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(reason instanceof InvalidPDFException).toEqual(true);
        expect(reason.message).toEqual(
          "The PDF file is empty, i.e. its size is zero bytes."
        );
      }
      await loadingTask.destroy();
    });
    it("checks that `docId`s are unique and increasing", async function () {
      const loadingTask1 = getDocument(basicApiGetDocumentParams);
      expect(loadingTask1 instanceof PDFDocumentLoadingTask).toEqual(true);
      await loadingTask1.promise;
      const docId1 = loadingTask1.docId;
      const loadingTask2 = getDocument(basicApiGetDocumentParams);
      expect(loadingTask2 instanceof PDFDocumentLoadingTask).toEqual(true);
      await loadingTask2.promise;
      const docId2 = loadingTask2.docId;
      expect(docId1).not.toEqual(docId2);
      const docIdRegExp = /^d(\d+)$/,
        docNum1 = docIdRegExp.exec(docId1)?.[1],
        docNum2 = docIdRegExp.exec(docId2)?.[1];
      expect(+docNum1).toBeLessThan(+docNum2);
      await Promise.all([loadingTask1.destroy(), loadingTask2.destroy()]);
    });
  });
  describe("PDFWorker", function () {
    it("worker created or destroyed", async function () {
      if (isNodeJS) {
        pending("Worker is not supported in Node.js.");
      }
      const worker = new PDFWorker({ name: "test1" });