Re: [PATCH 1/1] upload-pack: fix race condition in error messages
On Thu, Aug 29, 2019 at 11:58:18PM +0200, SZEDER Gábor wrote:
Show 32 quoted lines
> On Thu, Aug 29, 2019 at 10:38:05AM -0400, Jeff King wrote:
> > So any fixes there have to happen on the client side. I am still
> > confused about why the client is writing in this case, per the argument
> > in 014ade7484 (upload-pack: send ERR packet for non-tip objects,
> > 2019-04-13). It would be nice to use GIT_TRACE_PACKET to see what it's
> > trying to write, but I still haven't been able to reproduce the issue.
>
> It's the "done" line:
>
> + cat trace-packet
> packet: upload-pack> 5e26403b4485d7a44fd8b65dc3f71e21c0dd6fad HEAD\0multi_ack thin-pack side-band side-band-64k ofs-delta shallow deepen-since deepen-not deepen-relative no-progress include-tag multi_ack_detailed allow-tip-sha1-in-want allow-reachable-sha1-in-want symref=HEAD:refs/heads/master agent=git/2.23.0.40.g4d780d4382.dirty
> packet: upload-pack> 5e26403b4485d7a44fd8b65dc3f71e21c0dd6fad refs/heads/master
> packet: upload-pack> 0000
> packet: fetch< 5e26403b4485d7a44fd8b65dc3f71e21c0dd6fad HEAD\0multi_ack thin-pack side-band side-band-64k ofs-delta shallow deepen-since deepen-not deepen-relative no-progress include-tag multi_ack_detailed allow-tip-sha1-in-want allow-reachable-sha1-in-want symref=HEAD:refs/heads/master agent=git/2.23.0.40.g4d780d4382.dirty
> packet: fetch< 5e26403b4485d7a44fd8b65dc3f71e21c0dd6fad refs/heads/master
> packet: fetch< 0000
> packet: fetch> want 64ea4c133d59fa98e86a771eda009872d6ab2886 multi_ack_detailed side-band-64k thin-pack no-progress ofs-delta deepen-since deepen-not agent=git/2.23.0.40.g4d780d4382.dirty
> packet: fetch> 0000
> packet: upload-pack< want 64ea4c133d59fa98e86a771eda009872d6ab2886 multi_ack_detailed side-band-64k thin-pack no-progress ofs-delta deepen-since deepen-not agent=git/2.23.0.40.g4d780d4382.dirty
> packet: upload-pack< 0000
> packet: upload-pack> ERR upload-pack: not our ref 64ea4c133d59fa98e86a771eda009872d6ab2886
> packet: upload-pack> 0000
> packet: fetch> done
>
> In the avarage successful run that "fetch> done" pkt-line is
> immediately after the "fetch> 0000".
>
> The above is on my Linux box; here is a failure on macOS, essentially
> the same:
>
> https://travis-ci.org/szeder/git/jobs/578555606#L3453
>
Try this patch to reliably reproduce this failure:
diff --git a/fetch-pack.c b/fetch-pack.c
index 65be043f2a..e18864458b 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -471,6 +471,7 @@ static int find_common(struct fetch_negotiator *negotiator,
}
done:
if (!got_ready || !no_done) {
+ sleep(1);
packet_buf_write(&req_buf, "done\n");
send_request(args, fd[1], &req_buf);
}
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index c81ca360ac..ebecc81c89 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1252,7 +1252,9 @@ do
git fetch ../testrepo/.git $SHA1_2 &&
git cat-file commit $SHA1_2 &&
test_must_fail env GIT_TEST_PROTOCOL_VERSION= \
+ GIT_TRACE_PACKET="$(pwd)/trace-packet" \
git fetch ../testrepo/.git $SHA1_3 2>err &&
+ cat trace-packet &&
test_i18ngrep "remote error:.*not our ref.*$SHA1_3\$" err
)
'
SZEDER Gábor <szeder.dev@gmail.com>