Re: [PATCH v2 1/5] t3430: drop unnecessary one-shot "VAR=val shell-func" invocation

> Eric Sunshine <ericsunshine@charter.net> writes:
> > The behavior of a one-shot environment variable assignment of the form
> > "VAR=val cmd" is undefined according to POSIX when "cmd" is a shell
>
> Please use the right word to describe what the standard says.
>
> Throughout the topic's discussion, you seem to be repeating
> "undefined", but the word POSIX uses for this particular unportable
> behaviour is "unspecified".  The differences are subtle, and for
> programs that want to be conformant, there is no practical
> difference (in other words, we should not rely on the existence or
> validity of the value or behaviour if we wanted to be portable).
>
> The former is what results from use of an invalid construct or
> feeding an invalid data input.  The implementation can do whatever
> it wants to do once you trigger an undefined behaviour.  The latter
> is what results from use of a valid construct or valid data input,
> but outcome may differ across implementations.  An "unspecified"
> behaviour often are still consistent and sensible within a single
> conformant implementation.