/*
Original code by Lee Thomason (www.grinninglizard.com)

This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any
damages arising from the use of this software.

Permission is granted to anyone to use this software for any
purpose, including commercial applications, and to alter it and
redistribute it freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must
not claim that you wrote the original software. If you use this
software in a product, an acknowledgment in the product documentation
would be appreciated but is not required.

2. Altered source versions must be plainly marked as such, and
must not be misrepresented as being the original software.

3. This notice may not be removed or altered from any source
distribution.
*/

#include "tinyxml2.h"

#include <new>		// yes, this one new style header, is in the Android SDK.
#if defined(ANDROID_NDK) || defined(__BORLANDC__) || defined(__QNXNTO__)
#   include <stddef.h>
#   include <stdarg.h>
#else
#   include <cstddef>
#   include <cstdarg>
#endif

#if defined(_MSC_VER) && (_MSC_VER >= 1400 ) && (!defined WINCE)
// Microsoft Visual Studio, version 2005 and higher. Not WinCE.
/*int _snprintf_s(char *buffer, size_t sizeOfBuffer, size_t count, const char *format [, argument] ... );*/
static int TIXML_SNPRINTF(char* buffer, const size_t size, const char* format, ...)
{
	va_list va;
	va_start(va, format);
	const int result = vsnprintf_s(buffer, size, _TRUNCATE, format, va);
	va_end(va);
	return result;
}

static int TIXML_VSNPRINTF(char* buffer, const size_t size, const char* format, va_list va)
{
	const int result = vsnprintf_s(buffer, size, _TRUNCATE, format, va);
	return result;
}

#define TIXML_VSCPRINTF	_vscprintf
#define TIXML_SSCANF	sscanf_s
#elif defined _MSC_VER
// Microsoft Visual Studio 2003 and earlier or WinCE
#define TIXML_SNPRINTF	_snprintf
#define TIXML_VSNPRINTF _vsnprintf
#define TIXML_SSCANF	sscanf
#if (_MSC_VER < 1400 ) && (!defined WINCE)
	// Microsoft Visual Studio 2003 and not WinCE.
#define TIXML_VSCPRINTF   _vscprintf // VS2003's C runtime has this, but VC6 C runtime or WinCE SDK doesn't have.
#else
	// Microsoft Visual Studio 2003 and earlier or WinCE.
static inline int TIXML_VSCPRINTF(const char* format, va_list va)
{
	int len = 512;
	for (;;) {
		len = len * 2;
		char* str = new char[len]();
		const int required = _vsnprintf(str, len, format, va);
		delete[] str;
		if (required != -1) {
			TIXMLASSERT(required >= 0);
			len = required;
			break;
		}
	}
	TIXMLASSERT(len >= 0);
	return len;
}
#endif
#else
// GCC version 3 and higher
//#warning( "Using sn* functions." )
#define TIXML_SNPRINTF	snprintf
#define TIXML_VSNPRINTF	vsnprintf
static inline int TIXML_VSCPRINTF(const char* format, va_list va)
{
	int len = vsnprintf(0, 0, format, va);
	TIXMLASSERT(len >= 0);
	return len;
}
#define TIXML_SSCANF   sscanf
#endif


static const char LINE_FEED       = char(0x0a);			// all line endings are normalized to LF
static const char LF              = LINE_FEED;
static const char CARRIAGE_RETURN = char(0x0d);			// CR gets filtered out
static const char CR              = CARRIAGE_RETURN;
static const char SINGLE_QUOTE    = '\'';
static const char DOUBLE_QUOTE    = '\"';

// Bunch of unicode info at:
//		http://www.unicode.org/faq/utf_bom.html
//	ef bb bf (Microsoft "lead bytes") - designates UTF-8

static const unsigned char TIXML_UTF_LEAD_0 = 0xefU;
static const unsigned char TIXML_UTF_LEAD_1 = 0xbbU;
static const unsigned char TIXML_UTF_LEAD_2 = 0xbfU;

namespace tinyxml2 {
struct Entity
{
	const char* pattern;
	int length;
	char value;
};

static const int NUM_ENTITIES              = 5;
static const Entity ENTITIES[NUM_ENTITIES] = {
	{ "quot", 4, DOUBLE_QUOTE },
	{ "amp", 3, '&' },
	{ "apos", 4, SINGLE_QUOTE },
	{ "lt", 2, '<' },
	{ "gt", 2, '>' }
};


StrPair::~StrPair() { Reset(); }


void StrPair::TransferTo(StrPair* other)
{
	if (this == other) { return; }
	// This in effect implements the assignment operator by "moving"
	// ownership (as in auto_ptr).

	TIXMLASSERT(other != nullptr);
	TIXMLASSERT(other->_flags == 0);
	TIXMLASSERT(other->_start == nullptr);
	TIXMLASSERT(other->_end == nullptr);

	other->Reset();

	other->_flags = _flags;
	other->_start = _start;
	other->_end   = _end;

	_flags = 0;
	_start = nullptr;
	_end   = nullptr;
}


void StrPair::Reset()
{
	if (_flags & NEEDS_DELETE) { delete[] _start; }
	_flags = 0;
	_start = nullptr;
	_end   = nullptr;
}


void StrPair::SetStr(const char* str, const int flags)
{
	TIXMLASSERT(str);
	Reset();
	const size_t len = strlen(str);
	TIXMLASSERT(_start == nullptr);
	_start = new char[len + 1];
	memcpy(_start, str, len + 1);
	_end   = _start + len;
	_flags = flags | NEEDS_DELETE;
}


char* StrPair::ParseText(char* in, const char* endTag, const int strFlags, int* curLineNumPtr)
{
	TIXMLASSERT(in);
	TIXMLASSERT(endTag && *endTag);
	TIXMLASSERT(curLineNumPtr);

	char* start         = in;
	const char endChar  = *endTag;
	const size_t length = strlen(endTag);

	// Inner loop of text parsing.
	while (*in)
	{
		if (*in == endChar && strncmp(in, endTag, length) == 0)
		{
			Set(start, in, strFlags);
			return in + length;
		}
		if (*in == '\n') { ++(*curLineNumPtr); }
		++in;
		TIXMLASSERT(in);
	}
	return nullptr;
}


char* StrPair::ParseName(char* in)
{
	if (!in || !(*in) || !XMLUtil::IsNameStartChar(*in)) { return nullptr; }

	char* const start = in;
	++in;
	while (*in && XMLUtil::IsNameChar(*in)) { ++in; }

	Set(start, in, 0);
	return in;
}


void StrPair::CollapseWhitespace()
{
	// Adjusting _start would cause undefined behavior on delete[]
	TIXMLASSERT((_flags & NEEDS_DELETE) == 0);
	// Trim leading space.
	_start = XMLUtil::SkipWhiteSpace(_start, nullptr);

	if (*_start)
	{
		const char* p = _start;	// the read pointer
		char* q       = _start;	// the write pointer

		while (*p)
		{
			if (XMLUtil::IsWhiteSpace(*p))
			{
				p = XMLUtil::SkipWhiteSpace(p, nullptr);
				if (*p == 0)
				{
					break;    // don't write to q; this trims the trailing space.
				}
				*q = ' ';
				++q;
			}
			*q = *p;
			++q;
			++p;
		}
		*q = 0;
	}
}


const char* StrPair::GetStr()
{
	TIXMLASSERT(_start);
	TIXMLASSERT(_end);
	if (_flags & NEEDS_FLUSH)
	{
		*_end = 0;
		_flags ^= NEEDS_FLUSH;

		if (_flags)
		{
			const char* p = _start;	// the read pointer
			char* q       = _start;	// the write pointer

			while (p < _end)
			{
				if ((_flags & NEEDS_NEWLINE_NORMALIZATION) && *p == CR)
				{
					// CR-LF pair becomes LF
					// CR alone becomes LF
					// LF-CR becomes LF
					if (*(p + 1) == LF) { p += 2; }
					else { ++p; }
					*q = LF;
					++q;
				}
				else if ((_flags & NEEDS_NEWLINE_NORMALIZATION) && *p == LF)
				{
					if (*(p + 1) == CR) { p += 2; }
					else { ++p; }
					*q = LF;
					++q;
				}
				else if ((_flags & NEEDS_ENTITY_PROCESSING) && *p == '&')
				{
					// Entities handled by tinyXML2:
					// - special entities in the entity table [in/out]
					// - numeric character reference [in]
					//   &#20013; or &#x4e2d;

					if (*(p + 1) == '#')
					{
						const int buflen = 10;
						char buf[buflen] = { 0 };
						int len          = 0;
						char* adjusted   = const_cast<char*>(XMLUtil::GetCharacterRef(p, buf, &len));
						if (adjusted == nullptr)
						{
							*q = *p;
							++p;
							++q;
						}
						else
						{
							TIXMLASSERT(0 <= len && len <= buflen);
							TIXMLASSERT(q + len <= adjusted);
							p = adjusted;
							memcpy(q, buf, len);
							q += len;
						}
					}
					else
					{
						bool entityFound = false;
						for (int i = 0; i < NUM_ENTITIES; ++i)
						{
							const Entity& entity = ENTITIES[i];
							if (strncmp(p + 1, entity.pattern, entity.length) == 0
								&& *(p + entity.length + 1) == ';')
							{
								// Found an entity - convert.
								*q = entity.value;
								++q;
								p += entity.length + 2;
								entityFound = true;
								break;
							}
						}
						if (!entityFound)
						{
							// fixme: treat as error?
							++p;
							++q;
						}
					}
				}
				else
				{
					*q = *p;
					++p;
					++q;
				}
			}
			*q = 0;
		}
		// The loop below has plenty going on, and this
		// is a less useful mode. Break it out.
		if (_flags & NEEDS_WHITESPACE_COLLAPSING) { CollapseWhitespace(); }
		_flags = (_flags & NEEDS_DELETE);
	}
	TIXMLASSERT(_start);
	return _start;
}


