When updating a symref it's currently not possible to know for sure what
was the previous value that was overwritten. Make use of
ref_transaction's atomicity and record the previous value there. Add
a new variable to refs_update_symref's signature to be able to pass this
information back up to callers.
Signed-off-by: Bence Ferdinandy <bence@xxxxxxxxxxxxxx>
---
Notes:
v4: new patch
v5: - added before_target to reftables backend
- added an extra safety check for transaction's existence in refs.c
builtin/branch.c | 2 +-
builtin/checkout.c | 4 ++--
builtin/clone.c | 6 +++---
builtin/notes.c | 2 +-
builtin/remote.c | 6 +++---
builtin/symbolic-ref.c | 2 +-
builtin/worktree.c | 2 +-
refs.c | 8 ++++++--
refs.h | 3 ++-
refs/files-backend.c | 1 +
refs/refs-internal.h | 8 ++++++++
refs/reftable-backend.c | 1 +
reset.c | 2 +-
sequencer.c | 2 +-
setup.c | 2 +-
t/helper/test-ref-store.c | 2 +-
16 files changed, 34 insertions(+), 19 deletions(-)
diff --git a/builtin/branch.c b/builtin/branch.c
index fd1611ebf5..6c87690b58 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -559,7 +559,7 @@ static int replace_each_worktree_head_symref(struct worktree **worktrees,
continue;
refs = get_worktree_ref_store(worktrees[i]);
- if (refs_update_symref(refs, "HEAD", newref, logmsg))
+ if (refs_update_symref(refs, "HEAD", newref, logmsg, NULL))
ret = error(_("HEAD of working tree %s is not updated"),
worktrees[i]->path);
}
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 9c30000d3a..356ee9bcde 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1015,7 +1015,7 @@ static void update_refs_for_switch(const struct checkout_opts *opts,
describe_detached_head(_("HEAD is now at"), new_branch_info->commit);
}
} else if (new_branch_info->path) { /* Switch branches. */
- if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", new_branch_info->path, msg.buf) < 0)
+ if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", new_branch_info->path, msg.buf, NULL) < 0)
die(_("unable to update HEAD"));
if (!opts->quiet) {
if (old_branch_info->path && !strcmp(new_branch_info->path, old_branch_info->path)) {
@@ -1479,7 +1479,7 @@ static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
die(_("You are on a branch yet to be born"));
strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
status = refs_update_symref(get_main_ref_store(the_repository),
- "HEAD", branch_ref.buf, "checkout -b");
+ "HEAD", branch_ref.buf, "checkout -b", NULL);
strbuf_release(&branch_ref);
if (!opts->quiet)
fprintf(stderr, _("Switched to a new branch '%s'\n"),
diff --git a/builtin/clone.c b/builtin/clone.c
index e77339c847..ead2af20ea 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -661,7 +661,7 @@ static void update_remote_refs(const struct ref *refs,
strbuf_addstr(&head_ref, "HEAD");
if (refs_update_symref(get_main_ref_store(the_repository), head_ref.buf,
remote_head_points_at->peer_ref->name,
- msg) < 0)
+ msg, NULL) < 0)
die(_("unable to update %s"), head_ref.buf);
strbuf_release(&head_ref);
}
@@ -673,7 +673,7 @@ static void update_head(const struct ref *our, const struct ref *remote,
const char *head;
if (our && skip_prefix(our->name, "refs/heads/", &head)) {
/* Local default branch link */
- if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", our->name, NULL) < 0)
+ if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", our->name, NULL, NULL) < 0)
die(_("unable to update HEAD"));
if (!option_bare) {
refs_update_ref(get_main_ref_store(the_repository),
@@ -702,7 +702,7 @@ static void update_head(const struct ref *our, const struct ref *remote,
* Unborn head from remote; same as "our" case above except
* that we have no ref to update.
