Make down-conversion explicit from CFX_ByteString to CFX_ByteStringC.

Having this happen implicitly can be dangerous because the lifetime
has to be considered; we should have caught the "red bots" in
https://codereview.chromium.org/1847333004/#ps60001 at compile time.

Review URL: https://codereview.chromium.org/1853233002

17 files changed, 65 insertions, 49 deletions

diff --git a/core/fpdfapi/fpdf_edit/cpdf_pagecontentgenerator.cpp b/core/fpdfapi/fpdf_edit/cpdf_pagecontentgenerator.cpp
index 6c5339128b..af79fd31c1 100644
--- a/core/fpdfapi/fpdf_edit/cpdf_pagecontentgenerator.cpp
+++ b/core/fpdfapi/fpdf_edit/cpdf_pagecontentgenerator.cpp
@@ -74,12 +74,13 @@ CFX_ByteString CPDF_PageContentGenerator::RealizeResource(
   int idnum = 1;
   while (1) {
     name.Format("FX%c%d", szType[0], idnum);
-    if (!pResList->KeyExist(name)) {
+    if (!pResList->KeyExist(name.AsByteStringC())) {
       break;
     }
     idnum++;
   }
-  pResList->AddReference(name, m_pDocument, pResourceObj->GetObjNum());
+  pResList->AddReference(name.AsByteStringC(), m_pDocument,
+                         pResourceObj->GetObjNum());
   return name;
 }
 void CPDF_PageContentGenerator::ProcessImage(CFX_ByteTextBuf& buf,
diff --git a/core/fpdfapi/fpdf_edit/fpdf_edit_create.cpp b/core/fpdfapi/fpdf_edit/fpdf_edit_create.cpp
index 21934d35c4..323602b0e1 100644
--- a/core/fpdfapi/fpdf_edit/fpdf_edit_create.cpp
+++ b/core/fpdfapi/fpdf_edit/fpdf_edit_create.cpp
@@ -54,7 +54,7 @@ int32_t PDF_CreatorAppendObject(const CPDF_Object* pObj,
       if (pFile->AppendString(" ") < 0) {
         return -1;
       }
-      if ((len = pFile->AppendString(pObj->GetString())) < 0) {
+      if ((len = pFile->AppendString(pObj->GetString().AsByteStringC())) < 0) {
         return -1;
       }
       offset += len + 1;
@@ -62,7 +62,8 @@ int32_t PDF_CreatorAppendObject(const CPDF_Object* pObj,
     case CPDF_Object::STRING: {
       CFX_ByteString str = pObj->GetString();
       FX_BOOL bHex = pObj->AsString()->IsHex();
-      if ((len = pFile->AppendString(PDF_EncodeString(str, bHex))) < 0) {
+      if ((len = pFile->AppendString(
+               PDF_EncodeString(str, bHex).AsByteStringC())) < 0) {
         return -1;
       }
       offset += len;
@@ -73,7 +74,8 @@ int32_t PDF_CreatorAppendObject(const CPDF_Object* pObj,
         return -1;
       }
       CFX_ByteString str = pObj->GetString();
-      if ((len = pFile->AppendString(PDF_NameEncode(str))) < 0) {
+      if ((len = pFile->AppendString(PDF_NameEncode(str).AsByteStringC())) <
+          0) {
         return -1;
       }
       offset += len + 1;
@@ -132,7 +134,8 @@ int32_t PDF_CreatorAppendObject(const CPDF_Object* pObj,
         if (pFile->AppendString("/") < 0) {
           return -1;
         }
-        if ((len = pFile->AppendString(PDF_NameEncode(key))) < 0) {
+        if ((len = pFile->AppendString(PDF_NameEncode(key).AsByteStringC())) <
+            0) {
           return -1;
         }
         offset += len + 1;
@@ -211,7 +214,8 @@ int32_t PDF_CreatorWriteTrailer(CPDF_Document* pDocument,
       if (pFile->AppendString(("/")) < 0) {
         return -1;
       }
-      if ((len = pFile->AppendString(PDF_NameEncode(key))) < 0) {
+      if ((len = pFile->AppendString(PDF_NameEncode(key).AsByteStringC())) <
+          0) {
