core(test): regression test for 9507

modules/core/test/test_mat.cpp

@@ -1399,13 +1399,22 @@ TEST(Core_Matx, fromMat_)
 }
 
 #ifdef CV_CXX11
+
 TEST(Core_Matx, from_initializer_list)
 {
     Mat_<double> a = (Mat_<double>(2,2) << 10, 11, 12, 13);
     Matx22d b = {10, 11, 12, 13};
     ASSERT_EQ( cvtest::norm(a, b, NORM_INF), 0.);
 }
-#endif
+
+TEST(Core_Mat, regression_9507)
+{
+    cv::Mat m = Mat::zeros(5, 5, CV_8UC3);
+    cv::Mat m2{m};
+    EXPECT_EQ(25u, m2.total());
+}
+
+#endif // CXX11
 
 TEST(Core_InputArray, empty)
 {