Re: Defect in XSHd7 strftime()

["H. Peter Anvin" <yyy@xxxxxxxxx>]

yyyyyy@xxxxxxxxxxxxxxx wrote:

> 1. The specification is unclear on what happens to existing
> local-time-related data, when the environment variable 'TZ' is
> changed.  
>
> In particular, the indended result is unclear in the following
> situation:
> * mktime(), localtime(), or localtime_r() create or modify a
>   'struct tm' value.
> * The 'TZ' environment variable is altered.
> * strftime() is called with the %Z or %z conversion specifiers,
>   with the old 'struct tm' as an argument.
>  
> Some Unix platforms store time zone information in private fields
> within a 'struct tm', and thus output the old time zone.  Some use
> a global variable, and thus output the new time zone.  Some platforms
> store a pointer to a current time zone object, and thus may output
> invalid data.

I believe mktime() cannot be made to operate correctly unless such 
information exists in private fields.

I believe we really should standardize these fields, thus making them 
availavle to all applications.  Unfortunately, that's hardly in scope 
for a defect report.

	-hpa