         return -1;
       }
       offset += len + 1;
@@ -1114,7 +1118,7 @@ int32_t CPDF_Creator::WriteDirectObj(uint32_t objnum,
       if (m_File.AppendString(" ") < 0) {
         return -1;
       }
-      if ((len = m_File.AppendString(pObj->GetString())) < 0) {
+      if ((len = m_File.AppendString(pObj->GetString().AsByteStringC())) < 0) {
         return -1;
       }
       m_Offset += len + 1;
@@ -1124,7 +1128,7 @@ int32_t CPDF_Creator::WriteDirectObj(uint32_t objnum,
       FX_BOOL bHex = pObj->AsString()->IsHex();
       if (!m_pCryptoHandler || !bEncrypt) {
         CFX_ByteString content = PDF_EncodeString(str, bHex);
-        if ((len = m_File.AppendString(content)) < 0) {
+        if ((len = m_File.AppendString(content.AsByteStringC())) < 0) {
           return -1;
         }
         m_Offset += len;
@@ -1136,7 +1140,7 @@ int32_t CPDF_Creator::WriteDirectObj(uint32_t objnum,
       CFX_ByteString content = PDF_EncodeString(
           CFX_ByteString((const FX_CHAR*)encryptor.m_pData, encryptor.m_dwSize),
           bHex);
-      if ((len = m_File.AppendString(content)) < 0) {
+      if ((len = m_File.AppendString(content.AsByteStringC())) < 0) {
         return -1;
       }
       m_Offset += len;
@@ -1176,7 +1180,8 @@ int32_t CPDF_Creator::WriteDirectObj(uint32_t objnum,
         return -1;
       }
       CFX_ByteString str = pObj->GetString();
-      if ((len = m_File.AppendString(PDF_NameEncode(str))) < 0) {
+      if ((len = m_File.AppendString(PDF_NameEncode(str).AsByteStringC())) <
+          0) {
         return -1;
       }
       m_Offset += len + 1;
@@ -1240,7 +1245,8 @@ int32_t CPDF_Creator::WriteDirectObj(uint32_t objnum,
         if (m_File.AppendString("/") < 0) {
           return -1;
         }
-        if ((len = m_File.AppendString(PDF_NameEncode(key))) < 0) {
+        if ((len = m_File.AppendString(PDF_NameEncode(key).AsByteStringC())) <
+            0) {
           return -1;
         }
         m_Offset += len + 1;
@@ -1642,7 +1648,7 @@ int32_t CPDF_Creator::WriteDoc_Stage3(IFX_Pause* pPause) {
         str = m_ObjectOffset.GetPtrAt(1)
                   ? "xref\r\n"
                   : "xref\r\n0 1\r\n0000000000 65535 f\r\n";
-        if (m_File.AppendString(str) < 0) {
+        if (m_File.AppendString(str.AsByteStringC()) < 0) {
           return -1;
         }
         m_Pos = (void*)(uintptr_t)1;
@@ -1771,7 +1777,7 @@ int32_t CPDF_Creator::WriteDoc_Stage4(IFX_Pause* pPause) {
         if (m_File.AppendString(("/")) < 0) {
           return -1;
         }
-        if (m_File.AppendString(PDF_NameEncode(key)) < 0) {
+        if (m_File.AppendString(PDF_NameEncode(key).AsByteStringC()) < 0) {
           return -1;
         }
         if (pValue->GetObjNum()) {
diff --git a/core/fpdfapi/fpdf_edit/fpdf_edit_doc.cpp b/core/fpdfapi/fpdf_edit/fpdf_edit_doc.cpp
index 0f75cb04a8..d70c04c690 100644
--- a/core/fpdfapi/fpdf_edit/fpdf_edit_doc.cpp
+++ b/core/fpdfapi/fpdf_edit/fpdf_edit_doc.cpp
@@ -1124,7 +1124,7 @@ CPDF_Font* CPDF_Document::AddStandardFont(const FX_CHAR* font,
   CFX_ByteString name(font);
   if (PDF_GetStandardFontName(&name) < 0)
     return nullptr;
-  return GetPageData()->GetStandardFont(name, pEncoding);
+  return GetPageData()->GetStandardFont(name.AsByteStringC(), pEncoding);
 }
 
