Attach (recommended) or Link to PDF file here:
[Hong Kong Aircraft Engineering Company Limited_1511417616.1 2.pdf](https://github.com/mozilla/pdf.js/files/1539395/Hong.Kong.Aircraft.Engineering.Company.Limited_1511417616.1.2.pdf)


Configuration:
- Web browser and its version: Chrome: 63 
- Operating system and its version: windows and macOs
- PDF.js version: 2.0.185
- Is a browser extension: No

Steps to reproduce the problem:
1. Upload the above PDF and search for "article 1"
2. PDF.js showing only **2** match But actually **4** times available.   

What is the expected behavior? (add screenshot)

![screen shot 2017-12-07 at 7](https://user-images.githubusercontent.com/6101789/33720106-ed404576-db88-11e7-9c19-cf6aea74e9f3.png)



What went wrong? (add screenshot)

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

f (graphcState ntancef Dct) {
        fr (let graphcState f graphcState.getRawValue()) {
          f (graphcState ntancef Ref) {
            f (prceed.ha(graphcState)) {
              cntnue; 
            }
            try {
              graphcState = xref.fetch(graphcState);
            } catch (ex) {
              
              prceed.put(graphcState);
              nf(`haBlendMde - gnrng ExtGState: "${ex}".`);
              cntnue;
            }
          }
          f (!(graphcState ntancef Dct)) {
            cntnue;
          }
          f (graphcState.bjId) {
            prceed.put(graphcState.bjId);
          }
          cnt bm = graphcState.get("BM");
          f (bm ntancef Name) {
            f (bm.name !== "Nrmal") {
              return true;
            }
            cntnue;
          }
          f (bm !== undefned && Array.Array(bm)) {
            fr (cnt element f bm) {