🚀 go-pugleaf

I have the following functions that are called from within the context of a
thread:

//--------------------------------------------------------------------------
-

int  __fastcall TCCSMsgObjectEx::BuildMessageFromString(const AnsiString&
cMessage)
{
  int nSize = cMessage.Length();
  if(FMessageBuffer == NULL || nSize > (int)FMessageSize)
  {
    if(FMessageBuffer)
      free(FMessageBuffer);
    FMessageBuffer = (BYTE*)malloc(nSize);
    if(FMessageBuffer == NULL)
     OutOfMemoryError();
  }
  FMessageSize = nSize;
  memcpy(FMessageBuffer, cMessage.c_str(), nSize);
  return FMessageSize;
}
//--------------------------------------------------------------------------
-

int  __fastcall TCCSMsgObjectEx::BuildMessageFromString(const WideString&
cMessage)
{
  int nSize = ::WideCharToMultiByte(CP_ACP, 0, cMessage.c_bstr(),
cMessage.Length(), 0, 0, NULL, NULL);

  if(nSize <= 0)
    RaiseLastOSError();

  if(FMessageBuffer == NULL || nSize > (int)FMessageSize)
  {
    if(FMessageBuffer)
      free(FMessageBuffer);
    FMessageBuffer = (BYTE*)malloc(nSize);
    if(FMessageBuffer == NULL)
     OutOfMemoryError();
  }
  FMessageSize = nSize;
  nSize = ::WideCharToMultiByte(CP_ACP, 0, cMessage.c_bstr(),
cMessage.Length(), FMessageBuffer, nSize, NULL, NULL);
  if(nSize <= 0)
   RaiseLastOSError();

  return FMessageSize;
}
//--------------------------------------------------------------------------
-

FMessageBuffer (BYTE*) and FMessageSize (int) are internal to the class.

I retrieve a WideString value wValue, and call:

BuildMessageFromString(wValue);

The first call to ::WideCharToMultiByte to get the size of the buffer ALWAYS
returns 0 with GetLastError returning 87- "The Parameter is Incorrect"

If I do the following:

AnsiString cValue = AnsiString(wValue);
BuildMessageFromString(cValue);

then everything works as expected.

wValue is a 54 character string that begins with 12 NULL characters and has
other NULL characters in other positions as well.  The AnsiString cValue is
correct in that it has a length of 54 and scanning the strings yields the
correctly converted characters (which all happen to be ansi anyway.)

So why does ::WideCharToMultiByte fail every time?  If I pass -1 for the
input buffer length, then the fuction suceeds, but sees this as a NULL
string since the first character is a NULL.

The string stored in wValue may get quite large at times and I would like to
avoid the overhead of converting to AnsiString first then storing the
results in the buffer; ::WideCharToMultiByte should just store directly to
the buffer for me, it can't seem to handle my NULL-infested string...

Any ideas?

Mark

Mark