1 files changed, 17 insertions, 9 deletions

diff --git a/src/corelib/tools/qvector.h b/src/corelib/tools/qvector.h
index 4ff2b9f8e0..0f2acd6986 100644
--- a/src/corelib/tools/qvector.h
+++ b/src/corelib/tools/qvector.h
@@ -234,11 +234,15 @@ private:
     friend class QRegion; // Optimization for QRegion::rects()
 
     void reallocData(const int size, const int alloc, QArrayData::AllocationOptions options = QArrayData::Default);
+    void reallocData(const int sz) { reallocData(sz, d->alloc); }
     void freeData(Data *d);
     void defaultConstruct(T *from, T *to);
     void copyConstruct(const T *srcFrom, const T *srcTo, T *dstFrom);
     void destruct(T *from, T *to);
-
+    bool isValidIterator(const iterator &i) const
+    {
+        return (i <= d->end()) && (d->begin() <= i);
+    }
     class AlignmentDummy { Data header; T array[1]; };
 };
 
@@ -560,24 +564,25 @@ void QVector<T>::append(const T &t)
 }
 
 template <typename T>
-inline void QVector<T>::removeLast()
+void QVector<T>::removeLast()
 {
     Q_ASSERT(!isEmpty());
+    Q_ASSERT(d->alloc);
 
-    if (d->alloc) {
-        if (d->ref.isShared()) {
-            reallocData(d->size - 1, int(d->alloc));
-            return;
-        }
-        if (QTypeInfo<T>::isComplex)
-            (d->data() + d->size - 1)->~T();
+    if (!d->ref.isShared()) {
         --d->size;
+        if (QTypeInfo<T>::isComplex)
+            (d->data() + d->size)->~T();
+    } else {
+        reallocData(d->size - 1);
     }
 }
 
 template <typename T>
 typename QVector<T>::iterator QVector<T>::insert(iterator before, size_type n, const T &t)
 {
+    Q_ASSERT_X(isValidIterator(before),  "QVector::insert", "The specified iterator argument 'before' is invalid");
+
     int offset = std::distance(d->begin(), before);
     if (n != 0) {
         const T copy(t);
@@ -611,6 +616,9 @@ typename QVector<T>::iterator QVector<T>::insert(iterator before, size_type n, c
 template <typename T>
 typename QVector<T>::iterator QVector<T>::erase(iterator abegin, iterator aend)
 {
+    Q_ASSERT_X(isValidIterator(abegin), "QVector::erase", "The specified iterator argument 'abegin' is invalid");
+    Q_ASSERT_X(isValidIterator(aend), "QVector::erase", "The specified iterator argument 'aend' is invalid");
+
     const int itemsToErase = aend - abegin;
 
     if (!itemsToErase)