Revert "Remove FX_Alloc() null checks now that it can't return NULL."

core/src/fxcodec/codec/fx_codec_jbig.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 "../../../include/fxcodec/fx_codec.h"
 #include "codec_int.h"
 CCodec_Jbig2Context::CCodec_Jbig2Context()
 {
@@ skipping 35 matching lines @@
     }
     return TRUE;
 }
 FX_BOOL CCodec_Jbig2Module::Decode(IFX_FileRead* file_ptr,
                                    FX_DWORD& width, FX_DWORD& height, FX_DWORD& pitch, FX_LPBYTE& dest_buf)
 {
     CJBig2_Context* pContext = NULL;
     CJBig2_Image* dest_image = NULL;
     FX_DWORD src_size = (FX_DWORD)file_ptr->GetSize();
     FX_LPBYTE src_buf = FX_Alloc(FX_BYTE, src_size);
+    if (src_buf == NULL) {
+        return FALSE;
+    }
     int ret = 0;
     if(!file_ptr->ReadBlock(src_buf, 0, src_size)) {
         goto failed;
     }
     pContext = CJBig2_Context::CreateContext(&m_Module, NULL, 0, src_buf, src_size, JBIG2_FILE_STREAM, &m_SymbolDictCache);
     if(pContext == NULL) {
         goto failed;
     }
     ret = pContext->getFirstPage(&dest_image, NULL);
     CJBig2_Context::DestroyContext(pContext);
@@ skipping 57 matching lines @@
         FX_DWORD& width, FX_DWORD& height, FX_DWORD& pitch, FX_LPBYTE& dest_buf, IFX_Pause* pPause)
 {
     if(!pJbig2Context) {
         return FXCODEC_STATUS_ERR_PARAMS;
     }
     CCodec_Jbig2Context* m_pJbig2Context = (CCodec_Jbig2Context*)pJbig2Context;
     m_pJbig2Context->m_bFileReader = TRUE;
     m_pJbig2Context->m_dest_image = NULL;
     m_pJbig2Context->m_src_size = (FX_DWORD)file_ptr->GetSize();
     m_pJbig2Context->m_src_buf = FX_Alloc(FX_BYTE, m_pJbig2Context->m_src_size);
+    if (m_pJbig2Context->m_src_buf == NULL) {
+        return FXCODEC_STATUS_ERR_MEMORY;
+    }
     int ret = 0;
     if(!file_ptr->ReadBlock((void*)m_pJbig2Context->m_src_buf, 0, m_pJbig2Context->m_src_size)) {
         goto failed;
     }
     m_pJbig2Context->m_pContext = CJBig2_Context::CreateContext(&m_Module, NULL, 0, m_pJbig2Context->m_src_buf, m_pJbig2Context->m_src_size, JBIG2_FILE_STREAM, &m_SymbolDictCache, pPause);
     if(m_pJbig2Context->m_pContext == NULL) {
         goto failed;
     }
     ret = m_pJbig2Context->m_pContext->getFirstPage(&m_pJbig2Context->m_dest_image, pPause);
     if(m_pJbig2Context->m_pContext->GetProcessiveStatus() == FXCODEC_STATUS_DECODE_TOBECONTINUE) {
@@ skipping 54 matching lines @@
                 dword_buf[i] = ~dword_buf[i];
             }
             return FXCODEC_STATUS_DECODE_FINISH;
         }
     }
     return m_pJbig2Context->m_pContext->GetProcessiveStatus();
 }