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

3 files changed, 22 insertions, 15 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) {