// --------- XMLUtil ----------- //

const char* XMLUtil::writeBoolTrue  = "true";
const char* XMLUtil::writeBoolFalse = "false";

void XMLUtil::SetBoolSerialization(const char* writeTrue, const char* writeFalse)
{
	static const char* defTrue  = "true";
	static const char* defFalse = "false";

	writeBoolTrue  = (writeTrue) ? writeTrue : defTrue;
	writeBoolFalse = (writeFalse) ? writeFalse : defFalse;
}


const char* XMLUtil::ReadBOM(const char* p, bool* bom)
{
	TIXMLASSERT(p);
	TIXMLASSERT(bom);
	*bom                    = false;
	const unsigned char* pu = reinterpret_cast<const unsigned char*>(p);
	// Check for BOM:
	if (*(pu + 0) == TIXML_UTF_LEAD_0
		&& *(pu + 1) == TIXML_UTF_LEAD_1
		&& *(pu + 2) == TIXML_UTF_LEAD_2)
	{
		*bom = true;
		p += 3;
	}
	TIXMLASSERT(p);
	return p;
}


void XMLUtil::ConvertUTF32ToUTF8(unsigned long input, char* output, int* length)
{
	const unsigned long BYTE_MASK          = 0xBF;
	const unsigned long BYTE_MARK          = 0x80;
	const unsigned long FIRST_BYTE_MARK[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };

	if (input < 0x80) { *length = 1; }
	else if (input < 0x800) { *length = 2; }
	else if (input < 0x10000) { *length = 3; }
	else if (input < 0x200000) { *length = 4; }
	else
	{
		*length = 0;    // This code won't convert this correctly anyway.
		return;
	}

	output += *length;

	// Scary scary fall throughs are annotated with carefully designed comments
	// to suppress compiler warnings such as -Wimplicit-fallthrough in gcc
	switch (*length)
	{
		case 4:
			--output;
			*output = char((input | BYTE_MARK) & BYTE_MASK);
			input >>= 6;
			//fall through
		case 3:
			--output;
			*output = char((input | BYTE_MARK) & BYTE_MASK);
			input >>= 6;
			//fall through
		case 2:
			--output;
			*output = char((input | BYTE_MARK) & BYTE_MASK);
			input >>= 6;
			//fall through
		case 1:
			--output;
			*output = char(input | FIRST_BYTE_MARK[*length]);
			break;
		default:
		TIXMLASSERT(false);
	}
}


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;
		unsigned mult               = 1;
		static const char SEMICOLON = ';';

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

			q = strchr(q, SEMICOLON);

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

			delta = q - p;
			--q;

			while (*q != 'x')
			{
				unsigned int digit;
				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 nullptr; }
				TIXMLASSERT(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 nullptr; }

			q = strchr(q, SEMICOLON);

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

			delta = q - p;
			--q;

			while (*q != '#')
			{
				if (*q >= '0' && *q <= '9')
				{
					const unsigned int digit = *q - '0';
					TIXMLASSERT(digit < 10);
					TIXMLASSERT(digit == 0 || mult <= UINT_MAX / digit);
					const unsigned int digitScaled = mult * digit;
					TIXMLASSERT(ucs <= ULONG_MAX - digitScaled);
					ucs += digitScaled;
				}
				else { return nullptr; }
				TIXMLASSERT(mult <= UINT_MAX / 10);
				mult *= 10;
				--q;
			}
		}
		// convert the UCS to UTF-8
		ConvertUTF32ToUTF8(ucs, value, length);
		return p + delta + 1;
	}
	return p + 1;
}


void XMLUtil::ToStr(const int value, char* buffer, const int size) { TIXML_SNPRINTF(buffer, size, "%d", value); }

void XMLUtil::ToStr(const unsigned value, char* buffer, const int size) { TIXML_SNPRINTF(buffer, size, "%u", value); }

void XMLUtil::ToStr(const bool value, char* buffer, const int size) { TIXML_SNPRINTF(buffer, size, "%s", value ? writeBoolTrue : writeBoolFalse); }

/*
	ToStr() of a number is a very tricky topic.
	https://github.com/leethomason/tinyxml2/issues/106
*/
void XMLUtil::ToStr(const float value, char* buffer, const int size) { TIXML_SNPRINTF(buffer, size, "%.8g", value); }


void XMLUtil::ToStr(const double value, char* buffer, const int size) { TIXML_SNPRINTF(buffer, size, "%.17g", value); }


void XMLUtil::ToStr(const int64_t value, char* buffer, const int size)
{
	// horrible syntax trick to make the compiler happy about %lld
	TIXML_SNPRINTF(buffer, size, "%lld", static_cast<long long>(value));
}


bool XMLUtil::ToInt(const char* str, int* value)
{
	if (TIXML_SSCANF(str, "%d", value) == 1) { return true; }
	return false;
}

bool XMLUtil::ToUnsigned(const char* str, unsigned* value)
{
	if (TIXML_SSCANF(str, "%u", value) == 1) { return true; }
	return false;
}

bool XMLUtil::ToBool(const char* str, bool* value)
{
	int ival = 0;
	if (ToInt(str, &ival))
	{
		*value = ival != 0;
		return true;
	}
	if (StringEqual(str, "true"))
	{
		*value = true;
		return true;
	}
	if (StringEqual(str, "false"))
	{
		*value = false;
		return true;
	}
	return false;
}


bool XMLUtil::ToFloat(const char* str, float* value)
{
	if (TIXML_SSCANF(str, "%f", value) == 1) { return true; }
	return false;
}


bool XMLUtil::ToDouble(const char* str, double* value)
{
	if (TIXML_SSCANF(str, "%lf", value) == 1) { return true; }
	return false;
}


bool XMLUtil::ToInt64(const char* str, int64_t* value)
{
	long long v = 0;	// horrible syntax trick to make the compiler happy about %lld
	if (TIXML_SSCANF(str, "%lld", &v) == 1)
	{
		*value = int64_t(v);
		return true;
	}
	return false;
}


char* XMLDocument::Identify(char* p, XMLNode** node)
{
	TIXMLASSERT(node);
	TIXMLASSERT(p);
	char* const start   = p;
	int const startLine = _parseCurLineNum;
	p                   = XMLUtil::SkipWhiteSpace(p, &_parseCurLineNum);
	if (!*p)
	{
		*node = nullptr;
		TIXMLASSERT(p);
		return p;
	}

	// These strings define the matching patterns:
	static const char* xmlHeader     = { "<?" };
	static const char* commentHeader = { "<!--" };
	static const char* cdataHeader   = { "<![CDATA[" };
	static const char* dtdHeader     = { "<!" };
	static const char* elementHeader = { "<" };	// and a header for everything else; check last.

	static const int xmlHeaderLen     = 2;
	static const int commentHeaderLen = 4;
	static const int cdataHeaderLen   = 9;
	static const int dtdHeaderLen     = 2;
	static const int elementHeaderLen = 1;

