151912 - Cookie isn't deleted when setting "expired=1 Jan 1970 00:00:00 GMT"

Status: RESOLVED FIXED

(Core :: Networking: Cookies, defect)

Description

[Michal Nazarewicz]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.1a) Gecko/20020611
BuildID:    2002061104

To delete cookie we use:

document.ccokie="name=value; expires=date"

where date is date in the past. When I use thic code in Mozilla, cookie is still
awailable...

Reproducible: Always
Steps to Reproduce:
Try this code:

<script language="javascript" type="text/javascript"><!--
document.write('<b>document.cookie</b> = <b>"',document.cookie,'"</b><br>\n');
document.write('Setting cookie... (TestCookie=TestValue)');
document.cookie="TestCookie=TestValue";
document.write(' Done.<br />\n');
document.write('<b>document.cookie</b> = <b>"',document.cookie,'"</b><br>\n');
var date=new Date(); date.setYear(date.getYear()-1);
document.write('Deleteing cookie... (TestCookie=DEL;
expires='+date.toGMTString()+')');
document.cookie="TestCookie=DEL; expires="+date.toGMTString();
document.write(' Done.<br />\n');
document.write('<b>document.cookie</b> = <b>"',document.cookie,'"</b><br>\n');
//--></script>


Actual Results:  we see: 

document.cookie = ""
Setting cookie... (TestCookie=TestValue) Done.
document.cookie = "TestCookie=TestValue"
Deleteing cookie... (TestCookie=DEL; expires=Tue, 14 Jun 0101 22:54:44 GMT) Done.
document.cookie = "TestCookie=DEL"

Expected Results:  You should repair that problem :)

I have found only one solution. Set value "ThisCookieIsDeleted" and in script,
test if value of cookie, that you have founded, isn't equal to "ThisCookieIsDeleted"

PS. Sorry for my bad english :)

Comment 1

[Phil Schwartau]

I have to mark this bug Invalid.

The problem is that you are using the .getYear() method, which does not
return a four-digit year in Mozilla. See bug 22964, bug 45764, and bug 100123.
Use the .getFullYear() method instead, and things should work fine.

I will attach a testcase below showing both .getYear() and .getFullYear().
In IE, they are the same, but Mozilla they are not.

Comment 2

[Phil Schwartau]

Attachment: Testcase showing effect of .getYear() and .getFullYear()

Comment 3

[Phil Schwartau]

Marking Verified Invalid. 

Try the testcase above in different browsers. You'll see that
in 2002, (new Date()).getYear() returns "102" in Netscape4.7
and in Mozilla/Netscape 7.

But if you use .getFullYear(), you will get "2002" as desired.
Note also, .setFullYear() is preferred over .setYear()

Comment 4

[Michal Nazarewicz]

Well, I haven't fought about this :)
But any way: Why this:

var date=new Date(); date.setTime(0);
document.cookie="TestCookie=DEL; expires="+date.toGMTString();

or this:

theDoc.cookie="TestCookie=DEL; expires=Thu, 1 Jan 1970 00:00:00 GMT";

code dosen't work. However this code:

theDoc.cookie="TestCookie=DEL; expires=Thu, 1 Jan 1970 00:00:01 GMT";

works...

Comment 5

[Phil Schwartau]

OK, this is now a Cookies question; reassigning to Cookies component -

Comment 6

[Stephen P. Morse]

Without testing this out, I'm going to take a stab as to what I think is 
happening.  By setting the date to 1 Jan 1970 00:00:00, you are giving it a time 
of 0 since this is the very beginning of the epoch.  And a time of 0 is 
interpreted (rightly so) as a session cookie.

Does the cookie manager indicate that this cookie expires at the end of the 
session?  And, equivalently, does the cookie vanish the next time you launch the 
browser?  If so, then this is the correct behavior.

Comment 7

[Michal Nazarewicz]

It looks like you have right. After Mozilla's restart cookie disappears :).
Any way: IMHO it's a BUG! IMHO time of 0 shouldn't be interprated as end of session. When I want to set a session cookie I put no "expires=...".

PS. In 2nd and 3rd example from my previous comment "theDoc" means "document" :p

Comment 8

[Suresh]

hmm... ok, looks like using the date to indicate session cookies is problematic.  

marking CONFIRMED.  reducing severity.

Comment 9

[[e-mail]]

Attachment: Expiry testcase

Checkin to bug 156725 fixed this problem.

Verified fixed, per attached testcase.

Comment 10

[[e-mail]]

Attachment: Working testcase

Sorry, previous testcase got mangled by bugzilla.

Comment 11

[[e-mail]]

Marking RESOLVED/FIXED

Comment 12

[Jo Hermans]

*** Bug 208046 has been marked as a duplicate of this bug. ***

Comment 13

[benc]

VERIFIED: Mozilla 1.4b, Mach-O.

I also found that this test case could use some checking code for the javascript
cookie permissions.

If anyone has any code handy that can check for that, please email me.
Otherwise, I'll hack it together as I test the other platforms and hack my
javascript skills up to snuff.