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):

expect(info.PDFFormatVersion).toEqual("1.7");
      expect(info.IsLinearized).toEqual(false);
      expect(info.IsAcroFormPresent).toEqual(false);
      expect(info.IsXFAPresent).toEqual(false);
      expect(info.IsCollectionPresent).toEqual(false);
      expect(info.IsSignaturesPresent).toEqual(false);
      expect(metadata instanceof Metadata).toEqual(true);
      expect(metadata.get("dc:title")).toEqual("Basic API Test");
      expect(contentDispositionFilename).toEqual(null);
      expect(contentLength).toEqual(basicApiFileLength);
    });
    it("gets metadata, with custom info dict entries", async function () {
      const loadingTask = getDocument(
        buildGetDocumentParams("tracemonkey.pdf")
      );
      const pdfDoc = await loadingTask.promise;
      const { info, metadata, contentDispositionFilename, contentLength } =
        await pdfDoc.getMetadata();
      expect(info.Creator).toEqual("TeX");
      expect(info.Producer).toEqual("pdfeTeX-1.21a");
      expect(info.CreationDate).toEqual("D:20090401163925-07'00'");
      
      const custom = info.Custom;
      expect(typeof custom === "object" && custom !== null).toEqual(true);
      expect(custom["PTEX.Fullbanner"]).toEqual(
        "This is pdfeTeX, " +
          "Version 3.141592-1.21a-2.2 (Web2C 7.5.4) kpathsea version 3.5.6"
      );