pdfviewer: debug code for crash

experimental/PdfViewer/SkPdfRenderer.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCanvas.h"
 #include "SkDevice.h"
 #include "SkForceLinking.h"
@@ skipping 247 matching lines @@
         blueBorder.setTextSize(SkDoubleToScalar(20));
 
         SkString str;
 
         const SkClipStack* clipStack = gDumpCanvas->getClipStack();
         if (clipStack) {
             SkClipStack::Iter iter(*clipStack, SkClipStack::Iter::kBottom_IterStart);
             const SkClipStack::Element* elem;
             double y = 0;
             int total = 0;
-            while (elem = iter.next()) {
+            while ((elem = iter.next()) != NULL) {
                 total++;
                 y += 30;
 
                 switch (elem->getType()) {
                     case SkClipStack::Element::kRect_Type:
                         canvas.drawRect(elem->getRect(), blueBorder);
                         canvas.drawText("Rect Clip", strlen("Rect Clip"), SkDoubleToScalar(10), SkDoubleToScalar(y), blueBorder);
                         break;
                     case SkClipStack::Element::kPath_Type:
                         canvas.drawPath(elem->getPath(), blueBorder);
@@ skipping 2347 matching lines @@
 
     rect = SkRect::MakeWH(width, height);
 
     setup_bitmap(output, (int)SkScalarToDouble(width), (int)SkScalarToDouble(height));
 
     SkAutoTUnref<SkDevice> device(SkNEW_ARGS(SkDevice, (*output)));
     SkCanvas canvas(device);
 
     return renderer.renderPage(page, &canvas, rect);
 }