Enable linting of Firefox specific code in viewer.js

- This patch uncomments a large portion of the Firefox specific code in viewer.js, by using a preprocessor "trick", to enable linting. Doing this actually uncovered some issues, e.g. variables defined multiple times.

 - This patch also fixes a spelling error, `adobe pdfwritter` -> `abobe pdfwriter`, in the `KNOWN_GENERATORS` list used when reporting telemetry data in Firefox.

*Please note:* there's still some Firefox specific code that is commented out, but it's usually just one (or two) lines of code. Hence the risk that errors creep in should be much lower, compared to entire code-blocks.

web/viewer.js

@@ -595,21 +595,23 @@ var PDFViewerApplication = {
 
   fallback: function pdfViewFallback(featureId) {
 //#if !(FIREFOX || MOZCENTRAL)
-//  return;
+    /* jshint -W027 */
+    return;
 //#else
-//  // Only trigger the fallback once so we don't spam the user with messages
-//  // for one PDF.
-//  if (this.fellback)
-//    return;
-//  this.fellback = true;
-//  var url = this.url.split('#')[0];
-//  FirefoxCom.request('fallback', { featureId: featureId, url: url },
-//    function response(download) {
-//      if (!download) {
-//        return;
-//      }
-//      PDFViewerApplication.download();
-//    });
+    // Only trigger the fallback once so we don't spam the user with messages
+    // for one PDF.
+    if (this.fellback) {
+      return;
+    }
+    this.fellback = true;
+    var url = this.url.split('#')[0];
+    FirefoxCom.request('fallback', { featureId: featureId, url: url },
+      function response(download) {
+        if (!download) {
+          return;
+        }
+        PDFViewerApplication.download();
+      });
 //#endif
   },
 
@@ -1035,32 +1037,37 @@ var PDFViewerApplication = {
         self.fallback(PDFJS.UNSUPPORTED_FEATURES.forms);
       }
 
+//#if !PRODUCTION
+      /* jshint -W027 */
+      return;
+//#endif
 //#if (FIREFOX || MOZCENTRAL)
-//    var versionId = String(info.PDFFormatVersion).slice(-1) | 0;
-//    var generatorId = 0;
-//    var KNOWN_GENERATORS = ["acrobat distiller", "acrobat pdfwritter",
-//     "adobe livecycle", "adobe pdf library", "adobe photoshop", "ghostscript",
-//     "tcpdf", "cairo", "dvipdfm", "dvips", "pdftex", "pdfkit", "itext",
-//     "prince", "quarkxpress", "mac os x", "microsoft", "openoffice", "oracle",
-//     "luradocument", "pdf-xchange", "antenna house", "aspose.cells", "fpdf"];
-//    var generatorId = 0;
-//    if (info.Producer) {
-//      KNOWN_GENERATORS.some(function (generator, s, i) {
-//        if (generator.indexOf(s) < 0) {
-//          return false;
-//        }
-//        generatorId = i + 1;
-//        return true;
-//      }.bind(null, info.Producer.toLowerCase()));
-//    }
-//    var formType = !info.IsAcroFormPresent ? null : info.IsXFAPresent ?
-//                   'xfa' : 'acroform';
-//    FirefoxCom.request('reportTelemetry', JSON.stringify({
-//      type: 'documentInfo',
-//      version: versionId,
-//      generator: generatorId,
-//      formType: formType
-//    }));
+      var versionId = String(info.PDFFormatVersion).slice(-1) | 0;
+      var generatorId = 0;
+      var KNOWN_GENERATORS = [
+        'acrobat distiller', 'acrobat pdfwriter', 'adobe livecycle',
+        'adobe pdf library', 'adobe photoshop', 'ghostscript', 'tcpdf',
+        'cairo', 'dvipdfm', 'dvips', 'pdftex', 'pdfkit', 'itext', 'prince',
+        'quarkxpress', 'mac os x', 'microsoft', 'openoffice', 'oracle',
+        'luradocument', 'pdf-xchange', 'antenna house', 'aspose.cells', 'fpdf'
+      ];
+      if (info.Producer) {
+        KNOWN_GENERATORS.some(function (generator, s, i) {
+          if (generator.indexOf(s) < 0) {
+            return false;
+          }
+          generatorId = i + 1;
+          return true;
+        }.bind(null, info.Producer.toLowerCase()));
+      }
+      var formType = !info.IsAcroFormPresent ? null : info.IsXFAPresent ?
+                     'xfa' : 'acroform';
+      FirefoxCom.request('reportTelemetry', JSON.stringify({
+        type: 'documentInfo',
+        version: versionId,
+        generator: generatorId,
+        formType: formType
+      }));
 //#endif
     });
   },
@@ -1309,10 +1316,14 @@ var PDFViewerApplication = {
       this.pdfViewer.getPageView(i).beforePrint();
     }
 
