Merge pull request #4169 from alalek:issue_4457

modules/core/include/opencv2/core/mat.inl.hpp

@@ -397,6 +397,8 @@ Mat::Mat(int _rows, int _cols, int _type, void* _data, size_t _step)
       data((uchar*)_data), datastart((uchar*)_data), dataend(0), datalimit(0),
       allocator(0), u(0), size(&rows)
 {
+    CV_Assert(total() == 0 || data != NULL);
+
     size_t esz = CV_ELEM_SIZE(_type), esz1 = CV_ELEM_SIZE1(_type);
     size_t minstep = cols * esz;
     if( _step == AUTO_STEP )
@@ -428,6 +430,8 @@ Mat::Mat(Size _sz, int _type, void* _data, size_t _step)
       data((uchar*)_data), datastart((uchar*)_data), dataend(0), datalimit(0),
       allocator(0), u(0), size(&rows)
 {
+    CV_Assert(total() == 0 || data != NULL);
+
     size_t esz = CV_ELEM_SIZE(_type), esz1 = CV_ELEM_SIZE1(_type);
     size_t minstep = cols*esz;
     if( _step == AUTO_STEP )

modules/core/src/matop.cpp

@@ -1583,12 +1583,12 @@ void MatOp_Initializer::multiply(const MatExpr& e, double s, MatExpr& res) const
 
 inline void MatOp_Initializer::makeExpr(MatExpr& res, int method, Size sz, int type, double alpha)
 {
-    res = MatExpr(getGlobalMatOpInitializer(), method, Mat(sz, type, (void*)0), Mat(), Mat(), alpha, 0);
+    res = MatExpr(getGlobalMatOpInitializer(), method, Mat(sz, type, (void*)0xEEEEEEEE), Mat(), Mat(), alpha, 0);
 }
 
 inline void MatOp_Initializer::makeExpr(MatExpr& res, int method, int ndims, const int* sizes, int type, double alpha)
 {
-    res = MatExpr(getGlobalMatOpInitializer(), method, Mat(ndims, sizes, type, (void*)0), Mat(), Mat(), alpha, 0);
+    res = MatExpr(getGlobalMatOpInitializer(), method, Mat(ndims, sizes, type, (void*)0xEEEEEEEE), Mat(), Mat(), alpha, 0);
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////////////

modules/core/test/test_mat.cpp

@@ -1178,6 +1178,11 @@ TEST(Core_IOArray, submat_create)
     EXPECT_THROW( OutputArray_create2(A.row(0)), cv::Exception );
 }
 
+TEST(Core_Mat, issue4457_pass_null_ptr)
+{
+    ASSERT_ANY_THROW(cv::Mat mask(45, 45, CV_32F, 0));
+}
+
 TEST(Core_Mat, reshape_1942)
 {
     cv::Mat A = (cv::Mat_<float>(2,3) << 3.4884074, 1.4159607, 0.78737736,  2.3456569, -0.88010466, 0.3009364);