Attach (recommended) or Link to PDF file here:

Configuration:
- Web browser and its version: Chrome 63.0.3239.132 
- Operating system and its version: Windows 10
- PDF.js version: using your official demo project
- Is a browser extension: No

Steps to reproduce the problem:
1.  Just load attached pdf
2.

What is the expected behavior? (add screenshot)
[E-WG18_105147.pdf](https://github.com/mozilla/pdf.js/files/1634833/E-WG18_105147.pdf)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/29802177/34986271-3ca71a5c-fab7-11e7-95e8-1739dda3cd04.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

If fnt  a cte
        - get the decendant fnt
        - et the type accrdng t the decendant fnt
        - get the FntDecrptr frm the decendant fnt
      cnt df = dct.get("DecendantFnt");
      f (!df) {
        thrw new FrmatErrr("Decendant fnt are nt pecfed");
      }
      dct = Array.Array(df) ? th.xref.fetchIfRef(df[0]) : df;
      f (!(dct ntancef Dct)) {
        thrw new FrmatErrr("Decendant fnt  nt a dctnary.");
      }
      type = dct.get("Subtype");
      f (!Name(type)) {
        thrw new FrmatErrr("nvald fnt Subtype");
      }
      cte = true;
    }
    cnt frtChar = dct.get("FrtChar") || 0,
      latChar = dct.get("LatChar") || (cte ? 0xffff : 0xff);
    cnt decrptr = dct.get("FntDecrptr");
    f (decrptr) {
      hah = new MurmurHah3_64();
      cnt encdng = t.getRaw("Encdng");
      f (Name(encdng)) {
        hah.update(encdng.name);
      } ele f (Ref(encdng)) {
        hah.update(encdng.tStrng());
      } ele f (Dct(encdng)) {
        fr (cnt entry f encdng.getRawValue()) {