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

core/fpdfapi/parser/cpdf_stream.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/parser/cpdf_stream.h"
 
 #include "core/fpdfapi/parser/cpdf_dictionary.h"
 #include "core/fpdfapi/parser/cpdf_stream_acc.h"
@@ skipping 87 matching lines @@
     m_pDict.reset(new CPDF_Dictionary());
   m_pDict->SetIntegerFor("Length", size);
   m_pDict->RemoveFor("Filter");
   m_pDict->RemoveFor("DecodeParms");
 }
 
 bool CPDF_Stream::ReadRawData(FX_FILESIZE offset,
                               uint8_t* buf,
                               uint32_t size) const {
   if (m_bMemoryBased && m_pFile)
-    return m_pFile->ReadBlock(buf, offset, size);
+    return m_pFile->ReadBlock(buf, offset, size) == size || m_pFile->IsEOF();

[Tom Sepez, 2016/11/16 18:32:00]

This will return success if a short read at EOF.  Its caller at
https://cs.chromium.org/chromium/src/third_party/pdfium/core/fpdfapi/parser/c...
will continue but will use the full length at
https://cs.chromium.org/chromium/src/third_party/pdfium/core/fpdfapi/parser/c...
for example.

 
   if (m_pDataBuf)
     FXSYS_memcpy(buf, m_pDataBuf.get() + offset, size);
 
   return true;
 }
 
 CFX_WideString CPDF_Stream::GetUnicodeText() const {
   CPDF_StreamAcc stream;
   stream.LoadAllData(this, false);
   return PDF_DecodeText(stream.GetData(), stream.GetSize());
 }