Re: Question about 'branch -d' safety
On Sun, Jul 11, 2010 at 09:16:26AM +0200, Jakub Narebski wrote:
Show 7 quoted lines
>
> The problem is, that when you have 'foo/bar' branch, then you have
> 'foo/bar' reflog. When you delete branch 'foo/bar', but do not delete
> 'foo/bar' reflog (only add to it branch deletion event), and then you
> want to create 'foo' branch, git wouldn't be able to create reflog
> fo 'foo' because of directory / file (D/F) conflict: there is 'foo/'
> directory preventing file 'foo' from being created.
Right, of course. So how about this?
Clemens
-->o--
Date: Sun, 11 Jul 2010 12:37:06 +0200
Subject: [PATCH/RFC] graveyard for reflogs
Instead of removing reflogs together with refs, keep them around and reuse them as a starting point, if a ref of the same name is created again.
When a ref is deleted, a ~ is appended to each directory of the corresponding reflog entry, e.g., refs/heads/branch is renamed to refs~/heads~/branch. Since ~ must not be used for ref names, directory/file conflicts are thus avoided.
Known issues:
- The reflog cannot be accessed while the ref does not exist.
- Older git versions will not resurrect the reflog, and therefore
leave the renamed reflog behind.
- Breaks t7701, because git-expire tries to lock log entries,
which fails because ~ is an illegal character for refs.
- Breaks t9300.
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
---
reflog-walk.c | 9 +++++--
refs.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
t/t1450-fsck.sh | 1 +
3 files changed, 73 insertions(+), 4 deletions(-)
diff --git a/reflog-walk.c b/reflog-walk.c
index 4879615..9415ac8 100644
--- a/reflog-walk.c
+++ b/reflog-walk.c
@@ -228,15 +228,18 @@ void fake_reflog_parent(struct reflog_walk_info *info, struct commit *commit)
return;
}
- reflog = &commit_reflog->reflogs->items[commit_reflog->recno];
info->last_commit_reflog = commit_reflog;
commit_reflog->recno--;
- commit_info->commit = (struct commit *)parse_object(reflog->osha1);
- if (!commit_info->commit) {
+ if (commit_reflog->recno < 0) {
commit->parents = NULL;
return;
}
+ reflog = &commit_reflog->reflogs->items[commit_reflog->recno];
+ commit_info->commit = (struct commit *)parse_object(reflog->nsha1);
+ if (!commit_info->commit)
+ die("Invalid reflog entry");
+
commit->parents = xcalloc(sizeof(struct commit_list), 1);
commit->parents->item = commit_info->commit;
commit->object.flags &= ~(ADDED | SEEN | SHOWN);
diff --git a/refs.c b/refs.c
index b540067..78c48ad 100644
--- a/refs.c
+++ b/refs.c
@@ -1052,6 +1052,70 @@ static int repack_without_ref(const char *refname)
return commit_lock_file(&packlock);
}
+static void pronounce_dead(struct strbuf *dead_ref, const char *ref)
+{
+ const char *p = ref;
+ while (*p) {
+ if (*p == '/') {
+ int len = p - ref;
+ strbuf_add(dead_ref, ref, len);
+ if (len > 0)
+ strbuf_addstr(dead_ref, "~/");
+ ref = p + 1;
+ }
+ p++;
+ }
+ strbuf_addstr(dead_ref, ref);
+}
+
+static int bury_log(const char *ref)
+{
+ struct strbuf dead_ref = STRBUF_INIT;
+ struct stat loginfo;
+
+ if (lstat(git_path("logs/%s", ref), &loginfo))
+ return 0;
+
+ pronounce_dead(&dead_ref, ref);
+
+ if (S_ISLNK(loginfo.st_mode))
+ return error("reflog for %s is a symlink", ref);
+
+ if (safe_create_leading_directories(git_path("logs/%s", dead_ref.buf)))
+ return error("unable to create directory for %s", dead_ref.buf);
+
+ if (rename(git_path("logs/%s", ref), git_path("logs/%s", dead_ref.buf)))
+ return error("unable to move logfile to logs/%s: %s",
+ dead_ref.buf, strerror(errno));
+
+ strbuf_release(&dead_ref);
+ return 0;
+}
+
+static int resurrect_log(const char *ref)
+{
+ struct strbuf dead_ref = STRBUF_INIT;
+ struct stat loginfo;
+
+ pronounce_dead(&dead_ref, ref);
+
+ if (lstat(git_path("logs/%s", dead_ref.buf), &loginfo))
+ return 0;
+
+ if (S_ISLNK(loginfo.st_mode))
+ return error("reflog for %s is a symlink", dead_ref.buf);
+
+ if (safe_create_leading_directories(git_path("logs/%s", ref)))
+ return error("unable to create directory for %s", ref);
+
+ if (rename(git_path("logs/%s", dead_ref.buf), git_path("logs/%s", ref)))
+ return error("unable to move logfile to logs/%s: %s",
+ ref, strerror(errno));
+
+ strbuf_release(&dead_ref);
+ return 0;
+}
+
int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
{
struct ref_lock *lock;
@@ -1084,7 +1148,7 @@ int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
*/
ret |= repack_without_ref(refname);
- unlink_or_warn(git_path("logs/%s", lock->ref_name));
+ bury_log(lock->ref_name);
invalidate_cached_refs();
unlock_ref(lock);
return ret;
@@ -1384,6 +1448,7 @@ int write_ref_sha1(struct ref_lock *lock,
unlock_ref(lock);
return -1;
}
+ resurrect_log(lock->ref_name);
invalidate_cached_refs();
if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
(strcmp(lock->ref_name, lock->orig_ref_name) &&
diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index 759cf12..65f160e 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -55,6 +55,7 @@ test_expect_success 'object with bad sha1' '
grep "$sha.*corrupt" out &&
rm -f .git/objects/$new &&
git update-ref -d refs/heads/bogus &&
+ rm -f .git/logs/refs~/heads~/bogus &&
git read-tree -u --reset HEAD
'
--
1.7.1.571.gba4d01
Nanako Shiraishi
