From: Karthik Nayak <karthik.188@xxxxxxxxx>
The 'symref-verify' command allows users to verify if a provided <ref>
contains the provided <old-target> without changing the <ref>. If
<old-target> is not provided, the command will verify that the <ref>
doesn't exist.
The command allows users to verify symbolic refs within a transaction,
and this means users can perform a set of changes in a transaction only
when the verification holds good.
Since we're checking for symbolic refs, this command will only work with
the 'no-deref' mode. This is because any dereferenced symbolic ref will
point to an object and not a ref and the regular 'verify' command can be
used in such situations.
Add required tests for symref support in 'verify'. Since we're here,
also add reflog checks for the pre-existing 'verify' tests, there is no
divergence from behavior, but we never tested to ensure that reflog
wasn't affected by the 'verify' command.
Helped-by: Patrick Steinhardt <ps@xxxxxx>
Signed-off-by: Karthik Nayak <karthik.188@xxxxxxxxx>
---
Documentation/git-update-ref.txt | 7 +++
builtin/update-ref.c | 80 +++++++++++++++++++++++----
refs.c | 11 +++-
refs.h | 1 +
t/t1400-update-ref.sh | 94 +++++++++++++++++++++++++++++++-
t/t1416-ref-transaction-hooks.sh | 30 ++++++++++
6 files changed, 208 insertions(+), 15 deletions(-)
diff --git a/Documentation/git-update-ref.txt b/Documentation/git-update-ref.txt
index 374a2ebd2b..9fe78b3501 100644
--- a/Documentation/git-update-ref.txt
+++ b/Documentation/git-update-ref.txt
@@ -65,6 +65,7 @@ performs all modifications together. Specify commands of the form:
create SP <ref> SP <new-oid> LF
delete SP <ref> [SP <old-oid>] LF
verify SP <ref> [SP <old-oid>] LF
+ symref-verify SP <ref> [SP <old-target>] LF
option SP <opt> LF
start LF
prepare LF
@@ -86,6 +87,7 @@ quoting:
create SP <ref> NUL <new-oid> NUL
delete SP <ref> NUL [<old-oid>] NUL
verify SP <ref> NUL [<old-oid>] NUL
+ symref-verify SP <ref> [NUL <old-target>] NUL
option SP <opt> NUL
start NUL
prepare NUL
@@ -117,6 +119,11 @@ verify::
Verify <ref> against <old-oid> but do not change it. If
<old-oid> is zero or missing, the ref must not exist.
+symref-verify::
+ Verify symbolic <ref> against <old-target> but do not change it.
+ If <old-target> is missing, the ref must not exist. Can only be
+ used in `no-deref` mode.
+
option::
Modify the behavior of the next command naming a <ref>.
The only valid option is `no-deref` to avoid dereferencing
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 6cda1c08aa..50f5472160 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -76,6 +76,29 @@ static char *parse_refname(const char **next)
return strbuf_detach(&ref, NULL);
}
+/*
+ * Wrapper around parse_refname which skips the next delimiter.
+ */
+static char *parse_next_refname(const char **next)
+{
+ 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)++;
+
+ return parse_refname(next);
+}
+
+
/*
* The value being parsed is <old-oid> (as opposed to <new-oid>; the
* difference affects which error messages are generated):
@@ -297,11 +320,47 @@ static void parse_cmd_verify(struct ref_transaction *transaction,
die("verify %s: extra input: %s", refname, next);
if (ref_transaction_verify(transaction, refname, &old_oid,
- update_flags, &err))
+ NULL, update_flags, &err))
+ die("%s", err.buf);
+
+ update_flags = default_flags;
+ free(refname);
+ strbuf_release(&err);
+}
+
+static void parse_cmd_symref_verify(struct ref_transaction *transaction,
+ const char *next, const char *end)
+{
+ struct strbuf err = STRBUF_INIT;
+ struct object_id old_oid;
+ char *refname, *old_target;
+
+ if (!(update_flags & REF_NO_DEREF))
+ die("symref-verify: cannot operate with deref mode");
+
+ refname = parse_refname(&next);
+ if (!refname)
+ die("symref-verify: missing <ref>");
+
+ /*
+ * old_ref is optional, if not provided, we need to ensure that the
+ * ref doesn't exist.
