static SegmentInfo AffineEdge(const Image *image,const AffineMatrix *affine,
  const double y,const SegmentInfo *edge)
{
  double
    intercept,
    z;

  register double
    x;

  SegmentInfo
    inverse_edge;

  /*
    Determine left and right edges.
  */
  inverse_edge.x1=edge->x1;
  inverse_edge.y1=edge->y1;
  inverse_edge.x2=edge->x2;
  inverse_edge.y2=edge->y2;
  z=affine->ry*y+affine->tx;
  if (affine->sx >= MagickEpsilon)
    {
      intercept=(-z/affine->sx);
      x=intercept;
      if (x > inverse_edge.x1)
        inverse_edge.x1=x;
      intercept=(-z+(double) image->columns)/affine->sx;
      x=intercept;
      if (x < inverse_edge.x2)
        inverse_edge.x2=x;
    }
  else
    if (affine->sx < -MagickEpsilon)
      {
        intercept=(-z+(double) image->columns)/affine->sx;
        x=intercept;
        if (x > inverse_edge.x1)
          inverse_edge.x1=x;
        intercept=(-z/affine->sx);
        x=intercept;
        if (x < inverse_edge.x2)
          inverse_edge.x2=x;
      }
    else
      if ((z < 0.0) || ((size_t) floor(z+0.5) >= image->columns))
        {
          inverse_edge.x2=edge->x1;
          return(inverse_edge);
        }
  /*
    Determine top and bottom edges.
  */
  z=affine->sy*y+affine->ty;
  if (affine->rx >= MagickEpsilon)
    {
      intercept=(-z/affine->rx);
      x=intercept;
      if (x > inverse_edge.x1)
        inverse_edge.x1=x;
      intercept=(-z+(double) image->rows)/affine->rx;
      x=intercept;
      if (x < inverse_edge.x2)
        inverse_edge.x2=x;
    }
  else
    if (affine->rx < -MagickEpsilon)
      {
        intercept=(-z+(double) image->rows)/affine->rx;
        x=intercept;
        if (x > inverse_edge.x1)
          inverse_edge.x1=x;
        intercept=(-z/affine->rx);
        x=intercept;
        if (x < inverse_edge.x2)
          inverse_edge.x2=x;
      }
    else
      if ((z < 0.0) || ((size_t) floor(z+0.5) >= image->rows))
        {
          inverse_edge.x2=edge->x2;
          return(inverse_edge);
        }
  return(inverse_edge);
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.