Re: Closing fds twice when using remote helpers

[Jeff King <peff@peff.net>]

On Thu, May 16, 2019 at 05:35:19PM +0900, Mike Hommey wrote:

> On Wed, May 15, 2019 at 11:28:02PM -0400, Jeff King wrote:
> > Totally orthogonal, but I think we might also want to introduce a helper
> > capability so that import helpers can say "I always send 'done' to
> > fast-import". And then we can pass "--done" to fast-import, which means
> > it would detect a truncated stream.
> 
> Doubly orthogonal, but I wouldn't mind a helper capability that allows
> import helpers to deal with creating git objects on their own rather
> than having a fast-import spawned (git-cinnabar actually doesn't use the
> fast-import stream it's offered to use, but can't be a fetch helper
> either)

Yeah, while writing that I definitely thought "Gee, wouldn't it be
easier if the importer was just responsible for running fast-import
itself?".

What makes it impossible to run as a normal fetch-helper? Is it that we
expect the helper to then report back the refs for us to update?

So I take it your strategy is to just run your own fast-import, and then
you just pass along EOF with no input to the one that Git runs, to
signal that you're done importing? So maybe the right capability is to
let the helper say "by the way, I don't need you to run fast-import for
me". But it's probably not that big a deal, since it's just wasting an
extra process startup.

-Peff