[Patch v6 1/6] tag-util: factor out rules for illegal tags, use in parse_tag_line

[David Bremner]

Mark Walters <markwalters1009 at gmail.com> writes:

> I don't know if this matters but it seems that one can still add a "-"
> tag by doing something like
>
> echo "+%2d -- search" | notmuch tag --batch
>
> This might be the right thing to do but I thought I would mention it.

I _think_ it's a feature, so I'm tempted to document it and move on
unless somebody convinces me it's a bad idea.

d