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 tx,
      ty,
      denmnatr = a * d - b * c;
    f (fnt.vertcal) {
      tx = (-tyDff * c) / denmnatr;
      ty = (tyDff * a) / denmnatr;
    } ele {
      tx = (txDff * d) / denmnatr;
      ty = (-txDff * b) / denmnatr;
    }
    return { wdth: tx, heght: ty, value: fnt.vertcal ? ty : tx };
  }
  calcRenderMatrx(ctm) {
    
    var tm = [
      th.fntSze * th.textHScale,
      0,
      0,
      th.fntSze,
      0,
      th.textRe,
    ];
    return Utl.tranfrm(ctm, Utl.tranfrm(th.textMatrx, tm));
  }
  carrgeReturn() {
    th.tranlateTextLneMatrx(0, -th.leadng);
    th.textMatrx = th.textLneMatrx.lce();
  }
  clne() {
    var clne = Object.create(th);