Question

Problem Description

I’m using Expat with a custom C++ wrapper, which I already tested on other projects.
I’m running into problems, because the original data (c_str) is not converted to a std::string in the right way. This concers me, because I did not change the source of the wrapper.

It seems like the string gets null-terminated chars after this conversion:

onCharacterData( std::string( pszData, nLength ) ) // --> std::string( char* pszData)

How can I fix this?

Own expat wrapper

// Wrapper defines the class Expat and implements for example:
void XMLCALL Expat::CharacterDataHandler( void *pUserData, const XML_Char *pszData,
                                          int nLength )
{
  Expat* pThis = static_cast<Expat*>( pUserData );

  // XML_Char is char, therefore this call contains i.e.: std::string("hello", 5) 
  pThis->onCharacterData( std::string( pszData, nLength ) );
}

Custom parser

// Parser is defined as: class Parser : Expat
void Parser::onCharacterData(const std::string& data )
{
  // data is no longer char*, but a std::string.
  // It seems to contain \0 after each character which is wrong!

  // [...]
}

Character data within the expat wrapper (char*)

Character data within the parser (std::string)

Answer 1

Your pszData appears to be in some implementation-specific Unicode-derived format, where each “character” takes up two chars.

This means the source data is broken; it should have been a wchar_t buffer, perhaps.