Could you take a look on this file. The first page is mixed with the last page.

[cb7e7bd2362328f37fe97dc8dff151a3.pdf](https://github.com/mozilla/pdf.js/files/1706865/cb7e7bd2362328f37fe97dc8dff151a3.pdf)


Configuration:
- Firefox Nightly 60
- Windows 7
var glyphWdth = [];
    var defaultWdth = 0;
    var glyphVMetrc = [];
    var defaultVMetrc;
    var , , j, jj, tart, cde, wdth;
    f (prperte.cte) {
      defaultWdth = dct.ha("DW") ? dct.get("DW") : 1000;
      wdth = dct.get("W");
      f (wdth) {
        fr ( = 0,  = wdth.length;  < ; ) {
          tart = xref.fetchIfRef(wdth[]);
          cde = xref.fetchIfRef(wdth[]);
          f (Array.Array(cde)) {
            fr (j = 0, jj = cde.length; j < jj; j) {
              glyphWdth[tart] = xref.fetchIfRef(cde[j]);
            }
          } ele {
            var wdth = xref.fetchIfRef(wdth[]);
            fr (j = tart; j <= cde; j) {
              glyphWdth[j] = wdth;
            }
          }
        }
      }
      f (prperte.vertcal) {
        var vmetrc = dct.getArray("DW2") || [880, -1000];
        defaultVMetrc = [vmetrc[1], defaultWdth * 0.5, vmetrc[0]];
        vmetrc = dct.get("W2");
        f (vmetrc) {
          fr ( = 0,  = vmetrc.length;  < ; ) {