Error in datestr.m in Octave-3.2.0 MingW

[Philip Nienhuis]

John W. Eaton wrote:
> On 23-Jun-2009, Michael Goffioul wrote:
> 
> | On Tue, Jun 23, 2009 at 9:30 PM, Michael
> | Goffioul<michael.goffioul at gmail.com> wrote:
> | > On Tue, Jun 23, 2009 at 9:22 PM, John W. Eaton<jwe at octave.org> wrote:
> | >> OK.  Does the generated config.h file for Octave define HAVE_STRFTIME?
> | >> You can also look at the output of
> | >>
> | >>  octave_config_info ("DEFS")
> | >>
> | >> If HAVE_STRFTIME is not defined on these systems, then the bug is
> | >> likely in the strftime.c that is part of Octave.  Maybe we need to
> | >> find a newer version.
> | >
> | > (current archive build, with MSVC)
> | >
> | > octave:4> strfind(octave_config_info ("DEFS"), 'STRFTIME')
> | > ans = [](1x0)
> | 
> | However,
> | 
> | octave:8> datestr(datenum(1970, 1, 1))
> | ans = 01-Jan-1970
> | octave:9> datestr(datenum(1970, 1, 2))
> | ans = 02-Jan-1970
> 
> I would expect anything on or after 1-1-1970 to work. <snip>

You mean: AFTER 1 Jan 1970 (>719529). Currently, the datestr.m of Octave 
3.2.0 MingW fails for all dates BEFORE 2 Jan 1970 (see my original bug 
report).

Are you really sure that strftime() is buggy? Comparing the datestr.m 
files of octave versions 3.0.3 and 3.2.0 I see lots of changes.

Digging a bit further, and echoeing strftime's arguments, i.e. variable:
- df
and expression:
- localtime(mktime(tm))
in the erroneous datestr.m, I see:

*******************************<Screen copy:>********************
GNU Octave, version 3.2.0
Copyright (C) 2009 John W. Eaton and others.
This is free software; see the source code for copying conditions.
There is ABSOLUTELY NO WARRANTY; not even for MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  For details, type `warranty'.

Octave was configured for "i686-pc-mingw32".

Additional information about Octave is available at http://www.octave.org.

Please contribute if you find this software useful.
For more information, visit http://www.octave.org/help-wanted.html

Report bugs to <bug at octave.org> (but first, please read
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warning: mark_as_command is obsolete and will be removed from a future 
version of Octave
octave-3.2.0.exe:1 > date_str(datenum(1970,1,1))
df = %d-%b-%Y
ans =
{
   usec = 0
   sec = 0
   min = 0
   hour = 0
   mday = 0
   mon = 0
   year = 0
   wday = 0
   yday = 0
   isdst = 0
   zone = unknown
}

ans = 00-Jan-1900
octave-3.2.0.exe:2 > date_str(datenum(1970,1,2))
df = %d-%b-%Y
ans =
{
   usec = 0
   sec = 0
   min = 0
   hour = 0
   mday =  2
   mon = 0
   year =  70
   wday =  5
   yday =  1
   isdst = 0
   zone = W. Europe Standard Time
}

ans = 02-Jan-1970
octave-3.2.0.exe:3 >
*******************************</Screen copy>********************

The same happens in the VC++ octave-3.0.3 Windows version.

I conclude that the arguments for the call to strftime() are in error.
Intriguing is that it only seems to happen on Windows.

Philip