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):

buildGetDocumentParams("annotation-line.pdf")
      );
      const pdfDoc = await loadingTask.promise;
      const markInfo = await pdfDoc.getMarkInfo();
      expect(markInfo.Marked).toEqual(true);
      expect(markInfo.UserProperties).toEqual(false);
      expect(markInfo.Suspects).toEqual(false);
    });
    it("gets data", async function () {
      const data = await pdfDocument.getData();
      expect(data instanceof Uint8Array).toEqual(true);
      expect(data.length).toEqual(basicApiFileLength);
    });
    it("gets download info", async function () {
      const downloadInfo = await pdfDocument.getDownloadInfo();
      expect(downloadInfo).toEqual({ length: basicApiFileLength });
    });
    it("gets document stats", async function () {
      const stats = await pdfDocument.getStats();
      expect(stats).toEqual({ streamTypes: {}, fontTypes: {} });
    });
    it("cleans up document resources", async function () {
      await pdfDocument.cleanup();
      expect(true).toEqual(true);
    });
    it("checks that fingerprints are unique", async function () {
      const loadingTask1 = getDocument(
        buildGetDocumentParams("issue4436r.pdf")
      );
      const loadingTask2 = getDocument(buildGetDocumentParams("issue4575.pdf"));