xrow: fix xrow_decode_synchro rejecting non-int types

There was an error in xrow_decode_synchro: it compared the expected type
of the value to the type of the key (MP_UINT) instead of the type of the
actual value. This went unnoticed because all values in synchro requests
were integers.

This is going to change soon, when PROMOTE requests will start holding a
vclock, so fix the wrong type check.

In-scope-of tarantool#9138

NO_DOC=bugfix
NO_CHANGELOG=not user-visible

src/box/xrow.c

@@ -1294,7 +1294,8 @@ xrow_decode_synchro(const struct xrow_header *row, struct synchro_request *req)
 			continue;
 		}
 		uint8_t key = mp_decode_uint(&d);
-		if (key < iproto_key_MAX && iproto_key_type[key] != type) {
+		if (key < iproto_key_MAX &&
+		    iproto_key_type[key] != mp_typeof(*d)) {
 			xrow_on_decode_err(row, ER_INVALID_MSGPACK,
 					   "request body");
 			return -1;

test/unit/xrow.cc

@@ -543,6 +543,31 @@ test_xrow_decode_unknown_key(void)
 	footer();
 }
 
+static void
+test_xrow_decode_synchro_types(void)
+{
+	header();
+	plan(1);
+
+	char buf[128];
+
+	const char *p = buf;
+	const char *end = buf + mp_format(buf, sizeof(buf), "{%u%s}",
+					  IPROTO_INSTANCE_NAME, "somename");
+	struct xrow_header header;
+	memset(&header, 0, sizeof(header));
+	header.bodycnt = 1;
+	header.body[0].iov_base = buf;
+	header.body[0].iov_len = mp_format(buf, sizeof(buf), "{%u%s}",
+					   IPROTO_INSTANCE_NAME, "somename");
+	struct synchro_request synchro;
+	is(xrow_decode_synchro(&header, &synchro), 0,
+	   "xrow_decode_synchro correctly handles key types");
+
+	check_plan();
+	footer();
+}
+
 static void
 test_xrow_decode_error_1(void)
 {
@@ -772,7 +797,7 @@ main(void)
 	memory_init();
 	fiber_init(fiber_c_invoke);
 	header();
-	plan(12);
+	plan(13);
 
 	random_init();
 
@@ -789,6 +814,7 @@ main(void)
 	test_xrow_decode_error_4();
 	test_xrow_decode_error_gh_9098();
 	test_xrow_decode_error_gh_9136();
+	test_xrow_decode_synchro_types();
 
 	random_free();
 	fiber_free();