Add APIs for limited use of document tagged code.

fpdfsdk/fpdfdoc.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 "public/fpdf_doc.h"
 
 #include <memory>
 #include <set>
@@ skipping 46 matching lines @@
   if (!pHolder->get())
     pHolder->reset(new CPDF_LinkList);
   return pHolder->get();
 }
 
 unsigned long Utf16EncodeMaybeCopyAndReturnLength(const CFX_WideString& text,
                                                   void* buffer,
                                                   unsigned long buflen) {
   CFX_ByteString encodedText = text.UTF16LE_Encode();
   unsigned long len = encodedText.GetLength();
-  if (buffer && buflen >= len)
+  if (buffer && len <= buflen)
     FXSYS_memcpy(buffer, encodedText.c_str(), len);
   return len;
 }
 
 }  // namespace
 
 DLLEXPORT FPDF_BOOKMARK STDCALL
 FPDFBookmark_GetFirstChild(FPDF_DOCUMENT document, FPDF_BOOKMARK pDict) {
   CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
@@ skipping 101 matching lines @@
 DLLEXPORT unsigned long STDCALL FPDFAction_GetFilePath(FPDF_ACTION pDict,
                                                        void* buffer,
                                                        unsigned long buflen) {
   unsigned long type = FPDFAction_GetType(pDict);
   if (type != PDFACTION_REMOTEGOTO && type != PDFACTION_LAUNCH)
     return 0;
 
   CPDF_Action action(ToDictionary(static_cast<CPDF_Object*>(pDict)));
   CFX_ByteString path = action.GetFilePath().UTF8Encode();
   unsigned long len = path.GetLength() + 1;
-  if (buffer && buflen >= len)
+  if (buffer && len <= buflen)
     FXSYS_memcpy(buffer, path.c_str(), len);
   return len;
 }
 
 DLLEXPORT unsigned long STDCALL FPDFAction_GetURIPath(FPDF_DOCUMENT document,
                                                       FPDF_ACTION pDict,
                                                       void* buffer,
                                                       unsigned long buflen) {
   if (!pDict)
     return 0;
   CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return 0;
   CPDF_Action action(ToDictionary(static_cast<CPDF_Object*>(pDict)));
   CFX_ByteString path = action.GetURI(pDoc);
   unsigned long len = path.GetLength() + 1;
-  if (buffer && buflen >= len)
+  if (buffer && len <= buflen)
     FXSYS_memcpy(buffer, path.c_str(), len);
   return len;
 }
 
 DLLEXPORT unsigned long STDCALL FPDFDest_GetPageIndex(FPDF_DOCUMENT document,
                                                       FPDF_DEST pDict) {
   if (!pDict)
     return 0;
   CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
@@ skipping 186 matching lines @@
   if (page_index < 0)
     return 0;
 
   // CPDF_PageLabel can deal with NULL |document|.
   CPDF_PageLabel label(CPDFDocumentFromFPDFDocument(document));
   CFX_WideString str;
   if (!label.GetLabel(page_index, &str))
     return 0;
   return Utf16EncodeMaybeCopyAndReturnLength(str, buffer, buflen);
 }