[PATCH] argp: argp.doc prints incorrectly when it starts with "\v" [BZ #19038]

[Florian Weimer]

* Girish Joshi:

> In argp-help.c `char *vt` is being initialized only once. It needs to
> be initialized for every child in the doc and it needs to be printed
> only in two cases.

> 1. There are no children and the doc does not starts with '\v'.
> 2. Argument `first_only` to the function `argp_doc` is false and the
> complete doc needs to be printed.

I assume this bug user-visible, so it should have a bug in Bugzilla
<https://sourceware.org/bugzilla/>.  Would you please file one?

Could you write a test case for this?  Or at least post how to reproduce
the issue in a minimal program?

Thanks,
Florian