 void CPDF_Document::DeletePage(int iPage) {
diff --git a/core/fpdfapi/fpdf_font/fpdf_font.cpp b/core/fpdfapi/fpdf_font/fpdf_font.cpp
index ce2390ec08..aff2b72960 100644
--- a/core/fpdfapi/fpdf_font/fpdf_font.cpp
+++ b/core/fpdfapi/fpdf_font/fpdf_font.cpp
@@ -233,9 +233,9 @@ void CPDF_ToUnicodeMap::Load(CPDF_Stream* pStream) {
           break;
         }
         high = parser.GetWord();
-        uint32_t lowcode = StringToCode(low);
-        uint32_t highcode =
-            (lowcode & 0xffffff00) | (StringToCode(high) & 0xff);
+        uint32_t lowcode = StringToCode(low.AsByteStringC());
+        uint32_t highcode = (lowcode & 0xffffff00) |
+                            (StringToCode(high.AsByteStringC()) & 0xff);
         if (highcode == (uint32_t)-1) {
           break;
         }
@@ -243,7 +243,7 @@ void CPDF_ToUnicodeMap::Load(CPDF_Stream* pStream) {
         if (start == "[") {
           for (uint32_t code = lowcode; code <= highcode; code++) {
             CFX_ByteString dest = parser.GetWord();
-            CFX_WideString destcode = StringToWideString(dest);
+            CFX_WideString destcode = StringToWideString(dest.AsByteStringC());
             int len = destcode.GetLength();
             if (len == 0) {
               continue;
@@ -258,11 +258,11 @@ void CPDF_ToUnicodeMap::Load(CPDF_Stream* pStream) {
           }
           parser.GetWord();
         } else {
-          CFX_WideString destcode = StringToWideString(start);
+          CFX_WideString destcode = StringToWideString(start.AsByteStringC());
           int len = destcode.GetLength();
           uint32_t value = 0;
           if (len == 1) {
-            value = StringToCode(start);
+            value = StringToCode(start.AsByteStringC());
             for (uint32_t code = lowcode; code <= highcode; code++) {
               m_Map[code] = value++;
             }
diff --git a/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp b/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp
index 2552a3c0a6..fb3707f498 100644
--- a/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp
+++ b/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp
@@ -440,7 +440,7 @@ void CPDF_CMapParser::ParseWord(const CFX_ByteStringC& word) {
       }
       if (m_CodeSeq % 2) {
         CMap_CodeRange range;
-        if (CMap_GetCodeRange(range, m_LastWord, word)) {
+        if (CMap_GetCodeRange(range, m_LastWord.AsByteStringC(), word)) {
           m_CodeRanges.Add(range);
         }
       }
diff --git a/core/fpdfapi/fpdf_page/cpdf_allstates.cpp b/core/fpdfapi/fpdf_page/cpdf_allstates.cpp
index 159de584ee..d81a488d20 100644
--- a/core/fpdfapi/fpdf_page/cpdf_allstates.cpp
+++ b/core/fpdfapi/fpdf_page/cpdf_allstates.cpp
@@ -115,7 +115,7 @@ void CPDF_AllStates::ProcessExtGS(CPDF_Dictionary* pGS,
         CFX_ByteString mode =
             pArray ? pArray->GetStringAt(0) : pObject->GetString();
 