	TIXMLASSERT(sizeof(XMLComment) == sizeof(XMLUnknown));		// use same memory pool
	TIXMLASSERT(sizeof(XMLComment) == sizeof(XMLDeclaration));	// use same memory pool
	XMLNode* returnNode;
	if (XMLUtil::StringEqual(p, xmlHeader, xmlHeaderLen))
	{
		returnNode                = CreateUnlinkedNode<XMLDeclaration>(_commentPool);
		returnNode->_parseLineNum = _parseCurLineNum;
		p += xmlHeaderLen;
	}
	else if (XMLUtil::StringEqual(p, commentHeader, commentHeaderLen))
	{
		returnNode                = CreateUnlinkedNode<XMLComment>(_commentPool);
		returnNode->_parseLineNum = _parseCurLineNum;
		p += commentHeaderLen;
	}
	else if (XMLUtil::StringEqual(p, cdataHeader, cdataHeaderLen))
	{
		XMLText* text             = CreateUnlinkedNode<XMLText>(_textPool);
		returnNode                = text;
		returnNode->_parseLineNum = _parseCurLineNum;
		p += cdataHeaderLen;
		text->SetCData(true);
	}
	else if (XMLUtil::StringEqual(p, dtdHeader, dtdHeaderLen))
	{
		returnNode                = CreateUnlinkedNode<XMLUnknown>(_commentPool);
		returnNode->_parseLineNum = _parseCurLineNum;
		p += dtdHeaderLen;
	}
	else if (XMLUtil::StringEqual(p, elementHeader, elementHeaderLen))
	{
		returnNode                = CreateUnlinkedNode<XMLElement>(_elementPool);
		returnNode->_parseLineNum = _parseCurLineNum;
		p += elementHeaderLen;
	}
	else
	{
		returnNode                = CreateUnlinkedNode<XMLText>(_textPool);
		returnNode->_parseLineNum = _parseCurLineNum; // Report line of first non-whitespace character
		p                         = start;	// Back it up, all the text counts.
		_parseCurLineNum          = startLine;
	}

	TIXMLASSERT(returnNode);
	TIXMLASSERT(p);
	*node = returnNode;
	return p;
}


bool XMLDocument::Accept(XMLVisitor* visitor) const
{
	TIXMLASSERT(visitor);
	if (visitor->VisitEnter(*this)) { for (const XMLNode* node = FirstChild(); node; node = node->NextSibling()) { if (!node->Accept(visitor)) { break; } } }
	return visitor->VisitExit(*this);
}


// --------- XMLNode ----------- //

XMLNode::XMLNode(XMLDocument* doc) : _document(doc),
									 _memPool(nullptr) { }


XMLNode::~XMLNode()
{
	DeleteChildren();
	if (_parent) { _parent->Unlink(this); }
}

const char* XMLNode::Value() const
{
	// Edge case: XMLDocuments don't have a Value. Return null.
	if (this->ToDocument()) { return nullptr; }
	return _value.GetStr();
}

void XMLNode::SetValue(const char* val, const bool staticMem)
{
	if (staticMem) { _value.SetInternedStr(val); }
	else { _value.SetStr(val); }
}

XMLNode* XMLNode::DeepClone(XMLDocument* target) const
{
	XMLNode* clone = this->ShallowClone(target);
	if (!clone) { return nullptr; }

	for (const XMLNode* child = this->FirstChild(); child; child = child->NextSibling())
	{
		XMLNode* childClone = child->DeepClone(target);
		TIXMLASSERT(childClone);
		clone->InsertEndChild(childClone);
	}
	return clone;
}

void XMLNode::DeleteChildren()
{
	while (_firstChild)
	{
		TIXMLASSERT(_lastChild);
		DeleteChild(_firstChild);
	}
	_firstChild = _lastChild = nullptr;
}


void XMLNode::Unlink(XMLNode* child)
{
	TIXMLASSERT(child);
	TIXMLASSERT(child->_document == _document);
	TIXMLASSERT(child->_parent == this);
	if (child == _firstChild) { _firstChild = _firstChild->_next; }
	if (child == _lastChild) { _lastChild = _lastChild->_prev; }

	if (child->_prev) { child->_prev->_next = child->_next; }
	if (child->_next) { child->_next->_prev = child->_prev; }
	child->_next   = nullptr;
	child->_prev   = nullptr;
	child->_parent = nullptr;
}


void XMLNode::DeleteChild(XMLNode* node)
{
	TIXMLASSERT(node);
	TIXMLASSERT(node->_document == _document);
	TIXMLASSERT(node->_parent == this);
	Unlink(node);
	TIXMLASSERT(node->_prev == nullptr);
	TIXMLASSERT(node->_next == nullptr);
	TIXMLASSERT(node->_parent == nullptr);
	DeleteNode(node);
}


XMLNode* XMLNode::InsertEndChild(XMLNode* addThis)
{
	TIXMLASSERT(addThis);
	if (addThis->_document != _document)
	{
		TIXMLASSERT(false);
		return nullptr;
	}
	InsertChildPreamble(addThis);

	if (_lastChild)
	{
		TIXMLASSERT(_firstChild);
		TIXMLASSERT(_lastChild->_next == nullptr);
		_lastChild->_next = addThis;
		addThis->_prev    = _lastChild;
		_lastChild        = addThis;

		addThis->_next = nullptr;
	}
	else
	{
		TIXMLASSERT(_firstChild == nullptr);
		_firstChild = _lastChild = addThis;

		addThis->_prev = nullptr;
		addThis->_next = nullptr;
	}
	addThis->_parent = this;
	return addThis;
}


XMLNode* XMLNode::InsertFirstChild(XMLNode* addThis)
{
	TIXMLASSERT(addThis);
	if (addThis->_document != _document)
	{
		TIXMLASSERT(false);
		return nullptr;
	}
	InsertChildPreamble(addThis);

	if (_firstChild)
	{
		TIXMLASSERT(_lastChild);
		TIXMLASSERT(_firstChild->_prev == nullptr);

		_firstChild->_prev = addThis;
		addThis->_next     = _firstChild;
		_firstChild        = addThis;

		addThis->_prev = nullptr;
	}
	else
	{
		TIXMLASSERT(_lastChild == nullptr);
		_firstChild = _lastChild = addThis;

		addThis->_prev = nullptr;
		addThis->_next = nullptr;
	}
	addThis->_parent = this;
	return addThis;
}


XMLNode* XMLNode::InsertAfterChild(XMLNode* afterThis, XMLNode* addThis)
{
	TIXMLASSERT(addThis);
	if (addThis->_document != _document)
	{
		TIXMLASSERT(false);
		return nullptr;
	}

	TIXMLASSERT(afterThis);

	if (afterThis->_parent != this)
	{
		TIXMLASSERT(false);
		return nullptr;
	}
	if (afterThis == addThis)
	{
		// Current state: BeforeThis -> AddThis -> OneAfterAddThis
		// Now AddThis must disappear from it's location and then
		// reappear between BeforeThis and OneAfterAddThis.
		// So just leave it where it is.
		return addThis;
	}

	if (afterThis->_next == nullptr)
	{
		// The last node or the only node.
		return InsertEndChild(addThis);
	}
	InsertChildPreamble(addThis);
	addThis->_prev          = afterThis;
	addThis->_next          = afterThis->_next;
	afterThis->_next->_prev = addThis;
	afterThis->_next        = addThis;
	addThis->_parent        = this;
	return addThis;
}


const XMLElement* XMLNode::FirstChildElement(const char* name) const
{
	for (const XMLNode* node = _firstChild; node; node = node->_next)
	{
		const XMLElement* element = node->ToElementWithName(name);
		if (element) { return element; }
	}
	return nullptr;
}


const XMLElement* XMLNode::LastChildElement(const char* name) const
{
	for (const XMLNode* node = _lastChild; node; node = node->_prev)
	{
		const XMLElement* element = node->ToElementWithName(name);
		if (element) { return element; }
	}
	return nullptr;
}


const XMLElement* XMLNode::NextSiblingElement(const char* name) const
{
	for (const XMLNode* node = _next; node; node = node->_next)
	{
		const XMLElement* element = node->ToElementWithName(name);
		if (element) { return element; }
	}
	return nullptr;
}


const XMLElement* XMLNode::PreviousSiblingElement(const char* name) const
{
	for (const XMLNode* node = _prev; node; node = node->_prev)
	{
		const XMLElement* element = node->ToElementWithName(name);
		if (element) { return element; }
	}
	return nullptr;
}


char* XMLNode::ParseDeep(char* p, StrPair* parentEndTag, int* curLineNumPtr)
{
	// This is a recursive method, but thinking about it "at the current level"
	// it is a pretty simple flat list:
	//		<foo/>
	//		<!-- comment -->
	//
	// With a special case:
	//		<foo>
	//		</foo>
	//		<!-- comment -->
	//
	// Where the closing element (/foo) *must* be the next thing after the opening
	// element, and the names must match. BUT the tricky bit is that the closing
	// element will be read by the child.
	//
	// 'endTag' is the end tag for this node, it is returned by a call to a child.
	// 'parentEnd' is the end tag for the parent, which is filled in and returned.

