The problem is: normal http:// processing is file, but file:///tmp/1.html gives extra blank line

these look related, but real empty line is generated at other places

  6216          if (!internal)
  6217              {
  6218                  fprintf(stderr, "\n%s: %s:%04d: %d\n",__func__, __FILE__,__LINE__, nlines);
  6219                  addnewline(buf, outc, outp, NULL, pos, -1, nlines); // this line is important
  6220              }
  6221          if (internal == HTML_N_INTERNAL)
  6222              internal = 0;
  6223          if (str != endp) {
  6224              line = Strsubstr(line, str - line->ptr, endp - str);
  6225              goto proc_again;
  6226          }

__func__ is displayed as:
HTMLlineproc2body The problematic origninal source has following style:

/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
	{margin:0mm;
	text-align:justify;
	text-justify:inter-ideograph;
	font-size:10.5pt;
	font-family:"游ゴシック",sans-serif;}

and it is enclosed <p> </p>

<p class="MsoNormal">the line </p>