[PATCH] smart-http: Don't deadlock on server failure

From: Shawn O. Pearce <spearce@spearce.org>
Date: Aug 6, 2010, 21:19 UTC
Message-ID: <1281129584-18781-1-git-send-email-spearce@spearce.org>

If the remote HTTP server fails (e.g. returns 404 or 500) when we posted the RPC to it, we won't have sent anything to the background Git process that is supposed to handle the stream. Because we didn't send anything, its waiting for input from remote-curl, and remote-curl cannot read its response payload because doing so would lead to a deadlock.

Send the background task EOF on its input before we try to read its response back, that way it will break out of its read loop and terminate.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---

 This was found in Git 1.6.6.1, and exists since we added smart HTTP
 in 1.6.6.  Should apply at least to 'maint', if not older... :-)

 remote-curl.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/remote-curl.c b/remote-curl.c
index 8f169dd..c9d8f60 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -491,11 +491,12 @@ static int rpc_service(struct rpc_state *rpc, struct discovery *heads)
 		rpc->len = n;
 		err |= post_rpc(rpc);
 	}
-	strbuf_read(&rpc->result, client.out, 0);
 
 	close(client.in);
-	close(client.out);
 	client.in = -1;
+	strbuf_read(&rpc->result, client.out, 0);
+
+	close(client.out);
 	client.out = -1;
 
 	err |= finish_command(&client);

-- 
1.7.2.1.52.g7f7860