if (!tmpSpec) return nsnull;
nsMsgCreateTempFileSpec(char *tFileName){  if ((!tFileName) || (!*tFileName))    tFileName = "nsmail.tmp";  nsFileSpec *tmpSpec = new nsFileSpec(nsSpecialSystemDirectory(nsSpecialSystemDirectory::OS_TemporaryDirectory));    *tmpSpec += tFileName;  tmpSpec->MakeUnique();  return tmpSpec;}