Internals: throw an exception when page height or width is 0.

third_party/WebKit/Source/core/page/PrintContext.cpp

 /*
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2007 Apple Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 132 matching lines @@
         IntRect pageRect(pageLogicalLeft, pageLogicalTop, pageLogicalWidth, pageLogicalHeight);
         if (!isHorizontal)
             pageRect = pageRect.transposedRect();
         m_pageRects.append(pageRect);
 
     }
 }
 
 void PrintContext::begin(float width, float height)
 {
+    ASSERT(width > 0);
+    ASSERT(height > 0);
+
     // This function can be called multiple times to adjust printing parameters without going back to screen mode.
     m_isPrinting = true;
 
     FloatSize originalPageSize = FloatSize(width, height);
     FloatSize minLayoutSize = m_frame->resizePageRectsKeepingRatio(originalPageSize, FloatSize(width * printingMinimumShrinkFactor, height * printingMinimumShrinkFactor));
 
     // This changes layout, so callers need to make sure that they don't paint to screen while in printing mode.
     m_frame->setPrinting(true, minLayoutSize, originalPageSize, printingMaximumShrinkFactor / printingMinimumShrinkFactor);
 }
 
@@ skipping 148 matching lines @@
 
 DEFINE_TRACE(PrintContext)
 {
 #if ENABLE(OILPAN)
     visitor->trace(m_frame);
     visitor->trace(m_linkedDestinations);
 #endif
 }
 
 }