Re: [PATCH 1/6] fix ambiguous errno treating after mktime()

[David Laight <david%l8s.co.uk@localhost>]

On Thu, Aug 21, 2008 at 05:26:31PM +0200, Joerg Sonnenberger wrote:
> On Thu, Aug 21, 2008 at 06:02:10PM +0300, Andy Shevchenko wrote:
> > The SUSv3 describes errno value only for C extension, but we can reset
> > errno to drop ambiguous treating its value.
> 
> I object libc resetting errno.

It is my recollection that errno is only well defined after a function
(that sets errno) returns -1 and may be changed even if such a function
succeeds.

There are a few exceptoions (eg strtoul() and some maths function) which
will set errno on failure and leave it unchanged on success - applications
being required to set errno = 0 before a sequence of such calls.

        David

-- 
David Laight: david%l8s.co.uk@localhost