[PATCH v3] libio: Flush stream at freopen (BZ#21037)

[Florian Weimer]

* Adhemerval Zanella:

> diff --git a/libio/tst-memstream4.c b/libio/tst-memstream4.c
> new file mode 100644
> index 0000000000..bb2635e837
> --- /dev/null
> +++ b/libio/tst-memstream4.c

> +    //TEST_VERIFY (STRCMP (buf, W("new")) == 0);

This looks like a leftover.

> +    TEST_COMPARE_BLOB (buf, STRLEN (buf), W("new"), STRLEN (W ("new")));

I think you need STRLNE (buf) * sizeof (CHAR_T) here.