Add support for negative refs

From: Linus Torvalds <torvalds@osdl.org>
Date: Sep 12, 2006, 03:10 UTC
Message-ID: <Pine.LNX.4.64.0609112008500.27779@g5.osdl.org>
In-Reply-To: <Pine.LNX.4.64.0609111632050.27779@g5.osdl.org>

You can remove a ref that is packed two different ways: either simply repack all the refs without that one, or create a loose ref that has the magic all-zero SHA1.

This also adds back the test that a ref actually has the object it points to.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

This one is trivial, and obviously depends on the previous series.

I'm sending it just because I have a much bigger cleanup that I'd _really_ like to go in, and I did this trivial one before that much more interesting one.

diff --git a/refs.c b/refs.c
index 5f80a68..72e2283 100644
--- a/refs.c
+++ b/refs.c
@@ -280,6 +280,12 @@ static int do_for_each_ref(const char *b
 		}
 		if (strncmp(base, entry->name, trim))
 			continue;
+		if (is_null_sha1(entry->sha1))
+			continue;
+		if (!has_sha1_file(entry->sha1)) {
+			error("%s does not point to a valid object!", entry->name);
+			continue;
+		}
 		retval = fn(entry->name + trim, entry->sha1);
 		if (retval)
 			return retval;