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

core/fxcrt/extension.h

 // 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
 
 #ifndef CORE_FXCRT_EXTENSION_H_
 #define CORE_FXCRT_EXTENSION_H_
 
 #include <algorithm>
@@ skipping 47 matching lines @@
  public:
   explicit CFX_CRTFileStream(std::unique_ptr<IFXCRT_FileAccess> pFA);
   ~CFX_CRTFileStream() override;
 
   // IFX_SeekableStream:
   IFX_SeekableStream* Retain() override;
   void Release() override;
   FX_FILESIZE GetSize() override;
   bool IsEOF() override;
   FX_FILESIZE GetPosition() override;
-  bool ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) override;
+  size_t ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) override;
   size_t ReadBlock(void* buffer, size_t size) override;
   bool WriteBlock(const void* buffer, FX_FILESIZE offset, size_t size) override;
   bool Flush() override;
 
  protected:
   std::unique_ptr<IFXCRT_FileAccess> m_pFile;
   uint32_t m_dwCount;
 };
 
 #define FX_MEMSTREAM_BlockSize (64 * 1024)
 #define FX_MEMSTREAM_Consecutive 0x01
 #define FX_MEMSTREAM_TakeOver 0x02
 
 class CFX_MemoryStream final : public IFX_MemoryStream {
  public:
   explicit CFX_MemoryStream(bool bConsecutive);
   CFX_MemoryStream(uint8_t* pBuffer, size_t nSize, bool bTakeOver);
   ~CFX_MemoryStream() override;
 
   // IFX_MemoryStream
   IFX_SeekableStream* Retain() override;
   void Release() override;
   FX_FILESIZE GetSize() override;
   bool IsEOF() override;
   FX_FILESIZE GetPosition() override;
-  bool ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) override;
+  size_t ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) override;
   size_t ReadBlock(void* buffer, size_t size) override;
   bool WriteBlock(const void* buffer, FX_FILESIZE offset, size_t size) override;
   bool Flush() override;
   bool IsConsecutive() const override;
   void EstimateSize(size_t nInitSize, size_t nGrowSize) override;
   uint8_t* GetBuffer() const override;
   void AttachBuffer(uint8_t* pBuffer,
                     size_t nSize,
                     bool bTakeOver = false) override;
   void DetachBuffer() override;
@@ skipping 27 matching lines @@
   uint32_t mt[MT_N];
 };
 #if _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
 bool FX_GenerateCryptoRandom(uint32_t* pBuffer, int32_t iCount);
 #endif
 #ifdef __cplusplus
 }
 #endif
 
 #endif  // CORE_FXCRT_EXTENSION_H_