On 9/3/21 9:53 AM, Edward Tomasz Napierała via tz wrote:
The use case is to make the applications handle moving between timezones, or changing the default system timezone.
Does the use case include installing new timezone tables when a new tzdb release comes out? Or is it to handle only the case where /etc/timezone changes because the system has moved or has changed its default timezone for other reasons? Won't the change break applications like 'zdump' that call 'localtime' several times and assume that all the 'localtime' calls return consistent values for a single timezone? Perhaps it would be better to do change detection only when tzset is called explicitly; this would be less likely to break zdump etc. A smaller question: when opening the TZif file for the first time, wouldn't it be more efficient (and avoid a race) to do open+fstat instead of stat+open?