Convert find markers to Optionals in CPDF_TextPageFind

Currently these use -1 as a special value to indicate not set. This
creates the same issues that FX_STRNPOS created for converting
FX_STRSIZE to size_t, so this code has been rewritten.

BUG=pdfium:828

Change-Id: Iaaa96af0dcb2eb8b600f3ea39060a398ac9a3800
Reviewed-on: https://pdfium-review.googlesource.com/12130
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

1 files changed, 8 insertions, 6 deletions

diff --git a/core/fpdftext/cpdf_textpagefind.h b/core/fpdftext/cpdf_textpagefind.h
index ed0620605a..cf8d3d1702 100644
--- a/core/fpdftext/cpdf_textpagefind.h
+++ b/core/fpdftext/cpdf_textpagefind.h
@@ -13,6 +13,7 @@
 #include "core/fxcrt/fx_coordinates.h"
 #include "core/fxcrt/fx_string.h"
 #include "core/fxcrt/fx_system.h"
+#include "third_party/base/optional.h"
 
 class CPDF_TextPage;
 
@@ -21,7 +22,9 @@ class CPDF_TextPageFind {
   explicit CPDF_TextPageFind(const CPDF_TextPage* pTextPage);
   ~CPDF_TextPageFind();
 
-  bool FindFirst(const CFX_WideString& findwhat, int flags, int startPos = 0);
+  bool FindFirst(const CFX_WideString& findwhat,
+                 int flags,
+                 pdfium::Optional<FX_STRSIZE> startPos);
   bool FindNext();
   bool FindPrev();
   int GetCurOrder() const;
@@ -30,13 +33,12 @@ class CPDF_TextPageFind {
  protected:
   void ExtractFindWhat(const CFX_WideString& findwhat);
   bool IsMatchWholeWord(const CFX_WideString& csPageText,
-                        int startPos,
-                        int endPos);
+                        FX_STRSIZE startPos,
+                        FX_STRSIZE endPos);
   bool ExtractSubString(CFX_WideString& rString,
                         const wchar_t* lpszFullString,
                         int iSubString,
                         wchar_t chSep);
-  CFX_WideString MakeReverse(const CFX_WideString& str);
   int GetCharIndex(int index) const;
 
  private:
@@ -46,8 +48,8 @@ class CPDF_TextPageFind {
   CFX_WideString m_findWhat;
   int m_flags;
   std::vector<CFX_WideString> m_csFindWhatArray;
-  int m_findNextStart;
-  int m_findPreStart;
+  pdfium::Optional<FX_STRSIZE> m_findNextStart;
+  pdfium::Optional<FX_STRSIZE> m_findPreStart;
   bool m_bMatchCase;
   bool m_bMatchWholeWord;
   int m_resStart;