message: imgcodecs: add null pointer check
diff: @@ -396,6 +396,8 @@ static void ApplyExifOrientation(const Mat& buf, Mat& img)
  static void*
  imread_( const String& filename, int flags, int hdrtype, Mat* mat=0 )
  {
  + CV_Assert(mat || hdrtype != LOAD_MAT); // mat is required in LOAD_MAT case
  +
  IplImage* image = 0;
  CvMat *matrix = 0;
  Mat temp, *data = &temp;
  