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

core/fpdfapi/fpdf_parser/cpdf_stream.cpp

Index: core/fpdfapi/fpdf_parser/cpdf_stream.cpp
diff --git a/core/fpdfapi/fpdf_parser/cpdf_stream.cpp b/core/fpdfapi/fpdf_parser/cpdf_stream.cpp
index 3b047205c470c03dc5bad279282850424e680950..30dc6eedfb3cfb4acd32ad96ea7b238079912fd9 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_stream.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_stream.cpp
@@ -103,7 +103,7 @@ FX_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();
 
   if (m_pDataBuf)
     FXSYS_memcpy(buf, m_pDataBuf.get() + offset, size);