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):

return loadingTask.destroy();
      });
      await Promise.all(destroyPromises);
    });
    it("should correctly render PDFs in parallel", async function () {
      let baseline1, baseline2, baseline3;
      const promiseDone = renderPDF(pdf1)
        .then(function (data1) {
          baseline1 = data1;
          return renderPDF(pdf2);
        })
        .then(function (data2) {
          baseline2 = data2;
          return renderPDF(pdf3);
        })
        .then(function (data3) {
          baseline3 = data3;
          return Promise.all([
            renderPDF(pdf1),
            renderPDF(pdf2),
            renderPDF(pdf3),
          ]);
        })
        .then(function (dataUrls) {
          expect(dataUrls[0]).toEqual(baseline1);
          expect(dataUrls[1]).toEqual(baseline2);
          expect(dataUrls[2]).toEqual(baseline3);
          return true;
        });
      await promiseDone;