	XMLDocument::DepthTracker tracker(_document);
	if (_document->Error()) { return nullptr; }

	while (p && *p)
	{
		XMLNode* node = nullptr;

		p = _document->Identify(p, &node);
		TIXMLASSERT(p);
		if (node == nullptr) { break; }

		const int initialLineNum = node->_parseLineNum;

		StrPair endTag;
		p = node->ParseDeep(p, &endTag, curLineNumPtr);
		if (!p)
		{
			DeleteNode(node);
			if (!_document->Error()) { _document->SetError(XML_ERROR_PARSING, initialLineNum, nullptr); }
			break;
		}

		XMLDeclaration* decl = node->ToDeclaration();
		if (decl)
		{
			// Declarations are only allowed at document level
			//
			// Multiple declarations are allowed but all declarations
			// must occur before anything else. 
			//
			// Optimized due to a security test case. If the first node is 
			// a declaration, and the last node is a declaration, then only 
			// declarations have so far been addded.
			bool wellLocated = false;

			if (ToDocument())
			{
				if (FirstChild()) { wellLocated = FirstChild() && FirstChild()->ToDeclaration() && LastChild() && LastChild()->ToDeclaration(); }
				else { wellLocated = true; }
			}
			if (!wellLocated)
			{
				_document->SetError(XML_ERROR_PARSING_DECLARATION, initialLineNum, "XMLDeclaration value=%s", decl->Value());
				DeleteNode(node);
				break;
			}
		}

		XMLElement* ele = node->ToElement();
		if (ele)
		{
			// We read the end tag. Return it to the parent.
			if (ele->ClosingType() == XMLElement::CLOSING)
			{
				if (parentEndTag) { ele->_value.TransferTo(parentEndTag); }
				node->_memPool->SetTracked();   // created and then immediately deleted.
				DeleteNode(node);
				return p;
			}

			// Handle an end tag returned to this level.
			// And handle a bunch of annoying errors.
			bool mismatch = false;
			if (endTag.Empty()) { if (ele->ClosingType() == XMLElement::OPEN) { mismatch = true; } }
			else
			{
				if (ele->ClosingType() != XMLElement::OPEN) { mismatch = true; }
				else if (!XMLUtil::StringEqual(endTag.GetStr(), ele->Name())) { mismatch = true; }
			}
			if (mismatch)
			{
				_document->SetError(XML_ERROR_MISMATCHED_ELEMENT, initialLineNum, "XMLElement name=%s", ele->Name());
				DeleteNode(node);
				break;
			}
		}
		InsertEndChild(node);
	}
	return nullptr;
}

/*static*/
void XMLNode::DeleteNode(XMLNode* node)
{
	if (node == nullptr) { return; }
	TIXMLASSERT(node->_document);
	if (!node->ToDocument()) { node->_document->MarkInUse(node); }

	MemPool* pool = node->_memPool;
	node->~XMLNode();
	pool->Free(node);
}

void XMLNode::InsertChildPreamble(XMLNode* insertThis) const
{
	TIXMLASSERT(insertThis);
	TIXMLASSERT(insertThis->_document == _document);

	if (insertThis->_parent) { insertThis->_parent->Unlink(insertThis); }
	else
	{
		insertThis->_document->MarkInUse(insertThis);
		insertThis->_memPool->SetTracked();
	}
}

const XMLElement* XMLNode::ToElementWithName(const char* name) const
{
	const XMLElement* element = this->ToElement();
	if (element == nullptr) { return nullptr; }
	if (name == nullptr) { return element; }
	if (XMLUtil::StringEqual(element->Name(), name)) { return element; }
	return nullptr;
}

// --------- XMLText ---------- //
char* XMLText::ParseDeep(char* p, StrPair* /*parentEndTag*/, int* curLineNumPtr)
{
	if (this->CData())
	{
		p = _value.ParseText(p, "]]>", StrPair::NEEDS_NEWLINE_NORMALIZATION, curLineNumPtr);
		if (!p) { _document->SetError(XML_ERROR_PARSING_CDATA, _parseLineNum, nullptr); }
		return p;
	}
	int flags = _document->ProcessEntities() ? StrPair::TEXT_ELEMENT : StrPair::TEXT_ELEMENT_LEAVE_ENTITIES;
	if (_document->WhitespaceMode() == COLLAPSE_WHITESPACE) { flags |= StrPair::NEEDS_WHITESPACE_COLLAPSING; }

	p = _value.ParseText(p, "<", flags, curLineNumPtr);
	if (p && *p) { return p - 1; }
	if (!p) { _document->SetError(XML_ERROR_PARSING_TEXT, _parseLineNum, nullptr); }
	return nullptr;
}


XMLNode* XMLText::ShallowClone(XMLDocument* doc) const
{
	if (!doc) { doc = _document; }
	XMLText* text = doc->NewText(Value());	// fixme: this will always allocate memory. Intern?
	text->SetCData(this->CData());
	return text;
}


bool XMLText::ShallowEqual(const XMLNode* compare) const
{
	TIXMLASSERT(compare);
	const XMLText* text = compare->ToText();
	return (text && XMLUtil::StringEqual(text->Value(), Value()));
}


bool XMLText::Accept(XMLVisitor* visitor) const
{
	TIXMLASSERT(visitor);
	return visitor->Visit(*this);
}


// --------- XMLComment ---------- //

char* XMLComment::ParseDeep(char* p, StrPair* /*parentEndTag*/, int* curLineNumPtr)
{
	// Comment parses as text.
	p = _value.ParseText(p, "-->", StrPair::COMMENT, curLineNumPtr);
	if (p == nullptr) { _document->SetError(XML_ERROR_PARSING_COMMENT, _parseLineNum, nullptr); }
	return p;
}


XMLNode* XMLComment::ShallowClone(XMLDocument* doc) const
{
	if (!doc) { doc = _document; }
	XMLComment* comment = doc->NewComment(Value());	// fixme: this will always allocate memory. Intern?
	return comment;
}


bool XMLComment::ShallowEqual(const XMLNode* compare) const
{
	TIXMLASSERT(compare);
	const XMLComment* comment = compare->ToComment();
	return (comment && XMLUtil::StringEqual(comment->Value(), Value()));
}


bool XMLComment::Accept(XMLVisitor* visitor) const
{
	TIXMLASSERT(visitor);
	return visitor->Visit(*this);
}


// --------- XMLDeclaration ---------- //

char* XMLDeclaration::ParseDeep(char* p, StrPair* /*parentEndTag*/, int* curLineNumPtr)
{
	// Declaration parses as text.
	p = _value.ParseText(p, "?>", StrPair::NEEDS_NEWLINE_NORMALIZATION, curLineNumPtr);
	if (p == nullptr) { _document->SetError(XML_ERROR_PARSING_DECLARATION, _parseLineNum, nullptr); }
	return p;
}


XMLNode* XMLDeclaration::ShallowClone(XMLDocument* doc) const
{
	if (!doc) { doc = _document; }
	XMLDeclaration* dec = doc->NewDeclaration(Value());	// fixme: this will always allocate memory. Intern?
	return dec;
}


bool XMLDeclaration::ShallowEqual(const XMLNode* compare) const
{
	TIXMLASSERT(compare);
	const XMLDeclaration* declaration = compare->ToDeclaration();
	return (declaration && XMLUtil::StringEqual(declaration->Value(), Value()));
}


bool XMLDeclaration::Accept(XMLVisitor* visitor) const
{
	TIXMLASSERT(visitor);
	return visitor->Visit(*this);
}

// --------- XMLUnknown ---------- //

char* XMLUnknown::ParseDeep(char* p, StrPair* /*parentEndTag*/, int* curLineNumPtr)
{
	// Unknown parses as text.
	p = _value.ParseText(p, ">", StrPair::NEEDS_NEWLINE_NORMALIZATION, curLineNumPtr);
	if (!p) { _document->SetError(XML_ERROR_PARSING_UNKNOWN, _parseLineNum, nullptr); }
	return p;
}


XMLNode* XMLUnknown::ShallowClone(XMLDocument* doc) const
{
	if (!doc) { doc = _document; }
	XMLUnknown* text = doc->NewUnknown(Value());	// fixme: this will always allocate memory. Intern?
	return text;
}


bool XMLUnknown::ShallowEqual(const XMLNode* compare) const
{
	TIXMLASSERT(compare);
	const XMLUnknown* unknown = compare->ToUnknown();
	return (unknown && XMLUtil::StringEqual(unknown->Value(), Value()));
}


bool XMLUnknown::Accept(XMLVisitor* visitor) const
{
	TIXMLASSERT(visitor);
	return visitor->Visit(*this);
}

// --------- XMLAttribute ---------- //

char* XMLAttribute::ParseDeep(char* p, const bool processEntities, int* curLineNumPtr)
{
	// Parse using the name rules: bug fix, was using ParseText before
	p = _name.ParseName(p);
	if (!p || !*p) { return nullptr; }

	// Skip white space before =
	p = XMLUtil::SkipWhiteSpace(p, curLineNumPtr);
	if (*p != '=') { return nullptr; }

	++p;	// move up to opening quote
	p = XMLUtil::SkipWhiteSpace(p, curLineNumPtr);
	if (*p != '\"' && *p != '\'') { return nullptr; }

	char endTag[2] = { *p, 0 };
	++p;	// move past opening quote

	p = _value.ParseText(p, endTag, processEntities ? StrPair::ATTRIBUTE_VALUE : StrPair::ATTRIBUTE_VALUE_LEAVE_ENTITIES, curLineNumPtr);
	return p;
}


