1 files changed, 4 insertions, 3 deletions
diff --git a/src/qml/jsruntime/qv4memberdata.cpp b/src/qml/jsruntime/qv4memberdata.cpp
index d5f75415cc..db45c77472 100644
--- a/src/qml/jsruntime/qv4memberdata.cpp
+++ b/src/qml/jsruntime/qv4memberdata.cpp
@@ -55,13 +55,14 @@ void MemberData::markObjects(Heap::Base *that, ExecutionEngine *e)
 Heap::MemberData *MemberData::allocate(ExecutionEngine *e, uint n, Heap::MemberData *old)
 {
     Q_ASSERT(!old || old->size < n);
+    Q_ASSERT(n);
 
-    uint alloc = sizeof(Heap::MemberData) + (n)*sizeof(Value);
+    size_t alloc = MemoryManager::align(sizeof(Heap::MemberData) + (n - 1)*sizeof(Value));
     Heap::MemberData *m = e->memoryManager->allocManaged<MemberData>(alloc);
     if (old)
-        memcpy(m, old, sizeof(Heap::MemberData) + old->size * sizeof(Value));
+        memcpy(m, old, sizeof(Heap::MemberData) + (old->size - 1)* sizeof(Value));
     else
         m->init();
-    m->size = n;
+    m->size = static_cast<uint>((alloc - sizeof(Heap::MemberData) + sizeof(Value))/sizeof(Value));
     return m;
 }