skip cached objects and has consistent font ids

src/api.js

@@ -489,6 +489,8 @@ var WorkerTransport = (function WorkerTransportClosure() {
       messageHandler.on('obj', function transportObj(data) {
         var id = data[0];
         var type = data[1];
+        if (this.objs.hasData(id))
+          return;
 
         switch (type) {
           case 'JpegStream':

src/evaluator.js

@@ -153,13 +153,14 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
 
         font = xref.fetchIfRef(font) || fontRes.get(fontName);
         assertWellFormed(isDict(font));
+        ++self.objIdCounter;
         if (!font.translated) {
           font.translated = self.translateFont(font, xref, resources,
                                                dependency);
           if (font.translated) {
             // keep track of each font we translated so the caller can
             // load them asynchronously before calling display on a page
-            loadedName = 'font_' + uniquePrefix + (++self.objIdCounter);
+            loadedName = 'font_' + uniquePrefix + self.objIdCounter;
             font.translated.properties.loadedName = loadedName;
             font.loadedName = loadedName;
 

test/driver.js

@@ -194,13 +194,15 @@ function nextPage(task, loadError) {
           textLayer: textLayerBuilder,
           viewport: viewport
         };
-        page.render(renderContext).then(function() {
+        var completeRender = (function(error) {
           page.destroy();
-          snapshotCurrentPage(task, false);
+          snapshotCurrentPage(task, error);
+        });
+        page.render(renderContext).then(function() {
+          completeRender(false);
         },
         function(error) {
-          page.destroy();
-          snapshotCurrentPage(task, 'render : ' + error);
+          completeRender('render : ' + error);
         });
       },
       function(error) {