XMLError XMLAttribute::QueryIntValue(int* value) const
{
	if (XMLUtil::ToInt(Value(), value)) { return XML_SUCCESS; }
	return XML_WRONG_ATTRIBUTE_TYPE;
}


XMLError XMLAttribute::QueryUnsignedValue(unsigned int* value) const
{
	if (XMLUtil::ToUnsigned(Value(), value)) { return XML_SUCCESS; }
	return XML_WRONG_ATTRIBUTE_TYPE;
}


XMLError XMLAttribute::QueryInt64Value(int64_t* value) const
{
	if (XMLUtil::ToInt64(Value(), value)) { return XML_SUCCESS; }
	return XML_WRONG_ATTRIBUTE_TYPE;
}


XMLError XMLAttribute::QueryBoolValue(bool* value) const
{
	if (XMLUtil::ToBool(Value(), value)) { return XML_SUCCESS; }
	return XML_WRONG_ATTRIBUTE_TYPE;
}


XMLError XMLAttribute::QueryFloatValue(float* value) const
{
	if (XMLUtil::ToFloat(Value(), value)) { return XML_SUCCESS; }
	return XML_WRONG_ATTRIBUTE_TYPE;
}


XMLError XMLAttribute::QueryDoubleValue(double* value) const
{
	if (XMLUtil::ToDouble(Value(), value)) { return XML_SUCCESS; }
	return XML_WRONG_ATTRIBUTE_TYPE;
}

void XMLAttribute::SetAttribute(const int value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	_value.SetStr(buf);
}


void XMLAttribute::SetAttribute(const unsigned value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	_value.SetStr(buf);
}


void XMLAttribute::SetAttribute(const int64_t value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	_value.SetStr(buf);
}


void XMLAttribute::SetAttribute(const bool value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	_value.SetStr(buf);
}

void XMLAttribute::SetAttribute(const double value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	_value.SetStr(buf);
}

void XMLAttribute::SetAttribute(const float value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	_value.SetStr(buf);
}


// --------- XMLElement ---------- //

XMLElement::~XMLElement()
{
	while (_rootAttribute)
	{
		XMLAttribute* next = _rootAttribute->_next;
		DeleteAttribute(_rootAttribute);
		_rootAttribute = next;
	}
}


const XMLAttribute* XMLElement::FindAttribute(const char* name) const
{
	for (XMLAttribute* a = _rootAttribute; a; a = a->_next) { if (XMLUtil::StringEqual(a->Name(), name)) { return a; } }
	return nullptr;
}


const char* XMLElement::Attribute(const char* name, const char* value) const
{
	const XMLAttribute* a = FindAttribute(name);
	if (!a) { return nullptr; }
	if (!value || XMLUtil::StringEqual(a->Value(), value)) { return a->Value(); }
	return nullptr;
}

int XMLElement::IntAttribute(const char* name, const int defaultValue) const
{
	int i = defaultValue;
	QueryIntAttribute(name, &i);
	return i;
}

unsigned XMLElement::UnsignedAttribute(const char* name, const unsigned defaultValue) const
{
	unsigned i = defaultValue;
	QueryUnsignedAttribute(name, &i);
	return i;
}

int64_t XMLElement::Int64Attribute(const char* name, const int64_t defaultValue) const
{
	int64_t i = defaultValue;
	QueryInt64Attribute(name, &i);
	return i;
}

bool XMLElement::BoolAttribute(const char* name, const bool defaultValue) const
{
	bool b = defaultValue;
	QueryBoolAttribute(name, &b);
	return b;
}

double XMLElement::DoubleAttribute(const char* name, const double defaultValue) const
{
	double d = defaultValue;
	QueryDoubleAttribute(name, &d);
	return d;
}

float XMLElement::FloatAttribute(const char* name, const float defaultValue) const
{
	float f = defaultValue;
	QueryFloatAttribute(name, &f);
	return f;
}

const char* XMLElement::GetText() const
{
	if (FirstChild() && FirstChild()->ToText()) { return FirstChild()->Value(); }
	return nullptr;
}


void XMLElement::SetText(const char* inText)
{
	if (FirstChild() && FirstChild()->ToText()) { FirstChild()->SetValue(inText); }
	else
	{
		XMLText* theText = GetDocument()->NewText(inText);
		InsertFirstChild(theText);
	}
}


void XMLElement::SetText(const int value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	SetText(buf);
}


void XMLElement::SetText(const unsigned value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	SetText(buf);
}


void XMLElement::SetText(const int64_t value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	SetText(buf);
}


void XMLElement::SetText(const bool value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	SetText(buf);
}


void XMLElement::SetText(const float value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	SetText(buf);
}


void XMLElement::SetText(const double value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	SetText(buf);
}


XMLError XMLElement::QueryIntText(int* val) const
{
	if (FirstChild() && FirstChild()->ToText())
	{
		const char* t = FirstChild()->Value();
		if (XMLUtil::ToInt(t, val)) { return XML_SUCCESS; }
		return XML_CAN_NOT_CONVERT_TEXT;
	}
	return XML_NO_TEXT_NODE;
}


XMLError XMLElement::QueryUnsignedText(unsigned* val) const
{
	if (FirstChild() && FirstChild()->ToText())
	{
		const char* t = FirstChild()->Value();
		if (XMLUtil::ToUnsigned(t, val)) { return XML_SUCCESS; }
		return XML_CAN_NOT_CONVERT_TEXT;
	}
	return XML_NO_TEXT_NODE;
}


XMLError XMLElement::QueryInt64Text(int64_t* val) const
{
	if (FirstChild() && FirstChild()->ToText())
	{
		const char* t = FirstChild()->Value();
		if (XMLUtil::ToInt64(t, val)) { return XML_SUCCESS; }
		return XML_CAN_NOT_CONVERT_TEXT;
	}
	return XML_NO_TEXT_NODE;
}


XMLError XMLElement::QueryBoolText(bool* val) const
{
	if (FirstChild() && FirstChild()->ToText())
	{
		const char* t = FirstChild()->Value();
		if (XMLUtil::ToBool(t, val)) { return XML_SUCCESS; }
		return XML_CAN_NOT_CONVERT_TEXT;
	}
	return XML_NO_TEXT_NODE;
}


XMLError XMLElement::QueryDoubleText(double* val) const
{
	if (FirstChild() && FirstChild()->ToText())
	{
		const char* t = FirstChild()->Value();
		if (XMLUtil::ToDouble(t, val)) { return XML_SUCCESS; }
		return XML_CAN_NOT_CONVERT_TEXT;
	}
	return XML_NO_TEXT_NODE;
}


XMLError XMLElement::QueryFloatText(float* val) const
{
	if (FirstChild() && FirstChild()->ToText())
	{
		const char* t = FirstChild()->Value();
		if (XMLUtil::ToFloat(t, val)) { return XML_SUCCESS; }
		return XML_CAN_NOT_CONVERT_TEXT;
	}
	return XML_NO_TEXT_NODE;
}

int XMLElement::IntText(const int defaultValue) const
{
	int i = defaultValue;
	QueryIntText(&i);
	return i;
}

unsigned XMLElement::UnsignedText(const unsigned defaultValue) const
{
	unsigned i = defaultValue;
	QueryUnsignedText(&i);
	return i;
}

int64_t XMLElement::Int64Text(const int64_t defaultValue) const
{
	int64_t i = defaultValue;
	QueryInt64Text(&i);
	return i;
}

bool XMLElement::BoolText(const bool defaultValue) const
{
	bool b = defaultValue;
	QueryBoolText(&b);
	return b;
}

double XMLElement::DoubleText(const double defaultValue) const
{
	double d = defaultValue;
	QueryDoubleText(&d);
	return d;
}

float XMLElement::FloatText(const float defaultValue) const
{
	float f = defaultValue;
	QueryFloatText(&f);
	return f;
}


XMLAttribute* XMLElement::FindOrCreateAttribute(const char* name)
{
	XMLAttribute* last   = nullptr;
	XMLAttribute* attrib = _rootAttribute;
	for (; attrib; last = attrib, attrib = attrib->_next) { if (XMLUtil::StringEqual(attrib->Name(), name)) { break; } }
	if (!attrib)
	{
		attrib = CreateAttribute();
		TIXMLASSERT(attrib);
		if (last)
		{
			TIXMLASSERT(last->_next == nullptr);
			last->_next = attrib;
		}
		else
		{
			TIXMLASSERT(_rootAttribute == nullptr);
			_rootAttribute = attrib;
		}
		attrib->SetName(name);
	}
	return attrib;
}


void XMLElement::DeleteAttribute(const char* name)
{
	XMLAttribute* prev = nullptr;
	for (XMLAttribute* a = _rootAttribute; a; a = a->_next)
	{
		if (XMLUtil::StringEqual(name, a->Name()))
		{
			if (prev) { prev->_next = a->_next; }
			else { _rootAttribute = a->_next; }
			DeleteAttribute(a);
			break;
		}
		prev = a;
	}
}


char* XMLElement::ParseAttributes(char* p, int* curLineNumPtr)
{
	XMLAttribute* prevAttribute = nullptr;

