Re: [PATCH 1/8] pkt-line: remove buffer arg from write_packetized_from_fd_no_flush()

"Jeff Hostetler via GitGitGadget" [off-list ref] writes:

From: Jeff Hostetler <redacted>

Remove the scratch buffer argument from `write_packetized_from_fd_no_flush()`
and allocate a temporary buffer within the function.

In 3e4447f1ea (pkt-line: eliminate the need for static buffer in
packet_write_gently(), 2021-02-13) we added the argument in order to
get rid of a static buffer to make the routine safe in multi-threaded
contexts and to avoid putting a very large buffer on the stack.  This
delegated the problem to the caller who has more knowledge of the use
case and can best decide the most efficient way to provide such a
buffer.

However, in practice, the (currently, only) caller just created the
buffer on the stack, so we might as well just allocate it within the
function and restore the original API.

Hmph, I would have expected, since we already have changed the
callchain to pass the buffer down, that we'd keep the structure and
update the caller to heap-allocate, but I think I like the result of
this patch better.  It's not like the caller can allocate and reuse
a single buffer with repeated calls to the function; rather, the
caller makes a single call that results in relaying many bytes by
the helper, all done in a loop, and it is sufficient for the helper
to allocate/deallocate outside of its loop to reuse the buffer.