Method GetCharacterRef

src/xml/tinyxml2.cpp:334–421

const char* XMLUtil::GetCharacterRef( const char* p, char* value, int* length ) {
    // Presume an entity, and pull it out.
    *length = 0;

    if ( *(p+1) == '#' && *(p+2) ) {
        unsigned long ucs = 0;
        TIXMLASSERT( sizeof( ucs ) >= 4 );
        ptrdiff_t delta = 0;
        unsigned mult = 1;
        static const char SEMICOLON = ';';

        if ( *(p+2) == 'x' ) {
            // Hexadecimal.
            const char* q = p+3;
            if ( !(*q) ) {
                return 0;
            }

            q = strchr( q, SEMICOLON );

            if ( !q ) {
                return 0;
            }
            TIXMLASSERT( *q == SEMICOLON );

            delta = q-p;
            --q;

            while ( *q != 'x' ) {
                unsigned int digit = 0;

                if ( *q >= '0' && *q <= '9' ) {
                    digit = *q - '0';
                } else if ( *q >= 'a' && *q <= 'f' ) {
                    digit = *q - 'a' + 10;
                } else if ( *q >= 'A' && *q <= 'F' ) {
                    digit = *q - 'A' + 10;
                } else {
                    return 0;
                }
                TIXMLASSERT( digit >= 0 && digit < 16);
                TIXMLASSERT( digit == 0 || mult <= UINT_MAX / digit );
                const unsigned int digitScaled = mult * digit;
                TIXMLASSERT( ucs <= ULONG_MAX - digitScaled );
                ucs += digitScaled;
                TIXMLASSERT( mult <= UINT_MAX / 16 );
                mult *= 16;
                --q;
            }
        } else {
            // Decimal.
            const char* q = p+2;
            if ( !(*q) ) {
                return 0;
            }

            q = strchr( q, SEMICOLON );