[PATCH 1/9] stream_blob_to_fd: detect errors reading from stream

From: Jeff King <peff@peff.net>
To: git@vger.kernel.org
Cc: Junio C Hamano <gitster@pobox.com>
Subject: [PATCH 1/9] stream_blob_to_fd: detect errors reading from stream
Date: Mon, 25 Mar 2013 16:16:50 -0400	[thread overview]
Message-ID: <20130325201650.GA16019@sigill.intra.peff.net> (raw)
In-Reply-To: <20130325201427.GA15798@sigill.intra.peff.net>

We call read_istream, but never check its return value for
errors. This can lead to us looping infinitely, as we just
keep trying to write "-1" bytes (and we do not notice the
error, as we simply check that write_in_full reports the
same number of bytes we fed it, which of course is also -1).

Signed-off-by: Jeff King <peff@peff.net>
---
No test yet, as my method for triggering this causes _another_ infinite
loop. So the test comes after the fixes, to avoid infinite loops when
bisecting the history later. :)

 streaming.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/streaming.c b/streaming.c
index 4d978e5..f4126a7 100644
--- a/streaming.c
+++ b/streaming.c
@@ -514,6 +514,8 @@ int stream_blob_to_fd(int fd, unsigned const char *sha1, struct stream_filter *f
 		ssize_t wrote, holeto;
 		ssize_t readlen = read_istream(st, buf, sizeof(buf));
 
+		if (readlen < 0)
+			goto close_and_exit;
 		if (!readlen)
 			break;
 		if (can_seek && sizeof(buf) == readlen) {
-- 
1.8.2.13.g0f18d3c
