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

8 files changed, 17 insertions, 12 deletions

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;