[PATCH 6/8] refs: fix identity for migrated reflogs

[Patrick Steinhardt <ps@pks.im>]

When migrating reflog entries between different storage formats we must
reconstruct the identity of reflog entries. This is done by passing the
committer passed to the `migrate_one_reflog_entry()` callback function
to `fmt_ident()`.

This results in an invalid identity though: `fmt_ident()` expects the
caller to provide both name and mail of the author, but we pass the full
identity as mail. This leads to an identity like:

    pks <Patrick Steinhardt ps@pks.im>

Fix the bug by splitting the identity line first. This allows us to
extract both the name and mail so that we can pass them to `fmt_ident()`
separately.

This commit does not yet add any tests as there is another bug in the
reflog migration that will be fixed in a subsequent commit. Once that
bug is fixed we'll make the reflog verification in t1450 stricter, and
that will catch both this bug here and the other bug.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 refs.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/refs.c b/refs.c
index 188989e4113..64544300dc3 100644
--- a/refs.c
+++ b/refs.c
@@ -2945,7 +2945,7 @@ struct migration_data {
 	struct ref_store *old_refs;
 	struct ref_transaction *transaction;
 	struct strbuf *errbuf;
-	struct strbuf sb;
+	struct strbuf sb, name, mail;
 };
 
 static int migrate_one_ref(const char *refname, const char *referent UNUSED, const struct object_id *oid,
@@ -2984,7 +2984,7 @@ struct reflog_migration_data {
 	struct ref_store *old_refs;
 	struct ref_transaction *transaction;
 	struct strbuf *errbuf;
-	struct strbuf *sb;
+	struct strbuf *sb, *name, *mail;
 };
 
 static int migrate_one_reflog_entry(struct object_id *old_oid,
@@ -2994,13 +2994,22 @@ static int migrate_one_reflog_entry(struct object_id *old_oid,
 				    const char *msg, void *cb_data)
 {
 	struct reflog_migration_data *data = cb_data;
+	struct ident_split ident;
 	const char *date;
 	int ret;
 
+	if (split_ident_line(&ident, committer, strlen(committer)) < 0)
+		return -1;
+
+	strbuf_reset(data->name);
+	strbuf_add(data->name, ident.name_begin, ident.name_end - ident.name_begin);
+	strbuf_reset(data->mail);
+	strbuf_add(data->mail, ident.mail_begin, ident.mail_end - ident.mail_begin);
+
 	date = show_date(timestamp, tz, DATE_MODE(NORMAL));
 	strbuf_reset(data->sb);
 	/* committer contains name and email */
-	strbuf_addstr(data->sb, fmt_ident("", committer, WANT_BLANK_IDENT, date, 0));
+	strbuf_addstr(data->sb, fmt_ident(data->name->buf, data->mail->buf, WANT_BLANK_IDENT, date, 0));
 
 	ret = ref_transaction_update_reflog(data->transaction, data->refname,
 					    new_oid, old_oid, data->sb->buf,
@@ -3017,6 +3026,8 @@ static int migrate_one_reflog(const char *refname, void *cb_data)
 		.transaction = migration_data->transaction,
 		.errbuf = migration_data->errbuf,
 		.sb = &migration_data->sb,
+		.name = &migration_data->name,
+		.mail = &migration_data->mail,
 	};
 
 	return refs_for_each_reflog_ent(migration_data->old_refs, refname,
@@ -3115,6 +3126,8 @@ int repo_migrate_ref_storage_format(struct repository *repo,
 	struct strbuf new_gitdir = STRBUF_INIT;
 	struct migration_data data = {
 		.sb = STRBUF_INIT,
+		.name = STRBUF_INIT,
+		.mail = STRBUF_INIT,
 	};
 	int did_migrate_refs = 0;
 	int ret;
@@ -3290,6 +3303,8 @@ int repo_migrate_ref_storage_format(struct repository *repo,
 	ref_transaction_free(transaction);
 	strbuf_release(&new_gitdir);
 	strbuf_release(&data.sb);
+	strbuf_release(&data.name);
+	strbuf_release(&data.mail);
 	return ret;
 }
 

-- 
2.50.1.465.gcb3da1c9e6.dirty