*/
- if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", unborn, NULL) < 0)
+ if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", unborn, NULL, NULL) < 0)
die(_("unable to update HEAD"));
if (!option_bare)
install_branch_config(0, head, remote_name, unborn);
diff --git a/builtin/notes.c b/builtin/notes.c
index 8c26e45526..ba646f06ff 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -980,7 +980,7 @@ static int merge(int argc, const char **argv, const char *prefix)
die(_("a notes merge into %s is already in-progress at %s"),
notes_ref, wt->path);
free_worktrees(worktrees);
- if (refs_update_symref(get_main_ref_store(the_repository), "NOTES_MERGE_REF", notes_ref, NULL))
+ if (refs_update_symref(get_main_ref_store(the_repository), "NOTES_MERGE_REF", notes_ref, NULL, NULL))
die(_("failed to store link to current notes ref (%s)"),
notes_ref);
fprintf(stderr, _("Automatic notes merge failed. Fix conflicts in %s "
diff --git a/builtin/remote.c b/builtin/remote.c
index 76670ddd8b..d8ff440027 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -244,7 +244,7 @@ static int add(int argc, const char **argv, const char *prefix)
strbuf_reset(&buf2);
strbuf_addf(&buf2, "refs/remotes/%s/%s", name, master);
- if (refs_update_symref(get_main_ref_store(the_repository), buf.buf, buf2.buf, "remote add"))
+ if (refs_update_symref(get_main_ref_store(the_repository), buf.buf, buf2.buf, "remote add", NULL))
result = error(_("Could not setup master '%s'"), master);
}
@@ -864,7 +864,7 @@ static int mv(int argc, const char **argv, const char *prefix)
strbuf_reset(&buf3);
strbuf_addf(&buf3, "remote: renamed %s to %s",
item->string, buf.buf);
- if (refs_update_symref(get_main_ref_store(the_repository), buf.buf, buf2.buf, buf3.buf))
+ if (refs_update_symref(get_main_ref_store(the_repository), buf.buf, buf2.buf, buf3.buf, NULL))
die(_("creating '%s' failed"), buf.buf);
display_progress(progress, ++refs_renamed_nr);
}
@@ -1444,7 +1444,7 @@ static int set_head(int argc, const char **argv, const char *prefix)
/* make sure it's valid */
if (!refs_ref_exists(get_main_ref_store(the_repository), buf2.buf))
result |= error(_("Not a valid ref: %s"), buf2.buf);
- else if (refs_update_symref(get_main_ref_store(the_repository), buf.buf, buf2.buf, "remote set-head"))
+ else if (refs_update_symref(get_main_ref_store(the_repository), buf.buf, buf2.buf, "remote set-head", NULL))
result |= error(_("Could not setup %s"), buf.buf);
else if (opt_a)
printf("%s/HEAD set to %s\n", argv[0], head_name);
diff --git a/builtin/symbolic-ref.c b/builtin/symbolic-ref.c
index 299d23d76a..7728fbc3c1 100644
--- a/builtin/symbolic-ref.c
+++ b/builtin/symbolic-ref.c
@@ -88,7 +88,7 @@ int cmd_symbolic_ref(int argc,
if (check_refname_format(argv[1], REFNAME_ALLOW_ONELEVEL) < 0)
die("Refusing to set '%s' to invalid ref '%s'", argv[0], argv[1]);
ret = !!refs_update_symref(get_main_ref_store(the_repository),
- argv[0], argv[1], msg);
+ argv[0], argv[1], msg, NULL);
break;
default:
usage_with_options(git_symbolic_ref_usage, options);
diff --git a/builtin/worktree.c b/builtin/worktree.c
index fc31d072a6..a7ab4193c1 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -517,7 +517,7 @@ static int add_worktree(const char *path, const char *refname,
ret = refs_update_ref(wt_refs, NULL, "HEAD", &commit->object.oid,
NULL, 0, UPDATE_REFS_MSG_ON_ERR);
else
- ret = refs_update_symref(wt_refs, "HEAD", symref.buf, NULL);
+ ret = refs_update_symref(wt_refs, "HEAD", symref.buf, NULL, NULL);
if (ret)
goto done;
diff --git a/refs.c b/refs.c
index 5f729ed412..91cacee6f9 100644
--- a/refs.c
+++ b/refs.c
@@ -2114,7 +2114,8 @@ int peel_iterated_oid(struct repository *r, const struct object_id *base, struct
}
int refs_update_symref(struct ref_store *refs, const char *ref,
- const char *target, const char *logmsg)
+ const char *target, const char *logmsg,
+ struct strbuf *before_target)
{
struct ref_transaction *transaction;
struct strbuf err = STRBUF_INIT;
@@ -2130,6 +2131,10 @@ int refs_update_symref(struct ref_store *refs, const char *ref,
