From eb398797cdc97aae15419f5ac1316440936c31f1 Mon Sep 17 00:00:00 2001 From: Jonathan Tan Date: Fri, 9 Sep 2016 10:36:30 -0700 Subject: connect: advertized capability is not a ref When cloning an empty repository served by standard git, "git clone" produces the following reassuring message: $ git clone git://localhost/tmp/empty Cloning into 'empty'... warning: You appear to have cloned an empty repository. Checking connectivity... done. Meanwhile when cloning an empty repository served by JGit, the output is more haphazard: $ git clone git://localhost/tmp/empty Cloning into 'empty'... Checking connectivity... done. warning: remote HEAD refers to nonexistent ref, unable to checkout. This is a common command to run immediately after creating a remote repository as preparation for adding content to populate it and pushing. The warning is confusing and needlessly worrying. The cause is that, since v3.1.0.201309270735-rc1~22 (Advertise capabilities with no refs in upload service., 2013-08-08), JGit's ref advertisement includes a ref named capabilities^{} to advertise its capabilities on, while git's ref advertisement is empty in this case. This allows the client to learn about the server's capabilities and is needed, for example, for fetch-by-sha1 to work when no refs are advertised. This also affects "ls-remote". For example, against an empty repository served by JGit: $ git ls-remote git://localhost/tmp/empty 0000000000000000000000000000000000000000 capabilities^{} Git advertises the same capabilities^{} ref in its ref advertisement for push but since it never did so for fetch, the client didn't need to handle this case. Handle it. Signed-off-by: Jonathan Tan Helped-by: Jonathan Nieder Signed-off-by: Junio C Hamano --- connect.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'connect.c') diff --git a/connect.c b/connect.c index 067cf409a8..5ccbd1041e 100644 --- a/connect.c +++ b/connect.c @@ -123,6 +123,7 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len, * response does not necessarily mean an ACL problem, though. */ int saw_response; + int got_dummy_ref_with_capabilities_declaration = 0; *list = NULL; for (saw_response = 0; ; saw_response = 1) { @@ -172,8 +173,21 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len, continue; } + if (!strcmp(name, "capabilities^{}")) { + if (saw_response) + die("protocol error: unexpected capabilities^{}"); + if (got_dummy_ref_with_capabilities_declaration) + die("protocol error: multiple capabilities^{}"); + got_dummy_ref_with_capabilities_declaration = 1; + continue; + } + if (!check_ref(name, flags)) continue; + + if (got_dummy_ref_with_capabilities_declaration) + die("protocol error: unexpected ref after capabilities^{}"); + ref = alloc_ref(buffer + GIT_SHA1_HEXSZ + 1); oidcpy(&ref->old_oid, &old_oid); *list = ref; -- cgit v1.2.1