ibus: SetCursorLocationRelative is not a caret

A GTK client on the Wayland backend sends this where an X11 one sends
SetCursorLocation, and ictab did not list it, so libdbus answered
UnknownMethod.  Accept it and throw it away: the absolute translation
sits inside GDK_IS_X11_DISPLAY, so the coordinates are surface local,
and ibus's own daemon will not hand them to an engine either.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

ibus.c

@@ -889,7 +889,10 @@ handlecursor(DBusConnection *c, DBusMessage *m, Ictx *ctx)
 	return reply(c, m, DBUS_TYPE_INVALID, nil);
 }
 
-/* SetEngine: there is one engine, so any name is fine. */
+/*
+ * Accepted and thrown away: there is one engine, so any name is fine,
+ * and a relative cursor location is surface local, not a caret.
+ */
 static DBusHandlerResult
 handleok(DBusConnection *c, DBusMessage *m, Ictx*)
 {
@@ -908,6 +911,7 @@ static struct {
 	{"Reset", "", handlereset},
 	{"Destroy", "", handledestroy},
 	{"SetCursorLocation", "iiii", handlecursor},
+	{"SetCursorLocationRelative", "iiii", handleok},
 	{"SetCapabilities", "u", handlecap},
 	{"SetEngine", "s", handleok},
 };

tests/ibus_live_test.c

@@ -128,6 +128,7 @@ runcontract(char *address)
 		"SetEngine",
 		"SetCapabilities",
 		"SetCursorLocation",
+		"SetCursorLocationRelative",
 	};
 	DBusConnection *conn;
 	char path[96];