Check if image width or height are zero before proceeding.

core/fxcodec/jbig2/JBig2_Image.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include <limits.h>
 
 #include "core/fxcodec/jbig2/JBig2_Image.h"
 #include "core/fxcrt/include/fx_coordinates.h"
 #include "core/fxcrt/include/fx_safe_types.h"
 
 namespace {
 
 const int kMaxImagePixels = INT_MAX - 31;
 const int kMaxImageBytes = kMaxImagePixels / 8;
 
 }  // namespace
 
 CJBig2_Image::CJBig2_Image(int32_t w, int32_t h)
     : m_pData(nullptr),
       m_nWidth(0),
       m_nHeight(0),
       m_nStride(0),
       m_bOwnsBuffer(true) {
-  if (w < 0 || h < 0 || w > kMaxImagePixels)
+  if (w <= 0 || h <= 0 || w > kMaxImagePixels)
     return;
 
   int32_t stride_pixels = (w + 31) & ~31;
   if (h > kMaxImagePixels / stride_pixels)
     return;
 
   m_nWidth = w;
   m_nHeight = h;
   m_nStride = stride_pixels / 8;
   m_pData = FX_Alloc2D(uint8_t, m_nStride, m_nHeight);
@@ skipping 1050 matching lines @@
           dp[2] = (uint8_t)(tmp >> 8);
           dp[3] = (uint8_t)tmp;
         }
         lineSrc += m_nStride;
         lineDst += pDst->m_nStride;
       }
     }
   }
   return 1;
 }