reftable: implement refname validation

The packed/loose format has restrictions on refnames: a and a/b cannot
coexist. This limitation does not apply to reftable per se, but must be
maintained for interoperability. This code adds validation routines to
abort transactions that are trying to add invalid names.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 102 insertions, 0 deletions

diff --git a/reftable/refname_test.c b/reftable/refname_test.c
new file mode 100644
index 0000000000..8645cd93bb
--- /dev/null
+++ b/reftable/refname_test.c
@@ -0,0 +1,102 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "basics.h"
+#include "block.h"
+#include "blocksource.h"
+#include "constants.h"
+#include "reader.h"
+#include "record.h"
+#include "refname.h"
+#include "reftable-error.h"
+#include "reftable-writer.h"
+#include "system.h"
+
+#include "test_framework.h"
+#include "reftable-tests.h"
+
+struct testcase {
+	char *add;
+	char *del;
+	int error_code;
+};
+
+static void test_conflict(void)
+{
+	struct reftable_write_options opts = { 0 };
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_writer *w =
+		reftable_new_writer(&strbuf_add_void, &buf, &opts);
+	struct reftable_ref_record rec = {
+		.refname = "a/b",
+		.value_type = REFTABLE_REF_SYMREF,
+		.value.symref = "destination", /* make sure it's not a symref.
+						*/
+		.update_index = 1,
+	};
+	int err;
+	int i;
+	struct reftable_block_source source = { NULL };
+	struct reftable_reader *rd = NULL;
+	struct reftable_table tab = { NULL };
+	struct testcase cases[] = {
+		{ "a/b/c", NULL, REFTABLE_NAME_CONFLICT },
+		{ "b", NULL, 0 },
+		{ "a", NULL, REFTABLE_NAME_CONFLICT },
+		{ "a", "a/b", 0 },
+
+		{ "p/", NULL, REFTABLE_REFNAME_ERROR },
+		{ "p//q", NULL, REFTABLE_REFNAME_ERROR },
+		{ "p/./q", NULL, REFTABLE_REFNAME_ERROR },
+		{ "p/../q", NULL, REFTABLE_REFNAME_ERROR },
+
+		{ "a/b/c", "a/b", 0 },
+		{ NULL, "a//b", 0 },
+	};
+	reftable_writer_set_limits(w, 1, 1);
+
+	err = reftable_writer_add_ref(w, &rec);
+	EXPECT_ERR(err);
+
+	err = reftable_writer_close(w);
+	EXPECT_ERR(err);
+	reftable_writer_free(w);
+
+	block_source_from_strbuf(&source, &buf);
+	err = reftable_new_reader(&rd, &source, "filename");
+	EXPECT_ERR(err);
+
+	reftable_table_from_reader(&tab, rd);
+
+	for (i = 0; i < ARRAY_SIZE(cases); i++) {
+		struct modification mod = {
+			.tab = tab,
+		};
+
+		if (cases[i].add) {
+			mod.add = &cases[i].add;
+			mod.add_len = 1;
+		}
+		if (cases[i].del) {
+			mod.del = &cases[i].del;
+			mod.del_len = 1;
+		}
+
+		err = modification_validate(&mod);
+		EXPECT(err == cases[i].error_code);
+	}
+
+	reftable_reader_free(rd);
+	strbuf_release(&buf);
+}
+
+int refname_test_main(int argc, const char *argv[])
+{
+	RUN_TEST(test_conflict);
+	return 0;
+}