Here, i have attached the PDF, that PDF document contains "Nudi" as an embedded font. When i searching the particular word (that in Nudi font), the search result selecting the word that context next to the exact word.

Link to PDF file (or attach file here):
[sample_pdf.zip](https://github.com/mozilla/pdf.js/files/229582/sample_pdf.zip)

Configuration:
- Web browser and its version: Mozilla 45.0.2
- Operating system and its version: Windows 7
- PDF.js version: 1.4.20-disc

What is the expected behavior? (add screenshot)
![find_01](https://cloud.githubusercontent.com/assets/17423938/14704922/c2e67f2c-07d4-11e6-9320-9aed2578d377.png)

if (!(this.textContent || this.textContentStream) || this.renderingDone) {
      return;
    }
    this.cancel();
    this.textDivs = [];
    const textLayerFrag = document.createDocumentFragment();
    this.textLayerRenderTask = renderTextLayer({
      textContent: this.textContent,
      textContentStream: this.textContentStream,
      container: textLayerFrag,
      viewport: this.viewport,
      textDivs: this.textDivs,
      textContentItemsStr: this.textContentItemsStr,
      timeout,
      enhanceTextSelection: this.enhanceTextSelection,
    });
    this.textLayerRenderTask.promise.then(
      () => {
        this.textLayerDiv.appendChild(textLayerFrag);
        this._finishRendering();
        this._updateMatches();
      },
      function (reason) {
        
      }