Getting rid of more (FX_LPCWSTR) casts and fixing two bugs revealed by this.

Since casts to FX_LPCWSTR have been shown to hide bugs I tried removing
more of them, targeting those places where a cast was used to force a
conversion from CFX_WideString to FX_LPCWSTR, replacing these casts with
calls to the newly added .c_str() function. This revealed two places
where the cast was hiding a bug -- where ->c_str() was required instead!

This removes ~33 FX_LPCWSTR casts and there are ~31 left, many of which
will go away in some future change.

Also includes this change:

Removing unnecessary casts from wchar_t* to wchar_t*, by various names.

Original patch from Bruce Dawson(brucedawson@chromium.org)

R=bo_xu@foxitsoftware.com, tsepez@chromium.org

Review URL: https://codereview.chromium.org/733693003

9 files changed, 22 insertions, 20 deletions

diff --git a/core/include/fxcrt/fx_string.h b/core/include/fxcrt/fx_string.h
index 364c510f73..47e8ecdf1e 100644
--- a/core/include/fxcrt/fx_string.h
+++ b/core/include/fxcrt/fx_string.h
@@ -640,9 +640,16 @@ public:
 
     static FX_STRSIZE       WStringLength(const unsigned short* str);
 
+    // Explicit conversion to raw string
+    FX_LPCWSTR c_str() const
+    {
+        return m_pData ? m_pData->m_String : L"";
+    }
+
+    // Implicit conversion to C-style wide string -- deprecated
     operator FX_LPCWSTR() const
     {
-        return m_pData ? m_pData->m_String : (FX_WCHAR*)L"";
+        return m_pData ? m_pData->m_String : L"";
     }
 
