文本编码检测算法代码的一个BUG

网上流行的文本编码自动检测，一般都是拷贝过来的，一个名为erik peterson的人写的。

看了一下其代码，似乎有个地方写错了。

看代码中添加的中文注解：

sjis_probability(unsigned char* rawtext) {
  unsigned int i, rawtextlen = 0;
  
  int dbchars = 1, jpchars = 1;
  long jpfreq = 0, totalfreq = 1;
  float rangeval = 0, freqval = 0;
  int row, column, adjust;
  
  // Stage 1:  Check to see if characters fit into acceptable ranges
  rawtextlen = strlen((char*)rawtext);
  for (i = 0; i < rawtextlen-1; i++) {
    //System.err.println(rawtext[i]);
    if (rawtext[i] <= 0x7E) {
      //asciichars++;
    } else {
      dbchars++;
      if (i+1 < rawtextlen &&
	  ((0x81 <= rawtext[i] && rawtext[i] <= 0x9F) ||
	   (0xE0 <= rawtext[i] && rawtext[i] <= 0xEF)) &&
	  ((0x40 <= rawtext[i+1] && rawtext[i+1] <= 0x7E) ||
	   (0x80 <= rawtext[i+1] && rawtext[i+1] <= 0xFC)))
	{
	  jpchars++;
	  totalfreq += maxfreq;
	  row = rawtext[i];
	  column = rawtext[i+1];
	  if (column < 0x9f) {
	    adjust = 1;
	    if (column > 0x7f) {
	      column -= 0x20;
	    } else {
	      column -= 0x19;
	    }
	  } else {
	    adjust = 0; 
	    column -= 0x7e;
	  }
	  if (row < 0xa0) {
	    row = ((row - 0x70) << 1) - adjust;
	  } else {
	    row = ((row - 0xb0) << 1) - adjust;
	  }
	  
	  row -= 0x20;
	  column = 0x20; // 这里应该改为：column -= 0x20