2 files changed, 8 insertions, 1 deletions
diff --git a/src/corelib/tools/qarraydata.h b/src/corelib/tools/qarraydata.h
index ae4cbc3081..78fbc9cf32 100644
--- a/src/corelib/tools/qarraydata.h
+++ b/src/corelib/tools/qarraydata.h
@@ -91,6 +91,13 @@ struct Q_CORE_EXPORT QArrayData
 
     Q_DECLARE_FLAGS(AllocationOptions, AllocationOption)
 
+    size_t detachCapacity(size_t newSize) const
+    {
+        if (capacityReserved && newSize < alloc)
+            return alloc;
+        return newSize;
+    }
+
     AllocationOptions detachFlags() const
     {
         AllocationOptions result;
diff --git a/src/corelib/tools/qarraydatapointer.h b/src/corelib/tools/qarraydatapointer.h
index f5ad53aa54..4eb90ac35e 100644
--- a/src/corelib/tools/qarraydatapointer.h
+++ b/src/corelib/tools/qarraydatapointer.h
@@ -171,7 +171,7 @@ public:
 private:
     Data *clone(QArrayData::AllocationOptions options) const Q_REQUIRED_RESULT
     {
-        QArrayDataPointer copy(Data::allocate(d->alloc ? d->alloc : d->size,
+        QArrayDataPointer copy(Data::allocate(d->detachCapacity(d->size),
                     options));
         if (d->size)
             copy->copyAppend(d->begin(), d->end());