1 files changed, 10 insertions, 0 deletions
diff --git a/src/corelib/tools/qvarlengtharray.h b/src/corelib/tools/qvarlengtharray.h
index 825e05ae1b..d9b85c4173 100644
--- a/src/corelib/tools/qvarlengtharray.h
+++ b/src/corelib/tools/qvarlengtharray.h
@@ -192,6 +192,11 @@ private:
         qint64 q_for_alignment_1;
         double q_for_alignment_2;
     };
+
+    bool isValidIterator(const const_iterator &i) const
+    {
+        return (i <= constEnd()) && (constBegin() <= i);
+    }
 };
 
 template <class T, int Prealloc>
@@ -355,6 +360,8 @@ inline void QVarLengthArray<T, Prealloc>::replace(int i, const T &t)
 template <class T, int Prealloc>
 Q_OUTOFLINE_TEMPLATE typename QVarLengthArray<T, Prealloc>::iterator QVarLengthArray<T, Prealloc>::insert(const_iterator before, size_type n, const T &t)
 {
+    Q_ASSERT_X(isValidIterator(before), "QVarLengthArray::insert", "The specified const_iterator argument 'before' is invalid");
+
     int offset = int(before - ptr);
     if (n != 0) {
         resize(s + n);
@@ -382,6 +389,9 @@ Q_OUTOFLINE_TEMPLATE typename QVarLengthArray<T, Prealloc>::iterator QVarLengthA
 template <class T, int Prealloc>
 Q_OUTOFLINE_TEMPLATE typename QVarLengthArray<T, Prealloc>::iterator QVarLengthArray<T, Prealloc>::erase(const_iterator abegin, const_iterator aend)
 {
+    Q_ASSERT_X(isValidIterator(abegin), "QVarLengthArray::insert", "The specified const_iterator argument 'abegin' is invalid");
+    Q_ASSERT_X(isValidIterator(aend), "QVarLengthArray::insert", "The specified const_iterator argument 'aend' is invalid");
+
     int f = int(abegin - ptr);
     int l = int(aend - ptr);
     int n = l - f;