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Re: [PATCH] Fix multiple minor tzset glitches [BZ #24004]
- From: Florian Weimer <fweimer at redhat dot com>
- To: Paul Eggert <eggert at cs dot ucla dot edu>
- Cc: libc-alpha at sourceware dot org
- Date: Wed, 10 Apr 2019 13:57:05 +0200
- Subject: Re: [PATCH] Fix multiple minor tzset glitches [BZ #24004]
- References: <20190211163728.31655-1-eggert@cs.ucla.edu> <87h8d1e8tk.fsf@oldenburg2.str.redhat.com> <9f3882f6-e056-95d1-4506-58fd87cbf6c2@cs.ucla.edu>
* Paul Eggert:
> On 2/18/19 1:37 AM, Florian Weimer wrote:
>> I thought this polling (for reloading /etc/localtime if it has changed)
>> was a feature. I'm not sure if we can remove it.
>
> No such polling is documented. On the contrary, the glibc manual says
> that an unset TZ is treated as if it were set to
> ':/etc/localtime'. There is no polling when you set
> TZ=':/etc/localtime' (or to TZ='/etc/localtime', or to any other
> value). So the code and the documentation disagree, and one or the
> other needs to be fixed.
>
> Neither Solaris nor OpenBSD poll, so portable programs cannot assume
> that polling occurs. (These are the only two other systems I checked.)
It turns out that polling was implemented in response to this user bug
report:
<https://sourceware.org/bugzilla/show_bug.cgi?id=154>
I must say that the use case in the bug report is not unreasonable.
Thanks,
Florian