Re: [Sccs-devel] Bugs handling UTC in 5.08

[Bruce L. <bru...@gm...>]

Partial response:

On Tue, Oct 13, 2015 at 8:44 AM, Joerg Schilling
<Joe...@fo...> wrote:
> Bruce Lilly <bru...@gm...> wrote:
>
>> This started as a bug-fix for prs.c, which wouldn't compile with
>> -DGMT_TIME.  During testing, I found several related bugs, and added some
>> related features which I've been using locally for some time.  These may
>> help with v6.
>
> No, SCCSv6 does not need the workaround introduced by Sun between 1990 and 2006.
> This is because SCCS now supports much better and unique time stamp handling
> that includes GMT-offset.
>
>> Related bugs fixed:
>>
>>  * Incorrect time (not corrected for zone offset) resulting in warnings
>>    about retrieval time being older than delta time (noticeable West of the
>>    Prime Meridian).
>
> Could you please give a test case for the problem you have in mind?

With prs.c patched but w/o the patch to dodelt.c:

Script started on Tue Oct 13 11:48:58 2015
# date -u +%%Z%%%Y-%m-%dT%H:%M:%SZ > test.txt
# /opt/schily/ccs/bin/admin -itest.txt s.test.txt
# rm test.txt
# /opt/schily/ccs/bin/get s.test.txt
Time stamp later than current clock time (co10)
1.1
1 lines
# head -99 test.txt s.test.txt
==> test.txt <==
@(#)2015-10-13T15:49:03Z

==> s.test.txt <==
h09367
s 00001/00000/00000
d D 1.1 15/10/13 15:49:09 root 1 0
c date and time created 15/10/13 15:49:09 by root
e
u
U
f e 0
G r
t
T
I 1
%Z%2015-10-13T15:49:03Z
E 1
#

Script done on Tue Oct 13 11:49:55 2015

Note the erroneous co10 error message.

>> Related features added:
>>
>>  * %N% and %O% keywords added and documented.
>>
>>    These are for current date-time and last applied delta date-time,
>>    respectively.  Format is standard date-time format as documented in:
>
> What is the main purpose for this modification?

The purpose is to provide expansion of date-time in standard format.

> Note that upper case keywords as extensions are not a good idea as they are
> always enabled by default and thus cause compatibility problems with older SCCS
> versions.
>
> ...
>>    Examples:
>>        %N% 2015-10-11T17:55:49.104271752Z
>>        %O% 2015-10-11T11:45:16Z
>>
>>  * Improved parsing of date and time.
>>
>>    In case XPG decides to allow or require standard format date-time in the
>>    s-file.
>
> The format of the s.files is bejond POSIX.

But the p-file isn't, and the existing format suffer from all of the
problems that you noted (and more):

[...]
> possible but still make the known problems disappear. The problems have been:
>
> -       2-digit years is a real problem, fixed by using 4+ digits in V6
>
> -       local time without GMT-offset causes undeterminable time stamps.
>         The problem is even present when always operating in the same timezone
>         as there are DST switches that may the time to appear going backwards.
>         Fixed by always adding a GMT offset.
>
> -       coarse time resolution, fixed by optional second fraction up to
>         nanosecond resolution.