index-pack: distinguish missing objects from type errors

When we fetch a pack that does not contain an object we
expected to receive, we get an error like:

$ git init --bare tmp.git && cd tmp.git
$ git fetch ../parent.git
[...]
error: Could not read 964953ec7bcc0245cb1d0db4095455edd21a2f2e
fatal: Failed to traverse parents of commit b8247b40caf6704fe52736cdece6d6aae87471aa
error: ../parent.git did not send all necessary objects

This comes from the check_everything_connected rev-list. If
we try cloning the same repo (rather than a fetch), we end
up using index-pack's --check-self-contained-and-connected
option instead, which produces output like:

$ git clone --no-local --bare parent.git tmp.git
[...]
fatal: object of unexpected type
fatal: index-pack failed

Not only is the sha1 missing, but it's a misleading message.
There's no type problem, but rather a missing object
problem; we don't notice the difference because we simply
compare OBJ_BAD != OBJ_BLOB.  Let's provide a different
message for this case:

$ git clone --no-local --bare parent.git tmp.git
fatal: did not receive expected object 6b00a8c61ed379d5f925a72c1987c9c52129d364
fatal: index-pack failed

While we're at it, let's also improve a true type mismatch
error to look like

fatal: object 6b00a8c61ed379d5f925a72c1987c9c52129d364: expected type blob, got tree

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index fa74972886cc8e6c0f6308e28de26a13cae6a2b7..7878836eb45ceffa76f348384b502d882e163a76 100644 (file)
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -200,8 +200,13 @@ static unsigned check_object(struct object *obj)
        if (!(obj->flags & FLAG_CHECKED)) {
                unsigned long size;
                int type = sha1_object_info(obj->sha1, &size);
-               if (type != obj->type || type <= 0)
-                       die(_("object of unexpected type"));
+               if (type <= 0)
+                       die(_("did not receive expected object %s"),
+                             sha1_to_hex(obj->sha1));
+               if (type != obj->type)
+                       die(_("object %s: expected type %s, found %s"),
+                           sha1_to_hex(obj->sha1),
+                           typename(obj->type), typename(type));
                obj->flags |= FLAG_CHECKED;
                return 1;
        }