From bb9b88b70f8c9caf8f5ee3490ce478315ed9e4f9 Mon Sep 17 00:00:00 2001
From: anders_k <anders_k@212acab6-be3b-0410-9dea-997c60f758d6>
Date: Tue, 8 Oct 2013 18:59:28 +0000
Subject: [PATCH] Fix DupWCFromBytes/CharEncConv optimized return bug when
 converting UTF16LE license file to wchar_t(UTF16LE)

git-svn-id: https://svn.code.sf.net/p/nsis/code/NSIS/trunk@6414 212acab6-be3b-0410-9dea-997c60f758d6
---
 Source/script.cpp | 12 ++++++------
 Source/utf.cpp    |  7 ++++---
 Source/utf.h      |  5 +++--
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/Source/script.cpp b/Source/script.cpp
index 68a565ba..8ff1efef 100644
--- a/Source/script.cpp
+++ b/Source/script.cpp
@@ -991,12 +991,12 @@ int CEXEBuild::LoadLicenseFile(const TCHAR *file, TCHAR** pdata, const TCHAR *cm
   fseek(f,cbBOMOffset,SEEK_SET);
   UINT cbTotalData=sizeof(TCHAR)+cbFileData+sizeof(TCHAR); // SF_*+file+\0
   TCHAR*data=(TCHAR*)malloc(cbTotalData);
+  *pdata=data; // memory will be released by caller
   if (!data)
   {
     ERROR_MSG(_T("Internal compiler error #12345: %s malloc(%d) failed.\n"),cmdname,cbTotalData);
     return PS_ERROR;
   }
-  *pdata=data; // memory will be released by caller
   *((TCHAR*)((char*)data+cbTotalData-sizeof(TCHAR)))=_T('\0');
 
   TCHAR*ldata=data+1;
@@ -1014,16 +1014,16 @@ l_errwcconv:
     ERROR_MSG(_T("%s: wchar_t conversion failed!\n"),cmdname);
     return PS_ERROR;
   }
-  // Create a fake character in the "header" part of the buffer
+  // Create a fake character in the "header" part of the buffer (For DupWCFromBytes)
   char*lichdr=((char*)ldata) - cbcu;
   *((char*)lichdr)='X';
   if (cbcu > 1) *((WORD*)lichdr)='X';
   //BUGBUG: No room: if (cbcu > 2) *((UINT32*)lichdr)='X';
-  wchar_t*wcdata=DupWCFromBytes(lichdr,cbcu+cbFileData,srccp);
+  const bool canOptRet = (char*)data == lichdr;
+  wchar_t*wcdata=DupWCFromBytes(lichdr,cbcu+cbFileData,srccp|(canOptRet?DWCFBF_ALLOWOPTIMIZEDRETURN:0));
   if (!wcdata) goto l_errwcconv;
-  free(data);
-  *pdata=data=wcdata;
-  ldata=data+1;
+  if (wcdata != data) free(data);
+  *pdata=data=wcdata, ldata=data+1;
 
   const bool isRTF=!memcmp(ldata,_T("{\\rtf"),5*sizeof(TCHAR));
   if (isRTF)
diff --git a/Source/utf.cpp b/Source/utf.cpp
index 6c80f679..1a300927 100644
--- a/Source/utf.cpp
+++ b/Source/utf.cpp
@@ -92,14 +92,15 @@ UINT WCFromCodePoint(wchar_t*Dest,UINT cchDest,UINT32 CodPt)
 #endif
 }
 
-wchar_t* DupWCFromBytes(void*Buffer,UINT cbBuffer,WORD SrcCP)
+wchar_t* DupWCFromBytes(void*Buffer,UINT cbBuffer,UINT32 SrcCP)
 {
   /*\
   Converts a buffer encoded with SrcCP to a \0 terminated wchar_t malloc'ed buffer.
   Returns 0 on failure.
   \*/
   CharEncConv cec;
-  if (!cec.Initialize(-1, SrcCP)) return 0;
+  cec.SetAllowOptimizedReturn(!!(SrcCP&DWCFBF_ALLOWOPTIMIZEDRETURN));
+  if (!cec.Initialize(-1, SrcCP&=~DWCFBF_ALLOWOPTIMIZEDRETURN)) return 0;
   wchar_t *pWC = (wchar_t*) cec.Convert(Buffer, cbBuffer);
   return pWC ? (wchar_t*) cec.Detach() : 0;
 }
@@ -183,7 +184,7 @@ void* CharEncConv::Convert(const void*Src, size_t cbSrc, size_t*cbOut)
         if (cbSrc && ((WORD*)Src)[--cbSrc]) ++cbSrc;
         *cbOut = cbSrc * sizeof(wchar_t);
       }
-      return (void*) Src;
+      return (void*) (m_Result = (char*) Src);
     }
 #endif
     char *p = (char*) realloc(m_Result, cbSrc + sizeof(UINT32));
diff --git a/Source/utf.h b/Source/utf.h
index 57ce0174..cfb4e6bd 100644
--- a/Source/utf.h
+++ b/Source/utf.h
@@ -91,7 +91,8 @@ UINT StrLenUTF16(const void*str);
 bool StrSetUTF16LE(tstring&dest, const void*src);
 
 UINT WCFromCodePoint(wchar_t*Dest,UINT cchDest,UINT32 CodPt);
-wchar_t* DupWCFromBytes(void*Buffer,UINT cbBuffer,WORD SrcCP);
+#define DWCFBF_ALLOWOPTIMIZEDRETURN 0x80000000 // DupWCFromBytes can return input Buffer
+wchar_t* DupWCFromBytes(void*Buffer,UINT cbBuffer,UINT32 SrcCP);
 UINT DetectUTFBOM(void*Buffer,UINT cb);
 UINT DetectUTFBOM(FILE*strm);
 WORD GetEncodingFromString(const TCHAR*s, bool&BOM);
@@ -110,7 +111,7 @@ protected:
   static bool IsWE(WORD Encoding) { return (WORD)-1 == Encoding; }
   static bool IsWE(UINT32 Encoding) { return (UINT32)-1 == Encoding; }
 public:
-  CharEncConv() : m_Result(0) {}
+  CharEncConv() : m_Result(0) { SetAllowOptimizedReturn(false); }
   ~CharEncConv() { Close(); }
   void Close()
   {