Rollup merge of #74088 - tmiasko:write-all-vectored-empty, r=KodrAus

Avoid writes without any data in `Write::write_all_vectored`

Previously, when non-empty sequence of empty IoSlices have been provided
to `Write::write_all_vectored`, the buffers would be written as is with
`Write::write_vectored` and subsequently the return value `Ok(0)` would
be misinterpreted as an error.

Avoid writes without any data by advancing the buffers first. This
matches the documented behaviour of `Write::write_all_vectored`
and is analogous to what happens in `Write::write_all`.

0 files changed, 0 insertions, 0 deletions