-        pGeneralState->SetBlendMode(mode);
+        pGeneralState->SetBlendMode(mode.AsByteStringC());
         if (pGeneralState->m_BlendType > FXDIB_BLEND_MULTIPLY) {
           pParser->GetPageObjectHolder()->SetBackgroundAlphaNeeded(TRUE);
         }
diff --git a/core/fpdfapi/fpdf_page/fpdf_page_doc.cpp b/core/fpdfapi/fpdf_page/fpdf_page_doc.cpp
index 9f4ad5a7d5..758ce940d2 100644
--- a/core/fpdfapi/fpdf_page/fpdf_page_doc.cpp
+++ b/core/fpdfapi/fpdf_page/fpdf_page_doc.cpp
@@ -331,7 +331,7 @@ CPDF_ColorSpace* CPDF_DocPageData::GetColorSpace(
     if (!pCS && pResources) {
       CPDF_Dictionary* pList = pResources->GetDictBy("ColorSpace");
       if (pList) {
-        pCSObj = pList->GetDirectObjectBy(name);
+        pCSObj = pList->GetDirectObjectBy(name.AsByteStringC());
         return GetColorSpace(pCSObj, nullptr);
       }
     }
diff --git a/core/fpdfapi/fpdf_page/fpdf_page_parser.cpp b/core/fpdfapi/fpdf_page/fpdf_page_parser.cpp
index daddb9f05b..4f304a3b3b 100644
--- a/core/fpdfapi/fpdf_page/fpdf_page_parser.cpp
+++ b/core/fpdfapi/fpdf_page/fpdf_page_parser.cpp
@@ -566,9 +566,9 @@ void CPDF_StreamContentParser::Handle_BeginImage() {
     if (!key.IsEmpty()) {
       uint32_t dwObjNum = pObj ? pObj->GetObjNum() : 0;
       if (dwObjNum)
-        pDict->SetAtReference(key, m_pDocument, dwObjNum);
+        pDict->SetAtReference(key.AsByteStringC(), m_pDocument, dwObjNum);
       else
-        pDict->SetAt(key, pObj.release());
+        pDict->SetAt(key.AsByteStringC(), pObj.release());
     }
   }
   PDF_ReplaceAbbr(pDict);
@@ -721,7 +721,8 @@ void CPDF_StreamContentParser::Handle_ExecuteXObject() {
       pList = m_pPageResources->GetDictBy("XObject");
     if (!pList)
       return;
-    CPDF_Reference* pRes = ToReference(pList->GetObjectBy(name));
+    CPDF_Reference* pRes =
+        ToReference(pList->GetObjectBy(name.AsByteStringC()));
     if (!pRes)
       return;
 
@@ -1257,7 +1258,7 @@ CPDF_Object* CPDF_StreamContentParser::FindResourceObj(
     if (!pList) {
       return NULL;
     }
-    CPDF_Object* pRes = pList->GetDirectObjectBy(name);
+    CPDF_Object* pRes = pList->GetDirectObjectBy(name.AsByteStringC());
     return pRes;
   }
   CPDF_Dictionary* pList = m_pResources->GetDictBy(type);
@@ -1269,10 +1270,10 @@ CPDF_Object* CPDF_StreamContentParser::FindResourceObj(
     if (!pList) {
       return NULL;
     }
-    CPDF_Object* pRes = pList->GetDirectObjectBy(name);
+    CPDF_Object* pRes = pList->GetDirectObjectBy(name.AsByteStringC());
     return pRes;
   }
-  CPDF_Object* pRes = pList->GetDirectObjectBy(name);
+  CPDF_Object* pRes = pList->GetDirectObjectBy(name.AsByteStringC());
   return pRes;
 }
 
