bug#23600: 25.1.50; encode-time returns wrong result

[Paul Eggert <eggert@cs.ucla.edu>]

Eli Zaretskii wrote:

> Do callers of putenv expect the argument to be destroyed?

Yes and no. POSIX says that the environment can be modified in-place, so a 
caller of putenv (S) should be prepared for *S to be modified (which is what I 
assume you mean by "destroyed") because the string will be put into the 
environment. Also, POSIX allows putenv to modify *S, as S is of type char * and 
there is no prohibition in the standard against putenv modifying the pointed-to 
storage. That being said, I don't know of any POSIXish implementation of putenv 
(S) that modifies *S and I doubt whether any mainstream implementation would do 
that.

Although the code you mention is stretching things a bit, it's not stretching 
them beyond recognition: the intent of putenv ("TZ=<JST>-9") is not really "set 
the 'TZ' value to the byte-string '<JST>-9' in the environment array", it's more 
"set the time zone to 9 hours ahead of UTC and with abbreviation 'JST'", and on 
MS-Windows the code implements this intent more faithfully than doing nothing would.