in the attempt to fix 627393, changed IFX_FileRead's readBlock to return the length it reads

core/fpdfapi/fpdf_parser/cpdf_syntax_parser.cpp

 // Copyright 2016 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 "core/fpdfapi/fpdf_parser/cpdf_syntax_parser.h"
 
 #include <vector>
 
@@ skipping 59 matching lines @@
 
     if ((FX_FILESIZE)(read_pos + read_size) > m_FileLen) {
       if (m_FileLen < (FX_FILESIZE)read_size) {
         read_pos = 0;
         read_size = (uint32_t)m_FileLen;
       } else {
         read_pos = m_FileLen - read_size;
       }
     }
 
-    if (!m_pFileAccess->ReadBlock(m_pFileBuf, read_pos, read_size))
+    if (m_pFileAccess->ReadBlock(m_pFileBuf, read_pos, read_size) !=
+            read_size &&
+        !m_pFileAccess->IsEOF())
       return FALSE;
 
     m_BufOffset = read_pos;
   }
   ch = m_pFileBuf[pos - m_BufOffset];
   m_Pos++;
   return TRUE;
 }
 
 FX_BOOL CPDF_SyntaxParser::GetCharAtBackward(FX_FILESIZE pos, uint8_t& ch) {
@@ skipping 11 matching lines @@
     uint32_t read_size = m_BufSize;
     if ((FX_FILESIZE)(read_pos + read_size) > m_FileLen) {
       if (m_FileLen < (FX_FILESIZE)read_size) {
         read_pos = 0;
         read_size = (uint32_t)m_FileLen;
       } else {
         read_pos = m_FileLen - read_size;
       }
     }
 
-    if (!m_pFileAccess->ReadBlock(m_pFileBuf, read_pos, read_size))
+    if (m_pFileAccess->ReadBlock(m_pFileBuf, read_pos, read_size) !=
+            read_size &&
+        !m_pFileAccess->IsEOF())
       return FALSE;
 
     m_BufOffset = read_pos;
   }
   ch = m_pFileBuf[pos - m_BufOffset];
   return TRUE;
 }
 
 FX_BOOL CPDF_SyntaxParser::ReadBlock(uint8_t* pBuf, uint32_t size) {
-  if (!m_pFileAccess->ReadBlock(pBuf, m_Pos + m_HeaderOffset, size))
+  if (m_pFileAccess->ReadBlock(pBuf, m_Pos + m_HeaderOffset, size) != size &&
+      !m_pFileAccess->IsEOF())
     return FALSE;
   m_Pos += size;
   return TRUE;
 }
 
 void CPDF_SyntaxParser::GetNextWordInternal(bool* bIsNumber) {
   m_WordSize = 0;
   if (bIsNumber)
     *bIsNumber = true;
 
@@ skipping 855 matching lines @@
 }
 
 void CPDF_SyntaxParser::SetEncrypt(
     std::unique_ptr<CPDF_CryptoHandler> pCryptoHandler) {
   m_pCryptoHandler = std::move(pCryptoHandler);
 }
 
 CFX_ByteString CPDF_SyntaxParser::MaybeIntern(const CFX_ByteString& str) {
   return m_pPool ? m_pPool->Intern(str) : str;
 }