1 files changed, 18 insertions, 11 deletions
diff --git a/src/corelib/tools/qvector.h b/src/corelib/tools/qvector.h
index d61c26dc2e..85393a3598 100644
--- a/src/corelib/tools/qvector.h
+++ b/src/corelib/tools/qvector.h
@@ -523,7 +523,7 @@ QVector<T>::QVector(int asize, const T &t)
         d = Data::allocate(asize);
         Q_CHECK_PTR(d);
         d->size = asize;
-        T* i = d->end();
+        auto i = d->end();
         while (i != d->begin())
             new (--i) T(t);
     } else {
@@ -835,18 +835,25 @@ typename QVector<T>::iterator QVector<T>::insert(iterator before, size_type n, c
         if (!isDetached() || d->size + n > int(d->alloc))
             realloc(d->size + n, QArrayData::Grow);
         if (!QTypeInfoQuery<T>::isRelocatable) {
-            T *b = d->end();
-            T *i = d->end() + n;
-            while (i != b)
-                new (--i) T;
-            i = d->end();
+            T *const e = d->end();
+            T *const b = d->begin() + offset;
+
+            T *i = e;
             T *j = i + n;
-            b = d->begin() + offset;
-            while (i != b)
-                *--j = *--i;
-            i = b+n;
+
+            // move old elements into the uninitialized space
+            while (i != b && j > e)
+                new (--j) T(std::move(*--i));
+            // move the rest of old elements into the tail using assignment
             while (i != b)
-                *--i = copy;
+                *--j = std::move(*--i);
+
+            // construct copies of t inside the uninitialized space
+            while (j != b && j > e)
+                new (--j) T(copy);
+            // use assignment to fill the recently-moved-from space
+            while (j != b)
+                *--j = copy;
         } else {
             T *b = d->begin() + offset;
             T *i = b + n;