[PATCH 5/5] fast-import: stop using lock_ref_sha1

[Jeff King <peff@peff.net>]

We can use lock_any_ref_for_update instead. Besides being
more flexible, the only difference between the two is that
lock_ref_sha1 does not allow "top-level" refs like
"refs/foo" to be updated. However, we know that we do not
have such a ref, because we explicitly add the "tags/"
prefix ourselves.

Note that we now must feed the whole name "refs/tags/X"
instead of just "tags/X" to the function. As a result, our
failure error message is uses the longer name. This is
probably a good thing, though.

As an interesting side note, if we forgot to switch this
input to the function, the tests do not currently catch it.
We import a tag "X" and then check that we can access it at
"tags/X". If we accidentally created "tags/X" at the
top-level $GIT_DIR instead of under "refs/", we would still
find it due to our ref lookup procedure!

We do not make such a mistake in this patch, of course, but
while we're thinking about it, let's make the fast-import
tests more robust by checking for fully qualified
refnames.

Signed-off-by: Jeff King <peff@peff.net>
---
As I mentioned, I'd be OK with dropping this one in favor of just
waiting for Ronnie's transaction patches to graduate.

 fast-import.c          | 4 ++--
 t/t9300-fast-import.sh | 8 ++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/fast-import.c b/fast-import.c
index a1479e9..04a85a4 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -1738,8 +1738,8 @@ static void dump_tags(void)
 
 	for (t = first_tag; t; t = t->next_tag) {
 		strbuf_reset(&ref_name);
-		strbuf_addf(&ref_name, "tags/%s", t->name);
-		lock = lock_ref_sha1(ref_name.buf, NULL);
+		strbuf_addf(&ref_name, "refs/tags/%s", t->name);
+		lock = lock_any_ref_for_update(ref_name.buf, NULL, 0, NULL);
 		if (!lock || write_ref_sha1(lock, t->sha1, msg) < 0)
 			failure |= error("Unable to update %s", ref_name.buf);
 	}
diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index 5fc9ef2..f4c6673 100755
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -153,7 +153,7 @@ tag series-A
 An annotated tag without a tagger
 EOF
 test_expect_success 'A: verify tag/series-A' '
-	git cat-file tag tags/series-A >actual &&
+	git cat-file tag refs/tags/series-A >actual &&
 	test_cmp expect actual
 '
 
@@ -165,7 +165,7 @@ tag series-A-blob
 An annotated tag that annotates a blob.
 EOF
 test_expect_success 'A: verify tag/series-A-blob' '
-	git cat-file tag tags/series-A-blob >actual &&
+	git cat-file tag refs/tags/series-A-blob >actual &&
 	test_cmp expect actual
 '
 
@@ -232,8 +232,8 @@ EOF
 test_expect_success \
 	'A: tag blob by sha1' \
 	'git fast-import <input &&
-	git cat-file tag tags/series-A-blob-2 >actual &&
-	git cat-file tag tags/series-A-blob-3 >>actual &&
+	git cat-file tag refs/tags/series-A-blob-2 >actual &&
+	git cat-file tag refs/tags/series-A-blob-3 >>actual &&
 	test_cmp expect actual'
 
 test_tick
-- 
2.1.0.346.ga0367b9