	// Read the attributes.
	while (p)
	{
		p = XMLUtil::SkipWhiteSpace(p, curLineNumPtr);
		if (!(*p))
		{
			_document->SetError(XML_ERROR_PARSING_ELEMENT, _parseLineNum, "XMLElement name=%s", Name());
			return nullptr;
		}

		// attribute.
		if (XMLUtil::IsNameStartChar(*p))
		{
			XMLAttribute* attrib = CreateAttribute();
			TIXMLASSERT(attrib);
			attrib->_parseLineNum = _document->_parseCurLineNum;

			const int attrLineNum = attrib->_parseLineNum;

			p = attrib->ParseDeep(p, _document->ProcessEntities(), curLineNumPtr);
			if (!p || Attribute(attrib->Name()))
			{
				DeleteAttribute(attrib);
				_document->SetError(XML_ERROR_PARSING_ATTRIBUTE, attrLineNum, "XMLElement name=%s", Name());
				return nullptr;
			}
			// There is a minor bug here: if the attribute in the source xml
			// document is duplicated, it will not be detected and the
			// attribute will be doubly added. However, tracking the 'prevAttribute'
			// avoids re-scanning the attribute list. Preferring performance for
			// now, may reconsider in the future.
			if (prevAttribute)
			{
				TIXMLASSERT(prevAttribute->_next == nullptr);
				prevAttribute->_next = attrib;
			}
			else
			{
				TIXMLASSERT(_rootAttribute == nullptr);
				_rootAttribute = attrib;
			}
			prevAttribute = attrib;
		}
			// end of the tag
		else if (*p == '>')
		{
			++p;
			break;
		}
			// end of the tag
		else if (*p == '/' && *(p + 1) == '>')
		{
			_closingType = CLOSED;
			return p + 2;	// done; sealed element.
		}
		else
		{
			_document->SetError(XML_ERROR_PARSING_ELEMENT, _parseLineNum, nullptr);
			return nullptr;
		}
	}
	return p;
}

void XMLElement::DeleteAttribute(XMLAttribute* attribute)
{
	if (attribute == nullptr) { return; }
	MemPool* pool = attribute->_memPool;
	attribute->~XMLAttribute();
	pool->Free(attribute);
}

XMLAttribute* XMLElement::CreateAttribute()
{
	TIXMLASSERT(sizeof(XMLAttribute) == _document->_attributePool.ItemSize());
	XMLAttribute* attrib = new(_document->_attributePool.Alloc()) XMLAttribute();
	TIXMLASSERT(attrib);
	attrib->_memPool = &_document->_attributePool;
	attrib->_memPool->SetTracked();
	return attrib;
}

//
//	<ele></ele>
//	<ele>foo<b>bar</b></ele>
//
char* XMLElement::ParseDeep(char* p, StrPair* parentEndTag, int* curLineNumPtr)
{
	// Read the element name.
	p = XMLUtil::SkipWhiteSpace(p, curLineNumPtr);

	// The closing element is the </element> form. It is
	// parsed just like a regular element then deleted from
	// the DOM.
	if (*p == '/')
	{
		_closingType = CLOSING;
		++p;
	}

	p = _value.ParseName(p);
	if (_value.Empty()) { return nullptr; }

	p = ParseAttributes(p, curLineNumPtr);
	if (!p || !*p || _closingType != OPEN) { return p; }

	p = XMLNode::ParseDeep(p, parentEndTag, curLineNumPtr);
	return p;
}


XMLNode* XMLElement::ShallowClone(XMLDocument* doc) const
{
	if (!doc) { doc = _document; }
	XMLElement* element = doc->NewElement(Value());					// fixme: this will always allocate memory. Intern?
	for (const XMLAttribute* a = FirstAttribute(); a; a = a->Next())
	{
		element->SetAttribute(a->Name(), a->Value());					// fixme: this will always allocate memory. Intern?
	}
	return element;
}


bool XMLElement::ShallowEqual(const XMLNode* compare) const
{
	TIXMLASSERT(compare);
	const XMLElement* other = compare->ToElement();
	if (other && XMLUtil::StringEqual(other->Name(), Name()))
	{
		const XMLAttribute* a = FirstAttribute();
		const XMLAttribute* b = other->FirstAttribute();

		while (a && b)
		{
			if (!XMLUtil::StringEqual(a->Value(), b->Value())) { return false; }
			a = a->Next();
			b = b->Next();
		}
		return !(a || b);  	// different count
	}
	return false;
}


bool XMLElement::Accept(XMLVisitor* visitor) const
{
	TIXMLASSERT(visitor);
	if (visitor->VisitEnter(*this, _rootAttribute))
	{
		for (const XMLNode* node = FirstChild(); node; node = node->NextSibling()) { if (!node->Accept(visitor)) { break; } }
	}
	return visitor->VisitExit(*this);
}


// --------- XMLDocument ----------- //

// Warning: List must match 'enum XMLError'
const char* XMLDocument::_errorNames[XML_ERROR_COUNT] = {
	"XML_SUCCESS",
	"XML_NO_ATTRIBUTE",
	"XML_WRONG_ATTRIBUTE_TYPE",
	"XML_ERROR_FILE_NOT_FOUND",
	"XML_ERROR_FILE_COULD_NOT_BE_OPENED",
	"XML_ERROR_FILE_READ_ERROR",
	"XML_ERROR_PARSING_ELEMENT",
	"XML_ERROR_PARSING_ATTRIBUTE",
	"XML_ERROR_PARSING_TEXT",
	"XML_ERROR_PARSING_CDATA",
	"XML_ERROR_PARSING_COMMENT",
	"XML_ERROR_PARSING_DECLARATION",
	"XML_ERROR_PARSING_UNKNOWN",
	"XML_ERROR_EMPTY_DOCUMENT",
	"XML_ERROR_MISMATCHED_ELEMENT",
	"XML_ERROR_PARSING",
	"XML_CAN_NOT_CONVERT_TEXT",
	"XML_NO_TEXT_NODE",
	"XML_ELEMENT_DEPTH_EXCEEDED"
};


XMLDocument::XMLDocument(bool processEntities, Whitespace whitespaceMode) : XMLNode(nullptr), _processEntities(processEntities),
																			_whitespaceMode(whitespaceMode)
{
	// avoid VC++ C4355 warning about 'this' in initializer list (C4355 is off by default in VS2012+)
	_document = this;
}


XMLDocument::~XMLDocument() { Clear(); }


void XMLDocument::MarkInUse(XMLNode* node)
{
	TIXMLASSERT(node);
	TIXMLASSERT(node->_parent == nullptr);

	for (int i = 0; i < _unlinked.Size(); ++i)
	{
		if (node == _unlinked[i])
		{
			_unlinked.SwapRemove(i);
			break;
		}
	}
}

void XMLDocument::Clear()
{
	DeleteChildren();
	while (_unlinked.Size()) { DeleteNode(_unlinked[0]); } // Will remove from _unlinked as part of delete.

#ifdef TINYXML2_DEBUG
	const bool hadError = Error();
#endif
	ClearError();

	delete[] _charBuffer;
	_charBuffer   = nullptr;
	_parsingDepth = 0;

#if 0
		_textPool.Trace("text");
		_elementPool.Trace("element");
		_commentPool.Trace("comment");
		_attributePool.Trace("attribute");
#endif

#ifdef TINYXML2_DEBUG
	if (!hadError)
	{
		TIXMLASSERT(_elementPool.CurrentAllocs() == _elementPool.Untracked());
		TIXMLASSERT(_attributePool.CurrentAllocs() == _attributePool.Untracked());
		TIXMLASSERT(_textPool.CurrentAllocs() == _textPool.Untracked());
		TIXMLASSERT(_commentPool.CurrentAllocs() == _commentPool.Untracked());
	}
#endif
}


void XMLDocument::DeepCopy(XMLDocument* target) const
{
	TIXMLASSERT(target);
	if (target == this) { return; } // technically success - a no-op.

	target->Clear();
	for (const XMLNode* node = this->FirstChild(); node; node = node->NextSibling()) { target->InsertEndChild(node->DeepClone(target)); }
}

XMLElement* XMLDocument::NewElement(const char* name)
{
	XMLElement* ele = CreateUnlinkedNode<XMLElement>(_elementPool);
	ele->SetName(name);
	return ele;
}


XMLComment* XMLDocument::NewComment(const char* str)
{
	XMLComment* comment = CreateUnlinkedNode<XMLComment>(_commentPool);
	comment->SetValue(str);
	return comment;
}


XMLText* XMLDocument::NewText(const char* str)
{
	XMLText* text = CreateUnlinkedNode<XMLText>(_textPool);
	text->SetValue(str);
	return text;
}


