() returns a negative
value for a huge year value.
​https://bugs.webkit.org/show_bug.cgi?id=32304

• fast/js/date-daysfrom1970-overflow-expected.txt: Added.
• fast/js/date-daysfrom1970-overflow.html: Added.
• fast/js/script-tests/date-daysfrom1970-overflow.js: Added.

File:

• trunk/JavaScriptCore/wtf/DateMath.cpp (modified) (6 diffs)

trunk/JavaScriptCore/wtf/DateMath.cpp

@@ -121 +121 @@
 
 static const double maxUnixTime = 2145859200.0; // 12/31/2037
+// ECMAScript asks not to support for a date of which total
+// millisecond value is larger than the following value.
+// See 15.9.1.14 of ECMA-262 5th edition.
+static const double maxECMAScriptTime = 8.64E15;
 
 // Day of year for the first day of each month, where index 0 is January, and day 0 is January 1.
@@ -307 +311 @@
 }
 
-static int dateToDayInYear(int year, int month, int day)
+static double dateToDaysFrom1970(int year, int month, int day)
 {
     year += month / 12;
@@ -317 +321 @@
     }
 
-    int yearday = static_cast<int>(floor(daysFrom1970ToYear(year)));
+    double yearday = floor(daysFrom1970ToYear(year));
+    ASSERT((year >= 1970 && yearday >= 0) || (year < 1970 && yearday < 0));
     int monthday = monthToDayInYear(month, isLeapYear(year));
 
@@ -453 +458 @@
         int dayInMonth = dayInMonthFromDayInYear(dayInYearLocal, leapYear);
         int month = monthFromDayInYear(dayInYearLocal, leapYear);
-        int day = dateToDayInYear(equivalentYear, month, dayInMonth);
+        double day = dateToDaysFrom1970(equivalentYear, month, dayInMonth);
         ms = (day * msPerDay) + msToMilliseconds(ms);
     }
@@ -842 +847 @@
     if (!isfinite(t))
         return NaN;
-    if (fabs(t) > 8.64E15)
+    if (fabs(t) > maxECMAScriptTime)
         return NaN;
     return trunc(t);
@@ -928 +933 @@
 double gregorianDateTimeToMS(ExecState* exec, const GregorianDateTime& t, double milliSeconds, bool inputIsUTC)
 {
-    int day = dateToDayInYear(t.year + 1900, t.month, t.monthDay);
+    double day = dateToDaysFrom1970(t.year + 1900, t.month, t.monthDay);
     double ms = timeToMS(t.hour, t.minute, t.second, milliSeconds);
     double result = (day * WTF::msPerDay) + ms;