Re: parse-options does not recognize "unspecified" behavior

On Thu, Mar 17, 2016 at 3:07 AM, Eric Sunshine [off-list ref] wrote:

The goal comes from his GSoC microproject. Specifically, Pranit wants
an "unspecified" value. The reason is that he is adding a
commit.verbose=<level> config variable to back the existing git-commit
--verbose option. Any use of --verbose (one or more times) or
--no-verbose should override the config.verbose value altogether, so
he wants a way to know if --verbose or --no-verbose was used; hence
the "unspecified" value. And, really, this issue isn't necessarily
specific to git-commit. It could apply to any command that understands
verbosity levels and wants to be able to get them from both a config
variable and a command-line option.

A much easier solution would be to update OPT_VERBOSE() to understand
that negative values are "unspecified", and then --verbose would
(pseudocode):

    if (value < 0)
        value = 0
    value++;

and --no-verbose would:

    value = 0

That should be compatible with existing clients of OPT__VERBOSE()
which initialize the value to 0, and should satisfy Pranit's case; he
can initialize it to -1, and if it is still -1 when option parsing is
done, then he knows that neither --verbose nor --no-verbose was seen.

This is a much easier solution. I didn't think of this. This type of
problem can only arise with only verbose, so it would be better to
specifically change that part of code.