Re: [PATCH] upload-pack: Use finish_{command,async}() instead of waitpid().

Johannes Sixt [off-list ref] writes:

- If pack-objects sees an error, it terminates with failure. Since this
  breaks the pipe to rev-list, rev-list is killed with SIGPIPE.

I was a bit uneasy about this part.  We do not explicitly tell
rev-list not to ignore SIGPIPE, so it could spin fruitlessly
listing revs and calling write(2).  But the error from that
write should already be handled correctly anyway, so this should
be Ok.

	The test case checks for failures in rev-list (a missing
	object). Any hints how to trigger a failure in pack-objects
	that does not also trigger in rev-list would be welcome.

How about removing a blob from the test repository  to corrupt
it?  rev-list --objects I think would happily list the blob
because it sees its name in its containing tree without checking
its existence.