Remove strange integral constants for "true", "false", "%PDF".

core/fpdfapi/fpdf_parser/fpdf_parser_utility.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 "core/fpdfapi/fpdf_parser/fpdf_parser_utility.h"
 
 #include "core/fpdfapi/fpdf_parser/include/cpdf_array.h"
 #include "core/fpdfapi/fpdf_parser/include/cpdf_dictionary.h"
@@ skipping 51 matching lines @@
     'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
     'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
     'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
     'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
     'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
     'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
     'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
     'R', 'R', 'R', 'R', 'R', 'R', 'R', 'W'};
 
 int32_t GetHeaderOffset(IFX_FileRead* pFile) {
-  // TODO(dsinclair): This is a complicated way of saying %PDF, simplify?
-  const FX_DWORD tag = FXDWORD_FROM_LSBFIRST(0x46445025);
-
   const size_t kBufSize = 4;
   uint8_t buf[kBufSize];
-  int32_t offset = 0;
-  while (offset <= 1024) {
+  for (int32_t offset = 0; offset <= 1024; ++offset) {
     if (!pFile->ReadBlock(buf, offset, kBufSize))
       return -1;
 
-    if (*(FX_DWORD*)buf == tag)
+    if (memcmp(buf, "%PDF", 4) == 0)
       return offset;
-
-    ++offset;
   }
   return -1;
 }
 
 int32_t GetDirectInteger(CPDF_Dictionary* pDict, const CFX_ByteStringC& key) {
   CPDF_Number* pObj = ToNumber(pDict->GetElement(key));
   return pObj ? pObj->GetInteger() : 0;
 }
 
 CFX_ByteString PDF_NameDecode(const CFX_ByteStringC& bstr) {
@@ skipping 124 matching lines @@
       buf.AppendBlock(acc.GetData(), acc.GetSize());
       buf << "\r\nendstream";
       break;
     }
     default:
       ASSERT(FALSE);
       break;
   }
   return buf;
 }