9939 - new Date (year, month, negative day) sets day to 1

Status: VERIFIED FIXED

(Core :: JavaScript Engine, defect, P3)

Description

[martin.honnen]

Calling
  new Date(1999, 6, -6)
shows
  Thu Jul 01 00:00:00 GMT+0200 (W. Europe Daylight Time) 1999
while in NN3 and IE it shows
  Thu Jun 24 00:00:00 W. Europe Daylight Time 1999
On a short glance at ecma I think the nn3 and IE behaviour is correct.

Comment 1

[martin.honnen]

Attachment: bug demo

Comment 2

[Mike McCabe]

Martin -

Looks like you're correct.  Hopefully this is rare enough that it hasn't tripped
anyone up...

Are there any other similar bugs where negative arguments should be interpreted,
but are not?

Thanks -
Mike

Comment 3

[Mike McCabe]

Martin - thanks for finding the problem!

This diff fixes it.

There was a specific check for date < 1, which leads me to believe that this is
the only case where we ignored a negative argument.


cvs diff jsdate.c
Index: jsdate.c
===================================================================
RCS file: /cvsroot/mozilla/js/src/jsdate.c,v
retrieving revision 3.18
diff -r3.18 jsdate.c
1798c1798,1802
<               array[loop] = 0;
---
>                 if (loop == 2) { /* Default date argument to 1. */
>                     array[loop] = 1;
>                 } else {
>                     array[loop] = 0;
>                 }
1809,1813d1812
<
<       /* if we got a 0 for 'date' (which is out of range)
<        * pretend it's a 1 */
<       if (array[2] < 1)
<           array[2] = 1;


Awaiting an open tree to check it in on.

Comment 4

[Mike McCabe]

Checked in a fix.

Comment 5

[John Unruh]

verified fixed.