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):

it("gets fingerprints", function () {
      expect(pdfDocument.fingerprints).toEqual([
        "ea8b35919d6279a369e835bde778611b",
        null,
      ]);
    });
    it("gets fingerprints, from modified document", async function () {
      const loadingTask = getDocument(
        buildGetDocumentParams("annotation-tx.pdf")
      );
      const pdfDoc = await loadingTask.promise;
      expect(pdfDoc.fingerprints).toEqual([
        "3ebd77c320274649a68f10dbf3b9f882",
        "e7087346aa4b4ae0911c1f1643b57345",
      ]);
      await loadingTask.destroy();
    });
    it("gets page", async function () {
      const data = await pdfDocument.getPage(1);
      expect(data instanceof PDFPageProxy).toEqual(true);
      expect(data.pageNumber).toEqual(1);
    });
    it("gets non-existent page", async function () {
      let outOfRangePromise = pdfDocument.getPage(100);
      let nonIntegerPromise = pdfDocument.getPage(2.5);
      let nonNumberPromise = pdfDocument.getPage("1");
      outOfRangePromise = outOfRangePromise.then(
        function () {
          throw new Error("shall fail for out-of-range pageNumber parameter");
        },