}
strbuf_release(&err);
+
+ if (transaction && before_target && transaction->updates[0]->before_target)
+ strbuf_addstr(before_target, transaction->updates[0]->before_target);
+
if (transaction)
ref_transaction_free(transaction);
@@ -2948,4 +2953,3 @@ int ref_update_expects_existing_old_ref(struct ref_update *update)
return (update->flags & REF_HAVE_OLD) &&
(!is_null_oid(&update->old_oid) || update->old_target);
}
-
diff --git a/refs.h b/refs.h
index 108dfc93b3..f38616db84 100644
--- a/refs.h
+++ b/refs.h
@@ -571,7 +571,8 @@ int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
const char *newref, const char *logmsg);
int refs_update_symref(struct ref_store *refs, const char *refname,
- const char *target, const char *logmsg);
+ const char *target, const char *logmsg,
+ struct strbuf *before_target);
enum action_on_err {
UPDATE_REFS_MSG_ON_ERR,
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 0824c0b8a9..8415f2d020 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2577,6 +2577,7 @@ static int lock_ref_for_update(struct files_ref_store *refs,
}
update->backend_data = lock;
+ update->before_target = xstrdup_or_null(referent.buf);
if (update->type & REF_ISSYMREF) {
if (update->flags & REF_NO_DEREF) {
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 2313c830d8..7df3e6271e 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -104,6 +104,14 @@ struct ref_update {
*/
const char *old_target;
+ /*
+ * The previous target before applying new_target will be
+ * written here, to be used by callers when they do not want to
+ * check old_target during the transaction, but do want to know
+ * what it was.
+ */
+ const char *before_target;
+
/*
* One or more of REF_NO_DEREF, REF_FORCE_CREATE_REFLOG,
* REF_HAVE_NEW, REF_HAVE_OLD, or backend-specific flags.
diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c
index 3c96fbf66f..32330b6bc6 100644
--- a/refs/reftable-backend.c
+++ b/refs/reftable-backend.c
@@ -1244,6 +1244,7 @@ static int reftable_be_transaction_prepare(struct ref_store *ref_store,
if (ret)
goto done;
}
+ u->before_target = xstrdup_or_null(referent.buf);
}
transaction->backend_data = tx_data;
diff --git a/reset.c b/reset.c
index b22b1be792..cc36a9ed56 100644
--- a/reset.c
+++ b/reset.c
@@ -76,7 +76,7 @@ static int update_refs(const struct reset_head_opts *opts,
if (!ret)
ret = refs_update_symref(get_main_ref_store(the_repository),
"HEAD", switch_to_branch,
- reflog_head);
+ reflog_head, NULL);
}
if (!ret && run_hook)
run_hooks_l(the_repository, "post-checkout",
diff --git a/sequencer.c b/sequencer.c
index 8d01cd50ac..23b162924c 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -5107,7 +5107,7 @@ static int pick_commits(struct repository *r,
}
msg = reflog_message(opts, "finish", "returning to %s",
head_ref.buf);
- if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", head_ref.buf, msg)) {
+ if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", head_ref.buf, msg, NULL)) {
res = error(_("could not update HEAD to %s"),
head_ref.buf);
goto cleanup_head_ref;
diff --git a/setup.c b/setup.c
index 94e79b2e48..d95f051465 100644
--- a/setup.c
+++ b/setup.c
@@ -2275,7 +2275,7 @@ void create_reference_database(enum ref_storage_format ref_storage_format,
die(_("invalid initial branch name: '%s'"),
initial_branch);
- if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", ref, NULL) < 0)
+ if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", ref, NULL, NULL) < 0)
exit(1);
free(ref);
}
diff --git a/t/helper/test-ref-store.c b/t/helper/test-ref-store.c
index 65346dee55..a911302bea 100644
--- a/t/helper/test-ref-store.c
+++ b/t/helper/test-ref-store.c
@@ -120,7 +120,7 @@ static int cmd_create_symref(struct ref_store *refs, const char **argv)
const char *target = notnull(*argv++, "target");
const char *logmsg = *argv++;
- return refs_update_symref(refs, refname, target, logmsg);
+ return refs_update_symref(refs, refname, target, logmsg, NULL);
}
static struct flag_definition transaction_flags[] = {
--
2.47.0.6.g9542df9767
