remotebackend: use 0 for denoting unknown serial which is uint32_t

remotebackend.cc:610:51: runtime error: -1 is outside the range of representable values of type 'unsigned int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior remotebackend.cc:610:51 in

(cherry picked from commit 79989810021b4f08b1365bca9b1fc16c6d9aad8e)

diff --git a/modules/remotebackend/remotebackend.cc b/modules/remotebackend/remotebackend.cc
index 220b518f0e0a73a5a820ffc5b54a3121a656335d..7fb4d015f8bfc8e617eb69c2fc8b1a4c3ab6bd67 100644 (file)
--- a/modules/remotebackend/remotebackend.cc
+++ b/modules/remotebackend/remotebackend.cc
@@ -607,7 +607,7 @@ void RemoteBackend::parseDomainInfo(const Json &obj, DomainInfo &di)
    for(const auto& master: obj["masters"].array_items())
      di.masters.push_back(ComboAddress(master.string_value(), 53));
 
-   di.notified_serial = static_cast<unsigned int>(doubleFromJson(obj, "notified_serial", -1));
+   di.notified_serial = static_cast<unsigned int>(doubleFromJson(obj, "notified_serial", 0));
    di.serial = static_cast<unsigned int>(obj["serial"].number_value());
    di.last_check = static_cast<time_t>(obj["last_check"].number_value());