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 baeFnt = dct.get("BaeFnt");
     Sme bad PDF have a trng a the fnt name.
    f (Strng(fntName)) {
      fntName = Name.get(fntName);
    }
    f (Strng(baeFnt)) {
      baeFnt = Name.get(baeFnt);
    }
    f (type !== "Type3") {
      meStr = fntName && fntName.name;
      var baeFntStr = baeFnt && baeFnt.name;
      f (fntNameStr !== baeFntStr) {
        nf(
          `The FntDecrptr' FntName  "${fntNameStr}" but ` 
            `huld be the ame a the Fnt' BaeFnt "${baeFntStr}".`
        );
         Wrkarund fr cae where e.g. fntNameStr = 'Arl' and
         baeFntStr = 'Arl,Bld' (needed when n fnt fle  embedded).
        f (fntNameStr && baeFntStr && baeFntStr.tartWth(fntNameStr)) {
          fntName = baeFnt;
        }
      }
    }
    fntName = fntName || baeFnt;
    f (!Name(fntName)) {
      thrw new FrmatErrr("nvald fnt name");
    }
    var fntFle = decrptr.get("FntFle", "FntFle2", "FntFle3");
    f (fntFle) {
      f (fntFle.dct) {