fast-import: don't allow to note on empty branch

'reset' command makes fast-import start a branch from scratch. It's name
is kept in lookup table but it's sha1 is null_sha1 (special value).
'notemodify' command can be used to add a note on branch head given it's
name. lookup_branch() is used it that case and it doesn't check for
null_sha1. So fast-import writes a note for null_sha1 object instead of
giving a error.

Add a check to deny adding a note on empty branch and add a corresponding
test.

Signed-off-by: Dmitry Ivankov <divanorama@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/fast-import.c b/fast-import.c
index c44cc11fd7994fd4591bc7e445777da376d481d1..a8a3ad1124bf9220942de5c2887fb68c54e16219 100644 (file)
--- a/fast-import.c
+++ b/fast-import.c
@@ -2416,6 +2416,8 @@ static void note_change_n(struct branch *b, unsigned char old_fanout)
        /* <committish> */
        s = lookup_branch(p);
        if (s) {
+               if (is_null_sha1(s->sha1))
+                       die("Can't add a note on empty branch.");
                hashcpy(commit_sha1, s->sha1);
        } else if (*p == ':') {
                uintmax_t commit_mark = strtoumax(p + 1, NULL, 10);

diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index 0b97d7aab92b1531de04fe5cd43402940efc0f3e..bd32b91d8f8807fa16763d905b1ad667bbe1836c 100755 (executable)
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -1987,6 +1987,23 @@ test_expect_success \
        'Q: verify second note for second commit' \
        'git cat-file blob refs/notes/foobar:$commit2 >actual && test_cmp expect actual'
 
+cat >input <<EOF
+reset refs/heads/Q0
+
+commit refs/heads/note-Q0
+committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+data <<COMMIT
+Note for an empty branch.
+COMMIT
+
+N inline refs/heads/Q0
+data <<NOTE
+some note
+NOTE
+EOF
+test_expect_success \
+       'Q: deny note on empty branch' \
+       'test_must_fail git fast-import <input'
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 ### series R (feature and option)
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