[tz] localtime.c patch

Clive D.W. Feather clive at davros.org
Tue Oct 7 21:28:23 UTC 2014

Arthur David Olson said:
> Back in the 1980s (when this code had its origins), NULL pointers weren't
> guaranteed to be all zeroes; having a static, otherwise unused structure
> (which was guaranteed to be initialized correctly) for initialization
> purposes was cheap portability insurance. (The insurance was taken out
> consistently, both for uniformity and to avoid problems if a pointer was
> added to a structure later.) Given updates to the C standard and waning
> interest in supporting old systems, this insurance may well no longer be
> needed.

Disagree. The standard still doesn't say that you can memset to 0 to get a
NULL pointer. Embedded systems in particular may well have odd setups that
mean that a NULL pointer isn't a zero bit pattern (I currently develop on a
system where a char is 16 bits and there's something important at address

Clive D.W. Feather          | If you lie to the compiler,
Email: clive at davros.org     | it will get its revenge.
Web: http://www.davros.org  |   - Henry Spencer
Mobile: +44 7973 377646

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