XMLDeclaration* XMLDocument::NewDeclaration(const char* str)
{
	XMLDeclaration* dec = CreateUnlinkedNode<XMLDeclaration>(_commentPool);
	dec->SetValue(str ? str : "xml version=\"1.0\" encoding=\"UTF-8\"");
	return dec;
}


XMLUnknown* XMLDocument::NewUnknown(const char* str)
{
	XMLUnknown* unk = CreateUnlinkedNode<XMLUnknown>(_commentPool);
	unk->SetValue(str);
	return unk;
}

static FILE* callfopen(const char* filepath, const char* mode)
{
	TIXMLASSERT(filepath);
	TIXMLASSERT(mode);
#if defined(_MSC_VER) && (_MSC_VER >= 1400 ) && (!defined WINCE)
	FILE* fp          = nullptr;
	const errno_t err = fopen_s(&fp, filepath, mode);
	if (err) { return nullptr; }
#else
		FILE* fp = fopen(filepath, mode);
#endif
	return fp;
}

void XMLDocument::DeleteNode(XMLNode* node)
{
	TIXMLASSERT(node);
	TIXMLASSERT(node->_document == this);
	if (node->_parent) { node->_parent->DeleteChild(node); }
	else
	{
		// Isn't in the tree.
		// Use the parent delete.
		// Also, we need to mark it tracked: we 'know'
		// it was never used.
		node->_memPool->SetTracked();
		// Call the static XMLNode version:
		XMLNode::DeleteNode(node);
	}
}


XMLError XMLDocument::LoadFile(const char* filename)
{
	if (!filename)
	{
		TIXMLASSERT(false);
		SetError(XML_ERROR_FILE_COULD_NOT_BE_OPENED, 0, "filename=<null>");
		return _errorID;
	}

	Clear();
	FILE* fp = callfopen(filename, "rb");
	if (!fp)
	{
		SetError(XML_ERROR_FILE_NOT_FOUND, 0, "filename=%s", filename);
		return _errorID;
	}
	LoadFile(fp);
	fclose(fp);
	return _errorID;
}

// This is likely overengineered template art to have a check that unsigned long value incremented
// by one still fits into size_t. If size_t type is larger than unsigned long type
// (x86_64-w64-mingw32 target) then the check is redundant and gcc and clang emit
// -Wtype-limits warning. This piece makes the compiler select code with a check when a check
// is useful and code with no check when a check is redundant depending on how size_t and unsigned long
// types sizes relate to each other.
template
<bool = (sizeof(unsigned long) >= sizeof(size_t))>
struct LongFitsIntoSizeTMinusOne
{
	static bool Fits(const unsigned long value) { return value < size_t(-1); }
};

template <>
struct LongFitsIntoSizeTMinusOne<false>
{
	static bool Fits(unsigned long /*value*/) { return true; }
};

XMLError XMLDocument::LoadFile(FILE* fp)
{
	Clear();

	fseek(fp, 0, SEEK_SET);
	if (fgetc(fp) == EOF && ferror(fp) != 0)
	{
		SetError(XML_ERROR_FILE_READ_ERROR, 0, nullptr);
		return _errorID;
	}

	fseek(fp, 0, SEEK_END);
	const long filelength = ftell(fp);
	fseek(fp, 0, SEEK_SET);
	if (filelength == -1L)
	{
		SetError(XML_ERROR_FILE_READ_ERROR, 0, nullptr);
		return _errorID;
	}
	TIXMLASSERT(filelength >= 0);

	if (!LongFitsIntoSizeTMinusOne<>::Fits(filelength))
	{
		// Cannot handle files which won't fit in buffer together with null terminator
		SetError(XML_ERROR_FILE_READ_ERROR, 0, nullptr);
		return _errorID;
	}

	if (filelength == 0)
	{
		SetError(XML_ERROR_EMPTY_DOCUMENT, 0, nullptr);
		return _errorID;
	}

	const size_t size = filelength;
	TIXMLASSERT(_charBuffer == nullptr);
	_charBuffer       = new char[size + 1];
	const size_t read = fread(_charBuffer, 1, size, fp);
	if (read != size)
	{
		SetError(XML_ERROR_FILE_READ_ERROR, 0, nullptr);
		return _errorID;
	}

	_charBuffer[size] = 0;

	Parse();
	return _errorID;
}


XMLError XMLDocument::SaveFile(const char* filename, const bool compact)
{
	if (!filename)
	{
		TIXMLASSERT(false);
		SetError(XML_ERROR_FILE_COULD_NOT_BE_OPENED, 0, "filename=<null>");
		return _errorID;
	}

	FILE* fp = callfopen(filename, "w");
	if (!fp)
	{
		SetError(XML_ERROR_FILE_COULD_NOT_BE_OPENED, 0, "filename=%s", filename);
		return _errorID;
	}
	SaveFile(fp, compact);
	fclose(fp);
	return _errorID;
}


XMLError XMLDocument::SaveFile(FILE* fp, const bool compact)
{
	// Clear any error from the last save, otherwise it will get reported
	// for *this* call.
	ClearError();
	XMLPrinter stream(fp, compact);
	Print(&stream);
	return _errorID;
}


XMLError XMLDocument::Parse(const char* xml, size_t len)
{
	Clear();

	if (len == 0 || !xml || !*xml)
	{
		SetError(XML_ERROR_EMPTY_DOCUMENT, 0, nullptr);
		return _errorID;
	}
	if (len == size_t(-1)) { len = strlen(xml); }
	TIXMLASSERT(_charBuffer == nullptr);
	_charBuffer = new char[len + 1];
	memcpy(_charBuffer, xml, len);
	_charBuffer[len] = 0;

	Parse();
	if (Error())
	{
		// clean up now essentially dangling memory.
		// and the parse fail can put objects in the
		// pools that are dead and inaccessible.
		DeleteChildren();
		_elementPool.Clear();
		_attributePool.Clear();
		_textPool.Clear();
		_commentPool.Clear();
	}
	return _errorID;
}


void XMLDocument::Print(XMLPrinter* streamer) const
{
	if (streamer) { Accept(streamer); }
	else
	{
		XMLPrinter stdoutStreamer(stdout);
		Accept(&stdoutStreamer);
	}
}


void XMLDocument::SetError(XMLError error, const int lineNum, const char* format, ...)
{
	TIXMLASSERT(error >= 0 && error < XML_ERROR_COUNT);
	_errorID      = error;
	_errorLineNum = lineNum;
	_errorStr.Reset();

	const size_t BUFFER_SIZE = 1000;
	char* buffer             = new char[BUFFER_SIZE];

	TIXMLASSERT(sizeof(error) <= sizeof(int));
	TIXML_SNPRINTF(buffer, BUFFER_SIZE, "Error=%s ErrorID=%d (0x%x) Line number=%d", ErrorIDToName(error), int(error), int(error), lineNum);

	if (format)
	{
		size_t len = strlen(buffer);
		TIXML_SNPRINTF(buffer + len, BUFFER_SIZE - len, ": ");
		len = strlen(buffer);

		va_list va;
		va_start(va, format);
		TIXML_VSNPRINTF(buffer + len, BUFFER_SIZE - len, format, va);
		va_end(va);
	}
	_errorStr.SetStr(buffer);
	delete[] buffer;
}


/*static*/
const char* XMLDocument::ErrorIDToName(const XMLError errorID)
{
	TIXMLASSERT(errorID >= 0 && errorID < XML_ERROR_COUNT);
	const char* errorName = _errorNames[errorID];
	TIXMLASSERT(errorName && errorName[0]);
	return errorName;
}

void XMLDocument::Parse()
{
	TIXMLASSERT(NoChildren()); // Clear() must have been called previously
	TIXMLASSERT(_charBuffer);
	_parseCurLineNum = 1;
	_parseLineNum    = 1;
	char* p          = _charBuffer;
	p                = XMLUtil::SkipWhiteSpace(p, &_parseCurLineNum);
	p                = const_cast<char*>(XMLUtil::ReadBOM(p, &_writeBOM));
	if (!*p)
	{
		SetError(XML_ERROR_EMPTY_DOCUMENT, 0, nullptr);
		return;
	}
	ParseDeep(p, nullptr, &_parseCurLineNum);
}

void XMLDocument::PushDepth()
{
	_parsingDepth++;
	if (_parsingDepth == TINYXML2_MAX_ELEMENT_DEPTH) { SetError(XML_ELEMENT_DEPTH_EXCEEDED, _parseCurLineNum, "Element nesting is too deep."); }
}

void XMLDocument::PopDepth()
{
	TIXMLASSERT(_parsingDepth > 0);
	--_parsingDepth;
}