+ */
+ old_target = parse_next_refname(&next);
+ if (!old_target)
+ oidcpy(&old_oid, null_oid());
+
+ if (*next != line_termination)
+ die("symref-verify %s: extra input: %s", refname, next);
+
+ if (ref_transaction_verify(transaction, refname,
+ old_target ? NULL : &old_oid,
+ old_target, update_flags, &err))
die("%s", err.buf);
update_flags = default_flags;
free(refname);
+ free(old_target);
strbuf_release(&err);
}
@@ -380,15 +439,16 @@ static const struct parse_cmd {
unsigned args;
enum update_refs_state state;
} command[] = {
- { "update", parse_cmd_update, 3, UPDATE_REFS_OPEN },
- { "create", parse_cmd_create, 2, UPDATE_REFS_OPEN },
- { "delete", parse_cmd_delete, 2, UPDATE_REFS_OPEN },
- { "verify", parse_cmd_verify, 2, UPDATE_REFS_OPEN },
- { "option", parse_cmd_option, 1, UPDATE_REFS_OPEN },
- { "start", parse_cmd_start, 0, UPDATE_REFS_STARTED },
- { "prepare", parse_cmd_prepare, 0, UPDATE_REFS_PREPARED },
- { "abort", parse_cmd_abort, 0, UPDATE_REFS_CLOSED },
- { "commit", parse_cmd_commit, 0, UPDATE_REFS_CLOSED },
+ { "update", parse_cmd_update, 3, UPDATE_REFS_OPEN },
+ { "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-verify", parse_cmd_symref_verify, 2, UPDATE_REFS_OPEN },
+ { "option", parse_cmd_option, 1, UPDATE_REFS_OPEN },
+ { "start", parse_cmd_start, 0, UPDATE_REFS_STARTED },
+ { "prepare", parse_cmd_prepare, 0, UPDATE_REFS_PREPARED },
+ { "abort", parse_cmd_abort, 0, UPDATE_REFS_CLOSED },
+ { "commit", parse_cmd_commit, 0, UPDATE_REFS_CLOSED },
};
static void update_refs_stdin(void)
diff --git a/refs.c b/refs.c
index 50d8d7d777..cdc4d25557 100644
--- a/refs.c
+++ b/refs.c
@@ -1297,14 +1297,19 @@ int ref_transaction_delete(struct ref_transaction *transaction,
int ref_transaction_verify(struct ref_transaction *transaction,
const char *refname,
const struct object_id *old_oid,
+ const char *old_target,
unsigned int flags,
struct strbuf *err)
{
- if (!old_oid)
- BUG("verify called with old_oid set to NULL");
+ if (!old_target && !old_oid)
+ BUG("verify called with old_oid and old_target set to NULL");
+ if (old_oid && old_target)
+ BUG("verify called with both old_oid and old_target set");
+ if (old_target && !(flags & REF_NO_DEREF))
+ BUG("verify cannot operate on symrefs with deref mode");
return ref_transaction_update(transaction, refname,
NULL, old_oid,
- NULL, NULL,
+ NULL, old_target,
flags, NULL, err);
}
diff --git a/refs.h b/refs.h
index 34568ee1fb..906299351c 100644
--- a/refs.h
+++ b/refs.h
@@ -736,6 +736,7 @@ int ref_transaction_delete(struct ref_transaction *transaction,
int ref_transaction_verify(struct ref_transaction *transaction,
const char *refname,
const struct object_id *old_oid,
+ const char *old_target,
unsigned int flags,
struct strbuf *err);
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index bbee2783ab..52801be07d 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -892,17 +892,23 @@ test_expect_success 'stdin update/create/verify combination works' '
'
test_expect_success 'stdin verify succeeds for correct value' '
+ test-tool ref-store main for-each-reflog-ent $m >before &&
git rev-parse $m >expect &&
echo "verify $m $m" >stdin &&
git update-ref --stdin <stdin &&
git rev-parse $m >actual &&
- test_cmp expect actual
+ test_cmp expect actual &&
+ test-tool ref-store main for-each-reflog-ent $m >after &&
+ test_cmp before after
'
test_expect_success 'stdin verify succeeds for missing reference' '
+ test-tool ref-store main for-each-reflog-ent $m >before &&
echo "verify refs/heads/missing $Z" >stdin &&
git update-ref --stdin <stdin &&
- test_must_fail git rev-parse --verify -q refs/heads/missing
+ test_must_fail git rev-parse --verify -q refs/heads/missing &&
+ test-tool ref-store main for-each-reflog-ent $m >after &&
+ test_cmp before after
'
test_expect_success 'stdin verify treats no value as missing' '
@@ -1643,4 +1649,88 @@ test_expect_success PIPE 'transaction flushes status updates' '
test_cmp expected actual
'
+format_command () {
+ if test "$1" = "-z"
+ then
+ shift
+ printf "$F" "$@"
+ else
+ echo "$@"
+ fi
+}
+
+for type in "" "-z"
+do
+
+ test_expect_success "stdin $type symref-verify fails without --no-deref" '
