[PATCH] clone: check if server supports shallow clones

[Mike Edgar <adgar@google.com>]

When the user passes --depth to git-clone the server's capabilities are
not currently consulted. The client will send shallow requests even if
the server does not understand them, and the resulting error may be
unhelpful to the user. This change pre-emptively checks so git-clone can
exit with a helpful error if necessary.

Signed-off-by: Mike Edgar <adgar@google.com>
---
 builtin/clone.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/builtin/clone.c b/builtin/clone.c
index b878252..b4e9846 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -944,6 +944,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	refs = transport_get_remote_refs(transport);
 
+	if (option_depth && !is_local && !server_supports("shallow"))
+		die(_("Server does not support shallow clients"));
+
 	if (refs) {
 		mapped_refs = wanted_peer_refs(refs, refspec);
 		/*
-- 
2.2.0.rc0.207.ga3a616c