@@ -1763,8 +1764,9 @@ void PDF_ReplaceAbbr(CPDF_Object* pObj) {
       for (const auto& it : *pDict) {
         CFX_ByteString key = it.first;
         CPDF_Object* value = it.second;
-        CFX_ByteStringC fullname = PDF_FindFullName(
-            PDF_InlineKeyAbbr, FX_ArraySize(PDF_InlineKeyAbbr), key);
+        CFX_ByteStringC fullname =
+            PDF_FindFullName(PDF_InlineKeyAbbr, FX_ArraySize(PDF_InlineKeyAbbr),
+                             key.AsByteStringC());
         if (!fullname.IsEmpty()) {
           AbbrReplacementOp op;
           op.is_replace_key = true;
@@ -1777,7 +1779,8 @@ void PDF_ReplaceAbbr(CPDF_Object* pObj) {
         if (value->IsName()) {
           CFX_ByteString name = value->GetString();
           fullname = PDF_FindFullName(PDF_InlineValueAbbr,
-                                      FX_ArraySize(PDF_InlineValueAbbr), name);
+                                      FX_ArraySize(PDF_InlineValueAbbr),
+                                      name.AsByteStringC());
           if (!fullname.IsEmpty()) {
             AbbrReplacementOp op;
             op.is_replace_key = false;
@@ -1791,9 +1794,9 @@ void PDF_ReplaceAbbr(CPDF_Object* pObj) {
       }
       for (const auto& op : replacements) {
         if (op.is_replace_key)
-          pDict->ReplaceKey(op.key, op.replacement);
+          pDict->ReplaceKey(op.key.AsByteStringC(), op.replacement);
         else
-          pDict->SetAtName(op.key, op.replacement);
+          pDict->SetAtName(op.key.AsByteStringC(), op.replacement);
       }
       break;
     }
@@ -1804,7 +1807,8 @@ void PDF_ReplaceAbbr(CPDF_Object* pObj) {
         if (pElement->IsName()) {
           CFX_ByteString name = pElement->GetString();
           CFX_ByteStringC fullname = PDF_FindFullName(
-              PDF_InlineValueAbbr, FX_ArraySize(PDF_InlineValueAbbr), name);
+              PDF_InlineValueAbbr, FX_ArraySize(PDF_InlineValueAbbr),
+              name.AsByteStringC());
           if (!fullname.IsEmpty()) {
             pArray->SetAt(i, new CPDF_Name(fullname));
           }
diff --git a/core/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp b/core/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp
index a5db2d6d20..a3c88c00df 100644
--- a/core/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp
+++ b/core/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp
@@ -427,7 +427,7 @@ CPDF_Object* CPDF_StreamParser::ReadNextObject(FX_BOOL bAllowNestedArray,
         return nullptr;
       }
       if (!key.IsEmpty()) {
-        pDict->SetAt(key, pObj);
+        pDict->SetAt(key.AsByteStringC(), pObj);
       } else {
         pObj->Release();
       }
diff --git a/core/fpdfapi/fpdf_parser/cpdf_name.cpp b/core/fpdfapi/fpdf_parser/cpdf_name.cpp
index db37754b66..a7adf1b3d6 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_name.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_name.cpp
@@ -29,7 +29,7 @@ CFX_ByteString CPDF_Name::GetString() const {
 }
 
 CFX_ByteStringC CPDF_Name::GetConstString() const {
-  return CFX_ByteStringC(m_Name);
+  return m_Name.AsByteStringC();
 }
 
 void CPDF_Name::SetString(const CFX_ByteString& str) {
diff --git a/core/fpdfapi/fpdf_parser/cpdf_number.cpp b/core/fpdfapi/fpdf_parser/cpdf_number.cpp
index d2f0503bc1..dbc17d5dd6 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_number.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_number.cpp
@@ -47,7 +47,7 @@ const CPDF_Number* CPDF_Number::AsNumber() const {
 }
 
 void CPDF_Number::SetString(const CFX_ByteString& str) {
-  FX_atonum(str, m_bInteger, &m_Integer);
+  FX_atonum(str.AsByteStringC(), m_bInteger, &m_Integer);
 }
 