+ git symbolic-ref refs/heads/symref $a &&
+ format_command $type "symref-verify refs/heads/symref" "$a" >stdin &&
+ test_must_fail git update-ref --stdin $type <stdin 2>err &&
+ grep "fatal: symref-verify: cannot operate with deref mode" err
+ '
+
+ test_expect_success "stdin $type symref-verify fails with too many arguments" '
+ format_command $type "symref-verify refs/heads/symref" "$a" "$a" >stdin &&
+ test_must_fail git update-ref --stdin $type --no-deref <stdin 2>err &&
+ if test "$type" = "-z"
+ then
+ grep "fatal: unknown command: $a" err
+ else
+ grep "fatal: symref-verify refs/heads/symref: extra input: $a" err
+ fi
+ '
+
+ test_expect_success "stdin $type symref-verify succeeds for correct value" '
+ git symbolic-ref refs/heads/symref >expect &&
+ test-tool ref-store main for-each-reflog-ent refs/heads/symref >before &&
+ format_command $type "symref-verify refs/heads/symref" "$a" >stdin &&
+ git update-ref --stdin $type --no-deref <stdin &&
+ git symbolic-ref refs/heads/symref >actual &&
+ test_cmp expect actual &&
+ test-tool ref-store main for-each-reflog-ent refs/heads/symref >after &&
+ test_cmp before after
+ '
+
+ test_expect_success "stdin $type symref-verify fails with no value" '
+ git symbolic-ref refs/heads/symref >expect &&
+ format_command $type "symref-verify refs/heads/symref" "" >stdin &&
+ test_must_fail git update-ref --stdin $type --no-deref <stdin
+ '
+
+ test_expect_success "stdin $type symref-verify succeeds for dangling reference" '
+ test_when_finished "git symbolic-ref -d refs/heads/symref2" &&
+ test_must_fail git symbolic-ref refs/heads/nonexistent &&
+ git symbolic-ref refs/heads/symref2 refs/heads/nonexistent &&
+ format_command $type "symref-verify refs/heads/symref2" "refs/heads/nonexistent" >stdin &&
+ git update-ref --stdin $type --no-deref <stdin
+ '
+
+ test_expect_success "stdin $type symref-verify fails for missing reference" '
+ test-tool ref-store main for-each-reflog-ent refs/heads/symref >before &&
+ format_command $type "symref-verify refs/heads/missing" "refs/heads/unknown" >stdin &&
+ test_must_fail git update-ref --stdin $type --no-deref <stdin 2>err &&
+ grep "fatal: cannot lock ref ${SQ}refs/heads/missing${SQ}: unable to resolve reference ${SQ}refs/heads/missing${SQ}" err &&
+ test_must_fail git rev-parse --verify -q refs/heads/missing &&
+ test-tool ref-store main for-each-reflog-ent refs/heads/symref >after &&
+ test_cmp before after
+ '
+
+ test_expect_success "stdin $type symref-verify fails for wrong value" '
+ git symbolic-ref refs/heads/symref >expect &&
+ format_command $type "symref-verify refs/heads/symref" "$b" >stdin &&
+ test_must_fail git update-ref --stdin $type --no-deref <stdin &&
+ git symbolic-ref refs/heads/symref >actual &&
+ test_cmp expect actual
+ '
+
+ test_expect_success "stdin $type symref-verify fails for mistaken null value" '
+ git symbolic-ref refs/heads/symref >expect &&
+ format_command $type "symref-verify refs/heads/symref" "$Z" >stdin &&
+ test_must_fail git update-ref --stdin $type --no-deref <stdin &&
+ git symbolic-ref refs/heads/symref >actual &&
+ test_cmp expect actual
+ '
+
+done
+
test_done
diff --git a/t/t1416-ref-transaction-hooks.sh b/t/t1416-ref-transaction-hooks.sh
index 067fd57290..fd58b902f4 100755
--- a/t/t1416-ref-transaction-hooks.sh
+++ b/t/t1416-ref-transaction-hooks.sh
@@ -157,4 +157,34 @@ test_expect_success 'hook captures git-symbolic-ref updates' '
test_cmp expect actual
'
+test_expect_success 'hook gets all queued symref updates' '
+ test_when_finished "rm actual" &&
+
+ git update-ref refs/heads/branch $POST_OID &&
+ git symbolic-ref refs/heads/symref refs/heads/main &&
+
+ test_hook reference-transaction <<-\EOF &&
+ echo "$*" >>actual
+ while read -r line
+ do
+ printf "%s\n" "$line"
+ done >>actual
+ EOF
+
+ cat >expect <<-EOF &&
+ prepared
+ ref:refs/heads/main $ZERO_OID refs/heads/symref
+ committed
+ ref:refs/heads/main $ZERO_OID refs/heads/symref
+ EOF
+
+ git update-ref --no-deref --stdin <<-EOF &&
+ start
+ symref-verify refs/heads/symref refs/heads/main
+ prepare
+ commit
+ EOF
+ test_cmp expect actual
+'
+
test_done
--
2.43.GIT
