> -----Original Message----- > From: Jeff King [mailto:peff@xxxxxxxx] > Sent: Monday, November 14, 2016 2:41 PM > To: David Turner > Cc: git@xxxxxxxxxxxxxxx; spearce@xxxxxxxxxxx > Subject: Re: [PATCH] remote-curl: don't hang when a server dies before any > output > > On Mon, Nov 14, 2016 at 01:24:31PM -0500, Jeff King wrote: > > > 2. Have remote-curl understand enough of the protocol that it can > > abort rather than hang. > > > > I think that's effectively the approach of your patch, but for one > > specific case. But could we, for example, make sure that everything > > we proxy is a complete set of pktlines and ends with a flush? And > > if not, then we hang up on fetch-pack. > > > > I _think_ that would work, because even the pack is always encased > > in pktlines for smart-http. > > So something like this. It turned out to be a lot uglier than I had hoped > because we get fed the data from curl in odd-sized chunks, so we need a > state machine. > > But it does seem to work. At least it doesn't seem to break anything in > the test suite, and it fixes the new tests you added. I'd worry that > there's some obscure case where the response isn't packetized in the same > way. Overall, this looks good to me. The state machine is pretty clean. I think I would have used a tiny buffer for the length field, and then I would have regretted it. Your way looks nicer than my unwritten patch would have looked. > +#define READ_ONE_HEX(shift) do { \ > + int val = hexval(buf[0]); \ > + if (val < 0) { \ > + warning("error on %d", *buf); \ > + rpc->pktline_state = RPC_PKTLINE_ERROR; \ > + return; \ > + } \ > + rpc->pktline_len |= val << shift; \ Nit: parenthesize shift here, since it is a parameter to a macro.