[PATCH 24/29] ref_transaction_update(): check refname_is_safe() at a minimum

[Michael Haggerty <mhagger@alum.mit.edu>]

If the user has asked that a new value be set for a reference, we use
check_refname_format() to verify that the reference name satisfies all
of the rules. But in other cases, at least check that refname_is_safe().

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
There are remaining problems in this area of the code. For example,
check_refname_format() is *less* strict than refname_is_safe(). It
allows almost arbitrary top-level reference names like "foo" and
"refs". (The latter is especially fun because if you manage to create
a reference called "refs", Git stops recognizing the directory as a
Git repository.) On the other hand, some callers call
check_refname_format() with incomplete reference names (e.g., branch
names like "master"), so the functions can't be made stricter until
those callers are changed.

I'll address these problems separately if I find the time.

 refs.c                  | 5 +++--
 t/t1400-update-ref.sh   | 2 +-
 t/t1430-bad-ref-name.sh | 2 +-
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/refs.c b/refs.c
index 858b6d7..41eb9e2 100644
--- a/refs.c
+++ b/refs.c
@@ -802,8 +802,9 @@ int ref_transaction_update(struct ref_transaction *transaction,
 	if ((flags & REF_ISPRUNING) && !(flags & REF_NODEREF))
 		die("BUG: REF_ISPRUNING set without REF_NODEREF");
 
-	if (new_sha1 && !is_null_sha1(new_sha1) &&
-	    check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
+	if ((new_sha1 && !is_null_sha1(new_sha1)) ?
+	    check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
+	    !refname_is_safe(refname)) {
 		strbuf_addf(err, "refusing to update ref with bad name '%s'",
 			    refname);
 		return -1;
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index 40b0cce..08bd8fd 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -23,7 +23,7 @@ test_expect_success setup '
 m=refs/heads/master
 n_dir=refs/heads/gu
 n=$n_dir/fixes
-outside=foo
+outside=refs/foo
 
 test_expect_success \
 	"create $m" \
diff --git a/t/t1430-bad-ref-name.sh b/t/t1430-bad-ref-name.sh
index 25ddab4..8937e25 100755
--- a/t/t1430-bad-ref-name.sh
+++ b/t/t1430-bad-ref-name.sh
@@ -285,7 +285,7 @@ test_expect_success 'update-ref -d cannot delete non-ref in .git dir' '
 	echo precious >expect &&
 	test_must_fail git update-ref -d my-private-file >output 2>error &&
 	test_must_be_empty output &&
-	test_i18ngrep -e "cannot lock .*: unable to resolve reference" error &&
+	test_i18ngrep -e "refusing to update ref with bad name" error &&
 	test_cmp expect .git/my-private-file
 '
 
-- 
2.8.1