 CFX_ByteString CPDF_Number::GetString() const {
diff --git a/core/fpdfapi/fpdf_parser/cpdf_object_unittest.cpp b/core/fpdfapi/fpdf_parser/cpdf_object_unittest.cpp
index 2069a161ea..6c1738d5a6 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_object_unittest.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_object_unittest.cpp
@@ -135,7 +135,7 @@ class PDFObjectsTest : public testing::Test {
           return false;
         for (CPDF_Dictionary::const_iterator it = dict1->begin();
              it != dict1->end(); ++it) {
-          if (!Equal(it->second, dict2->GetObjectBy(it->first)))
+          if (!Equal(it->second, dict2->GetObjectBy(it->first.AsByteStringC())))
             return false;
         }
         return true;
diff --git a/core/fpdfapi/fpdf_parser/cpdf_parser.cpp b/core/fpdfapi/fpdf_parser/cpdf_parser.cpp
index 305401525c..73ca71ef1a 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_parser.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_parser.cpp
@@ -822,10 +822,11 @@ FX_BOOL CPDF_Parser::RebuildCrossRef() {
                           uint32_t dwObjNum =
                               pElement ? pElement->GetObjNum() : 0;
                           if (dwObjNum) {
-                            m_pTrailer->SetAtReference(key, m_pDocument,
-                                                       dwObjNum);
+                            m_pTrailer->SetAtReference(key.AsByteStringC(),
+                                                       m_pDocument, dwObjNum);
                           } else {
-                            m_pTrailer->SetAt(key, pElement->Clone());
+                            m_pTrailer->SetAt(key.AsByteStringC(),
+                                              pElement->Clone());
                           }
                         }
                       }
diff --git a/core/fpdfapi/fpdf_parser/cpdf_standard_security_handler.cpp b/core/fpdfapi/fpdf_parser/cpdf_standard_security_handler.cpp
index ac7667c3ea..9846c40d8f 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_standard_security_handler.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_standard_security_handler.cpp
@@ -166,14 +166,15 @@ FX_BOOL CPDF_StandardSecurityHandler::LoadDict(CPDF_Dictionary* pEncryptDict) {
   m_Revision = pEncryptDict->GetIntegerBy("R");
   m_Permissions = pEncryptDict->GetIntegerBy("P", -1);
   if (m_Version < 4) {
-    return _LoadCryptInfo(pEncryptDict, CFX_ByteString(), m_Cipher, m_KeyLen);
+    return _LoadCryptInfo(pEncryptDict, CFX_ByteStringC(), m_Cipher, m_KeyLen);
   }
   CFX_ByteString stmf_name = pEncryptDict->GetStringBy("StmF");
   CFX_ByteString strf_name = pEncryptDict->GetStringBy("StrF");
   if (stmf_name != strf_name) {
     return FALSE;
   }
-  if (!_LoadCryptInfo(pEncryptDict, strf_name, m_Cipher, m_KeyLen)) {
+  if (!_LoadCryptInfo(pEncryptDict, strf_name.AsByteStringC(), m_Cipher,
+                      m_KeyLen)) {
     return FALSE;
   }
   return TRUE;
@@ -195,7 +196,8 @@ FX_BOOL CPDF_StandardSecurityHandler::LoadDict(CPDF_Dictionary* pEncryptDict,
       return FALSE;
     }
   }
-  if (!_LoadCryptInfo(pEncryptDict, strf_name, cipher, key_len)) {
+  if (!_LoadCryptInfo(pEncryptDict, strf_name.AsByteStringC(), cipher,
+                      key_len)) {
     return FALSE;
   }
   m_Cipher = cipher;
diff --git a/core/fpdfapi/fpdf_parser/cpdf_string.cpp b/core/fpdfapi/fpdf_parser/cpdf_string.cpp
index 9a88e937ab..3f04d125a2 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_string.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_string.cpp
@@ -32,7 +32,7 @@ CFX_ByteString CPDF_String::GetString() const {
 }
 
 CFX_ByteStringC CPDF_String::GetConstString() const {
-  return CFX_ByteStringC(m_String);
+  return m_String.AsByteStringC();
 }
 
 void CPDF_String::SetString(const CFX_ByteString& str) {
diff --git a/core/fpdfapi/fpdf_parser/cpdf_syntax_parser.cpp b/core/fpdfapi/fpdf_parser/cpdf_syntax_parser.cpp
index 5a3db292e0..d04a682b77 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_syntax_parser.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_syntax_parser.cpp
@@ -399,7 +399,7 @@ CPDF_Object* CPDF_SyntaxParser::GetObject(CPDF_IndirectObjectHolder* pObjList,
       }
     }
     m_Pos = SavedPos;
-    return new CPDF_Number(word);
+    return new CPDF_Number(word.AsByteStringC());
   }
 
   if (word == "true" || word == "false")
@@ -521,7 +521,7 @@ CPDF_Object* CPDF_SyntaxParser::GetObjectByStrict(
         return new CPDF_Reference(pObjList, FXSYS_atoui(word));
     }
     m_Pos = SavedPos;
-    return new CPDF_Number(word);
+    return new CPDF_Number(word.AsByteStringC());
   }
 
   if (word == "true" || word == "false")
diff --git a/core/fpdfapi/fpdf_parser/include/cpdf_object.h b/core/fpdfapi/fpdf_parser/include/cpdf_object.h
index 802cbbc638..6cdaaf58fd 100644
--- a/core/fpdfapi/fpdf_parser/include/cpdf_object.h
+++ b/core/fpdfapi/fpdf_parser/include/cpdf_object.h
@@ -46,6 +46,8 @@ class CPDF_Object {
   void Release();
 
   virtual CFX_ByteString GetString() const;
+
+  // Note: |this| must outlive the use of |GetConstString|'s result.
   virtual CFX_ByteStringC GetConstString() const;
   virtual CFX_WideString GetUnicodeText() const;
   virtual FX_FLOAT GetNumber() const;