     void					Empty();
@@ -762,12 +769,12 @@ protected:
 };
 inline CFX_WideStringC::CFX_WideStringC(const CFX_WideString& src)
 {
-    m_Ptr = (FX_LPCWSTR)src;
+    m_Ptr = src.c_str();
     m_Length = src.GetLength();
 }
 inline CFX_WideStringC& CFX_WideStringC::operator = (const CFX_WideString& src)
 {
-    m_Ptr = (FX_LPCWSTR)src;
+    m_Ptr = src.c_str();
     m_Length = src.GetLength();
     return *this;
 }
@@ -841,6 +848,6 @@ inline CFX_ByteString	FX_UTF8Encode(FX_WSTR wsStr)
 }
 inline CFX_ByteString	FX_UTF8Encode(const CFX_WideString &wsStr)
 {
-    return FX_UTF8Encode((FX_LPCWSTR)wsStr, wsStr.GetLength());
+    return FX_UTF8Encode(wsStr.c_str(), wsStr.GetLength());
 }
 #endif
diff --git a/core/src/fpdfapi/fpdf_font/fpdf_font.cpp b/core/src/fpdfapi/fpdf_font/fpdf_font.cpp
index 36b6ce2b5b..dd646ca113 100644
--- a/core/src/fpdfapi/fpdf_font/fpdf_font.cpp
+++ b/core/src/fpdfapi/fpdf_font/fpdf_font.cpp
@@ -228,7 +228,7 @@ CFX_ByteString CPDF_Font::EncodeString(const CFX_WideString& str) const
     CFX_ByteString result;
     int src_len = str.GetLength();
     FX_LPSTR dest_buf = result.GetBuffer(src_len * 2);
-    FX_LPCWSTR src_buf = str;
+    FX_LPCWSTR src_buf = str.c_str();
     int dest_pos = 0;
     for (int src_pos = 0; src_pos < src_len; src_pos ++) {
         FX_DWORD charcode = CharCodeFromUnicode(src_buf[src_pos]);
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.cpp
index dd4eeddc17..e431c6ad3c 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.cpp
@@ -175,9 +175,9 @@ void FPDF_FileSpec_SetWin32Path(CPDF_Object* pFileSpec, const CFX_WideString& fi
         if (filepath[2] != '\\') {
             result += '/';
         }
-        result += ChangeSlash((FX_LPCWSTR)filepath + 2);
+        result += ChangeSlash(filepath.c_str() + 2);
     } else if (filepath.GetLength() > 1 && filepath[0] == '\\' && filepath[1] == '\\') {
-        result = ChangeSlash((FX_LPCWSTR)filepath + 1);
+        result = ChangeSlash(filepath.c_str() + 1);
     } else {
         result = ChangeSlash(filepath);
     }
@@ -217,7 +217,7 @@ CFX_WideString	FPDF_FileSpec_GetWin32Path(const CPDF_Object* pFileSpec)
         CFX_WideString result;
         result += wsFileName[1];
         result += ':';
-        result += ChangeSlash(((FX_LPCWSTR)wsFileName) + 2);
+        result += ChangeSlash(wsFileName.c_str() + 2);
         return result;
     } else {
         CFX_WideString result;
diff --git a/core/src/fpdfdoc/doc_form.cpp b/core/src/fpdfdoc/doc_form.cpp
index 821b9981b8..6b7e6bf2d6 100644
--- a/core/src/fpdfdoc/doc_form.cpp
+++ b/core/src/fpdfdoc/doc_form.cpp
@@ -161,7 +161,7 @@ CFieldTree::_Node *CFieldTree::_Lookup(_Node *pParent, const CFX_WideString &sho
     for (int i = 0; i < ptr_array.GetSize(); i ++) {
         _Node *pNode = (_Node *)ptr_array[i];
         if (pNode->short_name.GetLength() == short_name.GetLength() &&
-                FXSYS_memcmp32((FX_LPCWSTR)pNode->short_name, (FX_LPCWSTR)short_name, short_name.GetLength()*sizeof(FX_WCHAR)) == 0) {
+                FXSYS_memcmp32(pNode->short_name.c_str(), short_name.c_str(), short_name.GetLength()*sizeof(FX_WCHAR)) == 0) {
             return pNode;
         }
     }
diff --git a/core/src/fxcrt/fx_basic_bstring.cpp b/core/src/fxcrt/fx_basic_bstring.cpp
index 60153fa45a..c54148d799 100644
--- a/core/src/fxcrt/fx_basic_bstring.cpp
+++ b/core/src/fxcrt/fx_basic_bstring.cpp
@@ -971,7 +971,7 @@ CFX_ByteString CFX_ByteString::FromUnicode(FX_LPCWSTR str, FX_STRSIZE len)
 }
 CFX_ByteString CFX_ByteString::FromUnicode(const CFX_WideString& str)
 {
-    return FromUnicode((FX_LPCWSTR)str, str.GetLength());
+    return FromUnicode(str.c_str(), str.GetLength());
 }
 void CFX_ByteString::ConvertFrom(const CFX_WideString& str, CFX_CharMap* pCharMap)
 {
diff --git a/core/src/fxcrt/fx_basic_buffer.cpp b/core/src/fxcrt/fx_basic_buffer.cpp
index 1734423253..b208142d92 100644
--- a/core/src/fxcrt/fx_basic_buffer.cpp
+++ b/core/src/fxcrt/fx_basic_buffer.cpp
@@ -192,7 +192,7 @@ CFX_WideTextBuf& CFX_WideTextBuf::operator << (FX_WSTR str)
 }
 CFX_WideTextBuf& CFX_WideTextBuf::operator << (const CFX_WideString &str)
 {
-    AppendBlock((FX_LPCWSTR)str, str.GetLength() * sizeof(FX_WCHAR));
+    AppendBlock(str.c_str(), str.GetLength() * sizeof(FX_WCHAR));
     return *this;
 }
 CFX_WideTextBuf& CFX_WideTextBuf::operator << (int i)
diff --git a/core/src/fxcrt/fx_extension.cpp b/core/src/fxcrt/fx_extension.cpp
index 7ff6b062b4..6e82ab3d5c 100644
--- a/core/src/fxcrt/fx_extension.cpp
+++ b/core/src/fxcrt/fx_extension.cpp
@@ -146,7 +146,7 @@ FX_FLOAT FXSYS_strtof(FX_LPCSTR pcsStr, FX_INT32 iLength, FX_INT32 *pUsedLen)
         iLength = (FX_INT32)FXSYS_strlen(pcsStr);
     }
     CFX_WideString ws = CFX_WideString::FromLocal(pcsStr, iLength);
-    return FXSYS_wcstof((FX_LPCWSTR)ws, iLength, pUsedLen);
+    return FXSYS_wcstof(ws.c_str(), iLength, pUsedLen);
 }
 FX_FLOAT FXSYS_wcstof(FX_LPCWSTR pwsStr, FX_INT32 iLength, FX_INT32 *pUsedLen)
 {
diff --git a/core/src/fxcrt/fx_xml_parser.cpp b/core/src/fxcrt/fx_xml_parser.cpp
index 26c6540350..8049a5587e 100644
--- a/core/src/fxcrt/fx_xml_parser.cpp
+++ b/core/src/fxcrt/fx_xml_parser.cpp
@@ -670,18 +670,13 @@ FX_BOOL CXML_Element::GetAttrValue(FX_BSTR name, CFX_WideString& attribute) cons
 {
     CFX_ByteStringC bsSpace, bsName;
     FX_XML_SplitQualifiedName(name, bsSpace, bsName);
-    const CFX_WideString* pValue = m_AttrMap.Lookup(bsSpace, bsName);
-    if (pValue) {
-        attribute = CFX_WideString((FX_LPCWSTR)pValue, pValue->GetLength());
-        return TRUE;
-    }
-    return FALSE;
+    return GetAttrValue(bsSpace, bsName, attribute);
 }
 FX_BOOL CXML_Element::GetAttrValue(FX_BSTR space, FX_BSTR name, CFX_WideString& attribute) const
 {
     const CFX_WideString* pValue = m_AttrMap.Lookup(space, name);
     if (pValue) {
-        attribute = CFX_WideString((FX_LPCWSTR)pValue, pValue->GetLength());
+        attribute = *pValue;
         return TRUE;
     }
     return FALSE;
diff --git a/core/src/fxcrt/fxcrt_platforms.cpp b/core/src/fxcrt/fxcrt_platforms.cpp
index e14e362079..1c47ee6c9b 100644
--- a/core/src/fxcrt/fxcrt_platforms.cpp
+++ b/core/src/fxcrt/fxcrt_platforms.cpp
@@ -56,7 +56,7 @@ FX_BOOL CFXCRT_FileAccess_CRT::Open(FX_WSTR fileName, FX_DWORD dwMode)
     }
     CFX_WideString strMode;
     FXCRT_GetFileModeString(dwMode, strMode);
-    m_hFile = FXSYS_wfopen(fileName.GetPtr(), (FX_LPCWSTR)strMode);
+    m_hFile = FXSYS_wfopen(fileName.GetPtr(), strMode.c_str());
     return m_hFile != NULL;
 }
 void CFXCRT_FileAccess_CRT::Close()