JBIG2Bitmap::JBIG2Bitmap(Guint segNumA, int wA, int hA):
  JBIG2Segment(segNumA)
{
  w = wA;
  h = hA;
  line = (wA + 7) >> 3;

  if (w <= 0 || h <= 0 || line <= 0 || h >= (INT_MAX - 1) / line) {
    error(-1, "invalid width/height");
    data = NULL;
     return;
   }
  data = (Guchar *)gmallocn(h, line + 1);
   data[h * line] = 0;
 }

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.