Re: lib/40422: struct tm cannot represent full range of 64-bit time_t,breaks mktime(3)

[Matthias Drochner <M.Drochner%fz-juelich.de@localhost>]

The following reply was made to PR lib/40422; it has been noted by GNATS.

From: Matthias Drochner <M.Drochner%fz-juelich.de@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: lib-bug-people%NetBSD.org@localhost, gnats-admin%NetBSD.org@localhost,
        netbsd-bugs%NetBSD.org@localhost
Subject: Re: lib/40422: struct tm cannot represent full range of 64-bit 
        time_t,breaks mktime(3)
Date: Mon, 19 Jan 2009 12:41:10 +0100

 Sorry, I was abroad and didn't read list mail, otherwise
 I'd have mentioned your PR in the commit msg.
 (and it would have saved me some time to identify the
 function in localtime.c where the overflow happens)
 
 tnn%NetBSD.org@localhost said:
 > functions like localtime(3) need to be aware of this and should return
 > NULL and set errno appropriately if the time is too large to be
 > represented
 
 Yes, but with the current localtime.c the change looks invasive.
 (As I understand it the overflow happens in timesub() which
 has no return value.)
 Just had a look at tzcode2008h - timesub() can return an error,
 and it seems to do the right check.
 
 So I think the way to go is to update the code to the
 current tzcode release (which is 2008h or the upcoming
 2009a - see Robert Elz's mail to tech-userlevel).
 localtime.c rev. 1.43 should fix the problem for
 applications as long as they use "reasonable" time_t
 values. (Could you test with your testcases?)
 I'd suggest to defer the additional localtime()
 etc checks until tzcode is updated.
 
 best regards
 Matthias
 
 
 
 
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