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authorKarthik Nayak <karthik.188@gmail.com>2024-06-07 15:33:04 +0200
committerJunio C Hamano <gitster@pobox.com>2024-06-07 10:25:45 -0700
commit7dd4051b014741732271785c0915599b1f0c1a47 (patch)
tree2a89f41d7ffcf0e404d63f14a848131be2a2f7a7 /builtin
parentf1dcdd6deb6bdd57e3e8dad5aa7a3fcc1526b9ec (diff)
downloadgit-7dd4051b014741732271785c0915599b1f0c1a47.tar.gz
update-ref: add support for 'symref-update' command
Add 'symref-update' command to the '--stdin' mode of 'git-update-ref' to allow updates of symbolic refs. The 'symref-update' command takes in a <new-target>, which the <ref> will be updated to. If the <ref> doesn't exist it will be created. It also optionally takes either an `ref <old-target>` or `oid <old-oid>`. If the <old-target> is provided, it checks to see if the <ref> targets the <old-target> before the update. If <old-oid> is provided it checks <ref> to ensure that it is a regular ref and <old-oid> is the OID before the update. This by extension also means that this when a zero <old-oid> is provided, it ensures that the ref didn't exist before. The divergence in syntax from the regular `update` command is because if we don't use a `(ref | oid)` prefix for the old_value, then there is ambiguity around if the value provided should be treated as an oid or a reference. This is more so the reason, because we allow anything committish to be provided as an oid. While 'symref-verify' and 'symref-delete' also take in `<old-target>` we do not have this divergence there as those commands only work with symrefs. Whereas 'symref-update' also works with regular refs and allows users to convert regular refs to symrefs. The command allows users to perform symbolic ref updates within a transaction. This provides atomicity and allows users to perform a set of operations together. This command supports deref mode, to ensure that we can update dereferenced regular refs to symrefs. Helped-by: Patrick Steinhardt <ps@pks.im> Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'builtin')
-rw-r--r--builtin/update-ref.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 989c0ebc5f..d3cfae64ed 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -98,6 +98,42 @@ static char *parse_next_refname(const char **next)
return parse_refname(next);
}
+/*
+ * Wrapper around parse_arg which skips the next delimiter.
+ */
+static char *parse_next_arg(const char **next)
+{
+ struct strbuf arg = STRBUF_INIT;
+
+ if (line_termination) {
+ /* Without -z, consume SP and use next argument */
+ if (!**next || **next == line_termination)
+ return NULL;
+ if (**next != ' ')
+ die("expected SP but got: %s", *next);
+ } else {
+ /* With -z, read the next NUL-terminated line */
+ if (**next)
+ return NULL;
+ }
+ /* Skip the delimiter */
+ (*next)++;
+
+ if (line_termination) {
+ /* Without -z, use the next argument */
+ *next = parse_arg(*next, &arg);
+ } else {
+ /* With -z, use everything up to the next NUL */
+ strbuf_addstr(&arg, *next);
+ *next += arg.len;
+ }
+
+ if (arg.len)
+ return strbuf_detach(&arg, NULL);
+
+ strbuf_release(&arg);
+ return NULL;
+}
/*
* The value being parsed is <old-oid> (as opposed to <new-oid>; the
@@ -237,6 +273,61 @@ static void parse_cmd_update(struct ref_transaction *transaction,
strbuf_release(&err);
}
+static void parse_cmd_symref_update(struct ref_transaction *transaction,
+ const char *next, const char *end)
+{
+ char *refname, *new_target, *old_arg;
+ char *old_target = NULL;
+ struct strbuf err = STRBUF_INIT;
+ struct object_id old_oid;
+ int have_old_oid = 0;
+
+ refname = parse_refname(&next);
+ if (!refname)
+ die("symref-update: missing <ref>");
+
+ new_target = parse_next_refname(&next);
+ if (!new_target)
+ die("symref-update %s: missing <new-target>", refname);
+
+ old_arg = parse_next_arg(&next);
+ if (old_arg) {
+ old_target = parse_next_arg(&next);
+ if (!old_target)
+ die("symref-update %s: expected old value", refname);
+
+ if (!strcmp(old_arg, "oid")) {
+ if (repo_get_oid(the_repository, old_target, &old_oid))
+ die("symref-update %s: invalid oid: %s", refname, old_target);
+
+ have_old_oid = 1;
+ } else if (!strcmp(old_arg, "ref")) {
+ if (check_refname_format(old_target, REFNAME_ALLOW_ONELEVEL))
+ die("symref-update %s: invalid ref: %s", refname, old_target);
+ } else {
+ die("symref-update %s: invalid arg '%s' for old value", refname, old_arg);
+ }
+ }
+
+ if (*next != line_termination)
+ die("symref-update %s: extra input: %s", refname, next);
+
+ if (ref_transaction_update(transaction, refname, NULL,
+ have_old_oid ? &old_oid : NULL,
+ new_target,
+ have_old_oid ? NULL : old_target,
+ update_flags | create_reflog_flag,
+ msg, &err))
+ die("%s", err.buf);
+
+ update_flags = default_flags;
+ free(refname);
+ free(old_arg);
+ free(old_target);
+ free(new_target);
+ strbuf_release(&err);
+}
+
static void parse_cmd_create(struct ref_transaction *transaction,
const char *next, const char *end)
{
@@ -502,6 +593,7 @@ static const struct parse_cmd {
{ "create", parse_cmd_create, 2, UPDATE_REFS_OPEN },
{ "delete", parse_cmd_delete, 2, UPDATE_REFS_OPEN },
{ "verify", parse_cmd_verify, 2, UPDATE_REFS_OPEN },
+ { "symref-update", parse_cmd_symref_update, 4, UPDATE_REFS_OPEN },
{ "symref-create", parse_cmd_symref_create, 2, UPDATE_REFS_OPEN },
{ "symref-delete", parse_cmd_symref_delete, 2, UPDATE_REFS_OPEN },
{ "symref-verify", parse_cmd_symref_verify, 2, UPDATE_REFS_OPEN },