From: Cornelius Weig <cornelius.weig@xxxxxxxxxxx>
When tags are created with `--create-reflog` or with the option
`core.logAllRefUpdates` set to 'always', a reflog is created for them.
So far, the description of reflog entries for tags was empty, making the
reflog hard to understand. For example:
"6e3a7b3 refs/tags/tag_with_reflog@{0}:"
Now, a reflog message is generated when creating a tag. The message
follows the pattern "commit: <subject>" where the subject is taken from
the commit the tag points to. For example:
"6e3a7b3 refs/tags/tag_with_reflog@{0}: commit: Git 2.12-rc0"
If the tag points to a tree/blob/tag object, the following static
messages are used instead:
- "tree object"
- "blob object"
- "other tag object"
Signed-off-by: Cornelius Weig <cornelius.weig@xxxxxxxxxxx>
---
Notes:
While playing around with tag reflogs I also found a bug that was present
before this patch. It manifests itself when the sha1-ref in the reflog does not
point to a commit object but something else.
For example,
- when the referenced sha1 is a tag object:
$ git tag --create-reflog -f -m'annotated tag' tag_with_reflog
- when the referenced sha1 is a blob object:
$ git tag --create-reflog -f tag_with_reflog HEAD:<filename>
- when the referenced sha1 is a tree object:
$ git tag --create-reflog -f tag_with_reflog HEAD^{tree}
In each case, a proper reflog entry is generated, but
$ git reflog tag_with_reflog
will sometimes segfault (if it does, it does so consistently), or only show the
first few entries. The tree/blob cases are IMHO not so important, but the
broken reflog for annotated tags I find quite severe.
I guess it's because the reflog is funneled through the log.c code, where every
reflog-entry is assumed to be a commit object? If this is the case, a fix would
probably be quite involved.
builtin/tag.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
t/t7004-tag.sh | 14 +++++++++++++-
2 files changed, 55 insertions(+), 2 deletions(-)
diff --git a/builtin/tag.c b/builtin/tag.c
index e40c4a9..c0d9478 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -302,6 +302,43 @@ static void create_tag(const unsigned char *object, const char *tag,
}
}
+static void create_reflog_msg(const unsigned char *object, struct strbuf *sb)
+{
+ enum object_type type;
+ char *buf;
+ unsigned long size;
+ int subject_len = 0;
+ const char *subject_start;
+
+ type = sha1_object_info(object, NULL);
+ switch (type) {
+ default:
+ strbuf_addstr(sb, "internal object");
+ break;
+ case OBJ_COMMIT:
+ strbuf_addstr(sb, "commit: ");
+ buf = read_sha1_file(object, &type, &size);
+ if (buf) {
+ subject_len = find_commit_subject(buf, &subject_start);
+ strbuf_insert(sb, 8, subject_start, subject_len);
+ free(buf);
+ } else {
+ die("commit object %s could not be read",
+ sha1_to_hex(repl));
+ }
+ break;
+ case OBJ_TREE:
+ strbuf_addstr(sb, "tree object");
+ break;
+ case OBJ_BLOB:
+ strbuf_addstr(sb, "blob object");
+ break;
+ case OBJ_TAG:
+ strbuf_addstr(sb, "other tag object");
+ break;
+ }
+}
+
struct msg_arg {
int given;
struct strbuf buf;
@@ -335,6 +372,7 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
{
struct strbuf buf = STRBUF_INIT;
struct strbuf ref = STRBUF_INIT;
+ struct strbuf reflog_msg = STRBUF_INIT;
unsigned char object[20], prev[20];
const char *object_ref, *tag;
struct create_tag_options opt;
@@ -494,6 +532,8 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
else
die(_("Invalid cleanup mode %s"), cleanup_arg);
+ create_reflog_msg(object, &reflog_msg);
+
if (create_tag_object) {
if (force_sign_annotate && !annotate)
opt.sign = 1;
@@ -504,7 +544,7 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
if (!transaction ||
ref_transaction_update(transaction, ref.buf, object, prev,
create_reflog ? REF_FORCE_CREATE_REFLOG : 0,
- NULL, &err) ||
+ reflog_msg.buf, &err) ||
ref_transaction_commit(transaction, &err))
die("%s", err.buf);
ref_transaction_free(transaction);
@@ -514,5 +554,6 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
strbuf_release(&err);
strbuf_release(&buf);
strbuf_release(&ref);
+ strbuf_release(&reflog_msg);
return 0;
}
diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index 072e6c6..0a92b2c 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -83,7 +83,19 @@ test_expect_success 'creating a tag using default HEAD should succeed' '
test_expect_success 'creating a tag with --create-reflog should create reflog' '
test_when_finished "git tag -d tag_with_reflog" &&
git tag --create-reflog tag_with_reflog &&
- git reflog exists refs/tags/tag_with_reflog
+ git reflog exists refs/tags/tag_with_reflog &&
+ git log -1 --format="format:commit: %s%n" > expected &&
+ sed -e "s/^.*\t//" .git/logs/refs/tags/tag_with_reflog > actual &&
+ test_cmp expected actual
+'
+
+test_expect_success 'annotated tag with --create-reflog has correct message' '
+ test_when_finished "git tag -d tag_with_reflog" &&
+ git tag -m "annotated tag" --create-reflog tag_with_reflog &&
+ git reflog exists refs/tags/tag_with_reflog &&
+ git log -1 --format="format:commit: %s%n" > expected &&
+ sed -e "s/^.*\t//" .git/logs/refs/tags/tag_with_reflog > actual &&
+ test_cmp expected actual
'
test_expect_success '--create-reflog does not create reflog on failure' '
--
2.10.2