FileReadUTF16LE skips optional BOM and FileWriteUTF16LE can write a BOM with the /BOM switch

git-svn-id: https://svn.code.sf.net/p/nsis/code/NSIS/trunk@6626 212acab6-be3b-0410-9dea-997c60f758d6

Source/exehead/exec.c

@@ -1370,11 +1370,12 @@ static int NSISCALL ExecuteEntry(entry *entry_)
         DWORD dw;
         int l; // number of bytes to write
         TCHAR *t=var0;
-        if (parm2) // FileWriteByte or FileWriteWord
+        const int writeCodPt = parm2, ansi = EW_FPUTS == which;
+        if (writeCodPt) // FileWriteByte or FileWriteWord
         {
           // Note: In Unicode version, we put a WORD in buf1[0] and will write 1 or 2 bytes, depending on FileWriteByte/Word.
           ((_TUCHAR *)buf1)[0]=(_TUCHAR) GetIntFromParm(1); // FIX_ENDIAN_INT16 needed?
-          l=(which==EW_FPUTS)?1:sizeof(TCHAR);              // Note: This is optimized by the compiler into l=1 for ANSI compilation
+          l=(ansi)?1:sizeof(TCHAR);
         }
 #ifdef _UNICODE
         else if (which==EW_FPUTS)
@@ -1388,10 +1389,16 @@ static int NSISCALL ExecuteEntry(entry *entry_)
         {
           l=mystrlen(GetStringFromParm(0x11))*sizeof(TCHAR);
         }
-        if (!*t || !WriteFile((HANDLE)strtoiptr(t),buf1,l,&dw,NULL))
+        if (*t)
         {
-          exec_error++;
+          const HANDLE hFile = (HANDLE) strtoiptr(t);
+#ifdef _UNICODE
+          if ((ansi | writeCodPt) || !parm3 || SUCCEEDED(UTF16LEBOM(hFile,(INT_PTR)hFile)))
+#endif
+            if (WriteFile(hFile,buf1,l,&dw,NULL))
+              break; // Success
         }
+        exec_error++;
       }
     break;
     case EW_FGETS:
@@ -1433,6 +1440,9 @@ static int NSISCALL ExecuteEntry(entry *entry_)
             else
 #endif
             {
+#ifdef _UNICODE
+              if (!parm3 && 0 == rpos && FAILED(UTF16LEBOM(h,FALSE))) break;
+#endif
               // Read 1 TCHAR (FileReadUTF16LE, (Ansi)FileRead, FileReadWord)
               if (!myReadFile(h,&c,sizeof(TCHAR))) break;
             }

Source/exehead/util.c

@@ -456,6 +456,31 @@ BOOL NSISCALL myReadFile(HANDLE h, LPVOID buf, DWORD cb)
   return r && cb == cbio;
 }
 
+// Reading skips the BOM if present, writing writes it to a empty file
+HRESULT NSISCALL UTF16LEBOM(HANDLE h, INT_PTR ForWrite)
+{
+  DWORD orgpos = SetFilePointer(h, 0, NULL, FILE_CURRENT), cbio;
+  if (0 == orgpos)
+  {
+    BYTE bom[2];
+    if (myReadFile(h, bom, 2) && (0xff == bom[0] && 0xfe == bom[1]))
+    {
+      return S_OK;
+    }
+    else if (ForWrite)
+    {
+      if (0 == SetFilePointer(h, 0, NULL, FILE_CURRENT)) // Is the file empty?
+      {
+        static const BYTE bom16le[] = { 0xff, 0xfe };
+        return (WriteFile(h, bom16le, 2, &cbio, NULL) && 2 == cbio)
+          ? S_OK : E_FAIL;
+      }
+    }
+    SetFilePointer(h, 0, NULL, FILE_BEGIN); // The file may have starting with something that was not a BOM, undo the read
+  }
+  return S_FALSE;
+}
+
 #ifdef NSIS_SUPPORT_MOVEONREBOOT
 #ifndef _WIN64
 /** Modifies the wininit.ini file to rename / delete a file.

Source/exehead/util.h

@@ -44,6 +44,7 @@ TCHAR * NSISCALL mystrstr(TCHAR *a, TCHAR *b);
 WIN32_FIND_DATA * NSISCALL file_exists(TCHAR *buf);
 TCHAR * NSISCALL my_GetTempFileName(TCHAR *buf, const TCHAR *dir);
 BOOL NSISCALL myReadFile(HANDLE h, LPVOID buf, DWORD cb);
+HRESULT NSISCALL UTF16LEBOM(HANDLE h, INT_PTR ForWrite);
 
 //BOOL NSISCALL my_SetWindowText(HWND hWnd, const TCHAR *val);
 #define my_SetWindowText SetWindowText

Source/script.cpp

@@ -5690,11 +5690,17 @@ int CEXEBuild::doCommand(int which_token, LineParser &line)
         ERROR_MSG(_T("Error: %") NPRIs _T(" is only available when building a Unicode installer\n"),  line.gettoken_str(0));
         return PS_ERROR;
       }
-      ent.which=EW_FPUTWS;
-      ent.offsets[0]=GetUserVarIndex(line, 1); // file handle
-      ent.offsets[1]=add_string(line.gettoken_str(2));
-      if (ent.offsets[0]<0) PRINTHELP()
-      SCRIPT_MSG(_T("FileWriteUTF16LE: %") NPRIs _T("->%") NPRIs _T("\n"),line.gettoken_str(2),line.gettoken_str(1));
+      {
+        UINT bom=0, swofs=0;
+        if (!_tcsicmp(_T("/BOM"),line.gettoken_str(swofs+1))) ++bom, ++swofs;
+        if (!_tcsicmp(_T("/NoBOM"),line.gettoken_str(swofs+1))) bom = 0, ++swofs; // Undocumented switch
+        ent.which=EW_FPUTWS;
+        ent.offsets[0]=GetUserVarIndex(line, swofs+1); // file handle
+        ent.offsets[1]=add_string(line.gettoken_str(swofs+2));
+        ent.offsets[3]=bom;
+        if (ent.offsets[0]<0 || line.getnumtokens()-swofs != 3) PRINTHELP()
+        SCRIPT_MSG(_T("FileWriteUTF16LE: %") NPRIs _T("->%") NPRIs _T("\n"),line.gettoken_str(swofs+2),line.gettoken_str(swofs+1));
+      }
     return add_entry(&ent);
     case TOK_FILEREADWORD:
       if (!build_unicode)

Source/tokens.cpp

@@ -99,7 +99,7 @@ static tokenType tokenlist[TOK__LAST] =
 {TOK_FILEWRITEBYTE,_T("FileWriteByte"),2,0,_T("$(user_var: handle input) bytevalue"),TP_CODE},
 #ifdef _UNICODE
 {TOK_FILEREADUTF16LE,_T("FileReadUTF16LE"),2,1,_T("$(user_var: handle input) $(user_var: text output) [maxlen]"),TP_CODE},
-{TOK_FILEWRITEUTF16LE,_T("FileWriteUTF16LE"),2,0,_T("$(user_var: handle input) text"),TP_CODE},
+{TOK_FILEWRITEUTF16LE,_T("FileWriteUTF16LE"),2,1,_T("[/BOM] $(user_var: handle input) text"),TP_CODE},
 {TOK_FILEREADWORD,_T("FileReadWord"),2,0,_T("$(user_var: handle input) $(user_var: wordvalue output)"),TP_CODE},
 {TOK_FILEWRITEWORD,_T("FileWriteWord"),2,0,_T("$(user_var: handle input) wordvalue"),TP_CODE},
 #endif