commit b64bf874a25c7578a16539b8ba8fd294c4ed9ee0
Author: SebastianDiel <sebastian.diel@web.de>
Date:   Sat Apr 22 01:22:31 2017 +0200

    Hotfixes a crash with ONE_TO_ONE use (Incident::m_predecessor), not sure
    if relation actually works now.

diff --git a/src/querybuilder.cpp b/src/querybuilder.cpp
index 35fc258..6c870fd 100644
--- a/src/querybuilder.cpp
+++ b/src/querybuilder.cpp
@@ -1055,10 +1055,11 @@ QHash<QString, QVariant> QueryBuilder::getManyToOneAttributes(
         if ((r.getType() == RelationType::MANY_TO_ONE && props.contains(i.key()))
                 || (r.getType() == RelationType::ONE_TO_ONE && r.getMappedBy().isEmpty())) {
             auto v = props.value(i.key()).read(entity.data());
-            QSharedPointer<Entity> e = EntityInstanceFactory::castQVariant(v);
-            if (e) {
-                this->insertRelationId(e.data(), map, i.key());
-            }
+            if (v.isValid()) {
+                QSharedPointer<Entity> e = EntityInstanceFactory::castQVariant(v);
+                if (e) {
+                    this->insertRelationId(e.data(), map, i.key());
+                }
         }
         ++i;
     }