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)

matchIdx: -1,
    };
    
    this._offset = {
      pageIdx: null,
      matchIdx: null,
      wrapped: false,
    };
    this._extractTextPromises = [];
    this._pageContents = []; 
    this._matchesCountTotal = 0;
    this._pagesToSearch = null;
    this._pendingFindMatches = Object.create(null);
    this._resumePageIdx = null;
    this._dirtyMatch = false;
    clearTimeout(this._findTimeout);
    this._findTimeout = null;
    this._firstPageCapability = createPromiseCapability();
  }
  /**
   * @type {string} The (current) normalized search query.
   */
  get _query() {
    if (this._state.query !== this._rawQuery) {
      this._rawQuery = this._state.query;
      this._normalizedQuery = normalize(this._state.query);
    }
    return this._normalizedQuery;
  }
  _shouldDirtyMatch(cmd, state) {