+//#if !PRODUCTION
+    /* jshint -W027 */
+    return;
+//#endif
 //#if (FIREFOX || MOZCENTRAL)
-//    FirefoxCom.request('reportTelemetry', JSON.stringify({
-//      type: 'print'
-//    }));
+    FirefoxCom.request('reportTelemetry', JSON.stringify({
+      type: 'print'
+    }));
 //#endif
   },
 
@@ -1398,7 +1409,7 @@ function webViewerInitialized() {
 //var file = DEFAULT_URL;
 //#endif
 
-//#if !(FIREFOX || MOZCENTRAL || CHROME || B2G)
+//#if GENERIC
   var fileInput = document.createElement('input');
   fileInput.id = 'fileInput';
   fileInput.className = 'fileInput';
@@ -1498,11 +1509,11 @@ function webViewerInitialized() {
   mozL10n.setLanguage(locale);
 //#endif
 //#if (FIREFOX || MOZCENTRAL)
-//if (!PDFViewerApplication.supportsDocumentFonts) {
-//  PDFJS.disableFontFace = true;
-//  console.warn(mozL10n.get('web_fonts_disabled', null,
-//    'Web fonts are disabled: unable to use embedded PDF fonts.'));
-//}
+  if (!PDFViewerApplication.supportsDocumentFonts) {
+    PDFJS.disableFontFace = true;
+    console.warn(mozL10n.get('web_fonts_disabled', null,
+      'Web fonts are disabled: unable to use embedded PDF fonts.'));
+  }
 //#endif
 
   if (!PDFViewerApplication.supportsPrinting) {
@@ -1676,41 +1687,49 @@ document.addEventListener('pagerendered', function (e) {
       'An error occurred while rendering the page.'), pageView.error);
   }
 
-//#if (FIREFOX || MOZCENTRAL)
-//FirefoxCom.request('reportTelemetry', JSON.stringify({
-//  type: 'pageInfo'
-//}));
-//// It is a good time to report stream and font types
-//PDFViewerApplication.pdfDocument.getStats().then(function (stats) {
-//  FirefoxCom.request('reportTelemetry', JSON.stringify({
-//    type: 'documentStats',
-//    stats: stats
-//  }));
-//});
-//#endif
-
   // If the page is still visible when it has finished rendering,
   // ensure that the page number input loading indicator is hidden.
   if (pageNumber === PDFViewerApplication.page) {
     var pageNumberInput = document.getElementById('pageNumber');
     pageNumberInput.classList.remove(PAGE_NUMBER_LOADING_INDICATOR);
   }
+
+//#if !PRODUCTION
+  /* jshint -W027 */
+  return;
+//#endif
+//#if (FIREFOX || MOZCENTRAL)
+  FirefoxCom.request('reportTelemetry', JSON.stringify({
+    type: 'pageInfo'
+  }));
+  // It is a good time to report stream and font types.
+  PDFViewerApplication.pdfDocument.getStats().then(function (stats) {
+    FirefoxCom.request('reportTelemetry', JSON.stringify({
+      type: 'documentStats',
+      stats: stats
+    }));
+  });
+//#endif
 }, true);
 
 document.addEventListener('textlayerrendered', function (e) {
   var pageIndex = e.detail.pageNumber - 1;
   var pageView = PDFViewerApplication.pdfViewer.getPageView(pageIndex);
 
+//#if !PRODUCTION
+  /* jshint -W027 */
+  return;
+//#endif
 //#if (FIREFOX || MOZCENTRAL)
-//if (pageView.textLayer && pageView.textLayer.textDivs &&
-//    pageView.textLayer.textDivs.length > 0 &&
-//    !PDFViewerApplication.supportsDocumentColors) {
-//  console.error(mozL10n.get('document_colors_disabled', null,
-//    'PDF documents are not allowed to use their own colors: ' +
-//    '\'Allow pages to choose their own colors\' ' +
-//    'is deactivated in the browser.'));
-//  PDFViewerApplication.fallback();
-//}
+  if (pageView.textLayer && pageView.textLayer.textDivs &&
+      pageView.textLayer.textDivs.length > 0 &&
+      !PDFViewerApplication.supportsDocumentColors) {
+    console.error(mozL10n.get('document_colors_disabled', null,
+      'PDF documents are not allowed to use their own colors: ' +
+      '\'Allow pages to choose their own colors\' ' +
+      'is deactivated in the browser.'));
+    PDFViewerApplication.fallback();
+  }
 //#endif
 }, true);