Fix a NULL pointer crash in the CJBig2_Image copy constructor.

Also change the copy ctor to take a const ref.

BUG=560520
R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1472113002 .

3 files changed, 8 insertions, 7 deletions

diff --git a/core/src/fxcodec/jbig2/JBig2_Image.cpp b/core/src/fxcodec/jbig2/JBig2_Image.cpp
index a2a0acfe95..074458744d 100644
--- a/core/src/fxcodec/jbig2/JBig2_Image.cpp
+++ b/core/src/fxcodec/jbig2/JBig2_Image.cpp
@@ -36,7 +36,7 @@ CJBig2_Image::CJBig2_Image(int32_t w,
   m_pData = pBuf;
   m_bNeedFree = FALSE;
 }
-CJBig2_Image::CJBig2_Image(CJBig2_Image& im) {
+CJBig2_Image::CJBig2_Image(const CJBig2_Image& im) {
   m_nWidth = im.m_nWidth;
   m_nHeight = im.m_nHeight;
   m_nStride = im.m_nStride;
diff --git a/core/src/fxcodec/jbig2/JBig2_Image.h b/core/src/fxcodec/jbig2/JBig2_Image.h
index e77da9059c..c47d275cf7 100644
--- a/core/src/fxcodec/jbig2/JBig2_Image.h
+++ b/core/src/fxcodec/jbig2/JBig2_Image.h
@@ -4,8 +4,8 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
-#ifndef _JBIG2_IMAGE_H_
-#define _JBIG2_IMAGE_H_
+#ifndef CORE_SRC_FXCODEC_JBIG2_JBIG2_IMAGE_H_
+#define CORE_SRC_FXCODEC_JBIG2_JBIG2_IMAGE_H_
 
 #include "JBig2_Define.h"
 
@@ -24,7 +24,7 @@ class CJBig2_Image {
 
   CJBig2_Image(int32_t w, int32_t h, int32_t stride, uint8_t* pBuf);
 
-  CJBig2_Image(CJBig2_Image& im);
+  CJBig2_Image(const CJBig2_Image& im);
 
   ~CJBig2_Image();
 
@@ -81,4 +81,5 @@ class CJBig2_Image {
 
   FX_BOOL m_bNeedFree;
 };
-#endif
+
+#endif  // CORE_SRC_FXCODEC_JBIG2_JBIG2_IMAGE_H_
diff --git a/core/src/fxcodec/jbig2/JBig2_SddProc.cpp b/core/src/fxcodec/jbig2/JBig2_SddProc.cpp
index 52aef2b37f..edfc074003 100644
--- a/core/src/fxcodec/jbig2/JBig2_SddProc.cpp
+++ b/core/src/fxcodec/jbig2/JBig2_SddProc.cpp
@@ -266,7 +266,7 @@ CJBig2_SymbolDict* CJBig2_SDDProc::decode_Arith(
   for (I = 0; I < SDNUMINSYMS + SDNUMNEWSYMS; I++) {
     if (EXFLAGS[I] && J < SDNUMEXSYMS) {
       if (I < SDNUMINSYMS) {
-        pDict->AddImage(new CJBig2_Image(*SDINSYMS[I]));
+        pDict->AddImage(SDINSYMS[I] ? new CJBig2_Image(*SDINSYMS[I]) : nullptr);
       } else {
         pDict->AddImage(SDNEWSYMS[I - SDNUMINSYMS]);
       }
@@ -604,7 +604,7 @@ CJBig2_SymbolDict* CJBig2_SDDProc::decode_Huffman(
   for (I = 0; I < SDNUMINSYMS + SDNUMNEWSYMS; I++) {
     if (EXFLAGS[I] && J < SDNUMEXSYMS) {
       if (I < SDNUMINSYMS) {
-        pDict->AddImage(new CJBig2_Image(*SDINSYMS[I]));
+        pDict->AddImage(SDINSYMS[I] ? new CJBig2_Image(*SDINSYMS[I]) : nullptr);
       } else {
         pDict->AddImage(SDNEWSYMS[I - SDNUMINSYMS]);
       }