[tz] disclaimer removals

[Clive D.W. Feather]

Ian Abbott said:
> > Please fix it so that it does not pass char into the isfoo() functions
> > since they have undefined results for negative values other than -1.
> > 
> > http://pubs.opengroup.org/onlinepubs/009695399/functions/isalnum.html
> > 
> > An easy fix is to cast the value to unsigned char.
> 
> I believe you replied to the wrong thread, but isascii() should be
> defined for all integer values:
> 
> http://pubs.opengroup.org/onlinepubs/009695399/functions/isascii.html
> 
> and the code only calls isalnum() if isascii() returns a non-zero value.

isascii isn't part of the C Standard. It is better to follow C, which says
that the argument to all the is* functions should be an unsigned char or
EOF (which is what getc() and friends return).

-- 
Clive D.W. Feather          | If you lie to the compiler,
Email: clive at davros.org     | it will get its revenge.
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