XMLPrinter::XMLPrinter(FILE* file, const bool compact, const int depth) : _fp(file), _depth(depth), _compactMode(compact)
{
	for (int i = 0; i < ENTITY_RANGE; ++i)
	{
		_entityFlag[i]           = false;
		_restrictedEntityFlag[i] = false;
	}
	for (int i = 0; i < NUM_ENTITIES; ++i)
	{
		const char entityValue        = ENTITIES[i].value;
		const unsigned char flagIndex = static_cast<unsigned char>(entityValue);
		TIXMLASSERT(flagIndex < ENTITY_RANGE);
		_entityFlag[flagIndex] = true;
	}
	_restrictedEntityFlag[static_cast<unsigned char>('&')] = true;
	_restrictedEntityFlag[static_cast<unsigned char>('<')] = true;
	_restrictedEntityFlag[static_cast<unsigned char>('>')] = true;	// not required, but consistency is nice
	_buffer.Push(0);
}


void XMLPrinter::Print(const char* format, ...)
{
	va_list va;
	va_start(va, format);

	if (_fp) { vfprintf(_fp, format, va); }
	else
	{
		const int len = TIXML_VSCPRINTF(format, va);
		// Close out and re-start the va-args
		va_end(va);
		TIXMLASSERT(len >= 0);
		va_start(va, format);
		TIXMLASSERT(_buffer.Size() > 0 && _buffer[_buffer.Size() - 1] == 0);
		char* p = _buffer.PushArr(len) - 1;	// back up over the null terminator.
		TIXML_VSNPRINTF(p, len + 1, format, va);
	}
	va_end(va);
}


void XMLPrinter::Write(const char* data, const size_t size)
{
	if (_fp) { fwrite(data, sizeof(char), size, _fp); }
	else
	{
		char* p = _buffer.PushArr(int(size)) - 1;   // back up over the null terminator.
		memcpy(p, data, size);
		p[size] = 0;
	}
}


void XMLPrinter::Putc(const char ch)
{
	if (_fp) { fputc(ch, _fp); }
	else
	{
		char* p = _buffer.PushArr(sizeof(char)) - 1;   // back up over the null terminator.
		p[0]    = ch;
		p[1]    = 0;
	}
}


void XMLPrinter::PrintString(const char* p, const bool restricted)
{
	// Look for runs of bytes between entities to print.
	const char* q = p;

	if (_processEntities)
	{
		const bool* flag = restricted ? _restrictedEntityFlag : _entityFlag;
		while (*q)
		{
			TIXMLASSERT(p <= q);
			// Remember, char is sometimes signed. (How many times has that bitten me?)
			if (*q > 0 && *q < ENTITY_RANGE)
			{
				// Check for entities. If one is found, flush
				// the stream up until the entity, write the
				// entity, and keep looking.
				if (flag[static_cast<unsigned char>(*q)])
				{
					while (p < q)
					{
						const size_t delta = q - p;
						const int toPrint  = (INT_MAX < delta) ? INT_MAX : int(delta);
						Write(p, toPrint);
						p += toPrint;
					}
					bool entityPatternPrinted = false;
					for (int i = 0; i < NUM_ENTITIES; ++i)
					{
						if (ENTITIES[i].value == *q)
						{
							Putc('&');
							Write(ENTITIES[i].pattern, ENTITIES[i].length);
							Putc(';');
							entityPatternPrinted = true;
							break;
						}
					}
					if (!entityPatternPrinted)
					{
						// TIXMLASSERT( entityPatternPrinted ) causes gcc -Wunused-but-set-variable in release
						TIXMLASSERT(false);
					}
					++p;
				}
			}
			++q;
			TIXMLASSERT(p <= q);
		}
		// Flush the remaining string. This will be the entire
		// string if an entity wasn't found.
		if (p < q)
		{
			const size_t delta = q - p;
			const int toPrint  = (INT_MAX < delta) ? INT_MAX : int(delta);
			Write(p, toPrint);
		}
	}
	else { Write(p); }
}


void XMLPrinter::PushHeader(const bool writeBOM, const bool writeDec)
{
	if (writeBOM)
	{
		static const unsigned char bom[] = { TIXML_UTF_LEAD_0, TIXML_UTF_LEAD_1, TIXML_UTF_LEAD_2, 0 };
		Write(reinterpret_cast<const char*>(bom));
	}
	if (writeDec) { PushDeclaration("xml version=\"1.0\""); }
}


void XMLPrinter::OpenElement(const char* name, const bool compactMode)
{
	SealElementIfJustOpened();
	_stack.Push(name);

	if (_textDepth < 0 && !_firstElement && !compactMode) { Putc('\n'); }
	if (!compactMode) { PrintSpace(_depth); }

	Write("<");
	Write(name);

	_elementJustOpened = true;
	_firstElement      = false;
	++_depth;
}


void XMLPrinter::PushAttribute(const char* name, const char* value)
{
	TIXMLASSERT(_elementJustOpened);
	Putc(' ');
	Write(name);
	Write("=\"");
	PrintString(value, false);
	Putc('\"');
}


void XMLPrinter::PushAttribute(const char* name, const int value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	PushAttribute(name, buf);
}


void XMLPrinter::PushAttribute(const char* name, const unsigned value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	PushAttribute(name, buf);
}


void XMLPrinter::PushAttribute(const char* name, const int64_t value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	PushAttribute(name, buf);
}


void XMLPrinter::PushAttribute(const char* name, const bool value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	PushAttribute(name, buf);
}


void XMLPrinter::PushAttribute(const char* name, const double value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	PushAttribute(name, buf);
}


void XMLPrinter::CloseElement(const bool compactMode)
{
	--_depth;
	const char* name = _stack.Pop();

	if (_elementJustOpened) { Write("/>"); }
	else
	{
		if (_textDepth < 0 && !compactMode)
		{
			Putc('\n');
			PrintSpace(_depth);
		}
		Write("</");
		Write(name);
		Write(">");
	}

	if (_textDepth == _depth) { _textDepth = -1; }
	if (_depth == 0 && !compactMode) { Putc('\n'); }
	_elementJustOpened = false;
}


void XMLPrinter::SealElementIfJustOpened()
{
	if (!_elementJustOpened) { return; }
	_elementJustOpened = false;
	Putc('>');
}


void XMLPrinter::PushText(const char* text, const bool cdata)
{
	_textDepth = _depth - 1;

	SealElementIfJustOpened();
	if (cdata)
	{
		Write("<![CDATA[");
		Write(text);
		Write("]]>");
	}
	else { PrintString(text, true); }
}

void XMLPrinter::PushText(const int64_t value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	PushText(buf, false);
}

void XMLPrinter::PushText(const int value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	PushText(buf, false);
}


void XMLPrinter::PushText(const unsigned value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	PushText(buf, false);
}


void XMLPrinter::PushText(const bool value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	PushText(buf, false);
}


void XMLPrinter::PushText(const float value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	PushText(buf, false);
}


void XMLPrinter::PushText(const double value)
{
	char buf[BUF_SIZE];
	XMLUtil::ToStr(value, buf, BUF_SIZE);
	PushText(buf, false);
}


void XMLPrinter::PushComment(const char* comment)
{
	SealElementIfJustOpened();
	if (_textDepth < 0 && !_firstElement && !_compactMode)
	{
		Putc('\n');
		PrintSpace(_depth);
	}
	_firstElement = false;

	Write("<!--");
	Write(comment);
	Write("-->");
}


void XMLPrinter::PushDeclaration(const char* value)
{
	SealElementIfJustOpened();
	if (_textDepth < 0 && !_firstElement && !_compactMode)
	{
		Putc('\n');
		PrintSpace(_depth);
	}
	_firstElement = false;

	Write("<?");
	Write(value);
	Write("?>");
}


void XMLPrinter::PushUnknown(const char* value)
{
	SealElementIfJustOpened();
	if (_textDepth < 0 && !_firstElement && !_compactMode)
	{
		Putc('\n');
		PrintSpace(_depth);
	}
	_firstElement = false;

	Write("<!");
	Write(value);
	Putc('>');
}


bool XMLPrinter::VisitEnter(const XMLDocument& doc)
{
	_processEntities = doc.ProcessEntities();
	if (doc.HasBOM()) { PushHeader(true, false); }
	return true;
}


bool XMLPrinter::VisitEnter(const XMLElement& element, const XMLAttribute* attribute)
{
	const XMLElement* parentElem = nullptr;
	if (element.Parent()) { parentElem = element.Parent()->ToElement(); }
	const bool compactMode = parentElem ? CompactMode(*parentElem) : _compactMode;
	OpenElement(element.Name(), compactMode);
	while (attribute)
	{
		PushAttribute(attribute->Name(), attribute->Value());
		attribute = attribute->Next();
	}
	return true;
}


bool XMLPrinter::VisitExit(const XMLElement& element)
{
	CloseElement(CompactMode(element));
	return true;
}


bool XMLPrinter::Visit(const XMLText& text)
{
	PushText(text.Value(), text.CData());
	return true;
}


bool XMLPrinter::Visit(const XMLComment& comment)
{
	PushComment(comment.Value());
	return true;
}

bool XMLPrinter::Visit(const XMLDeclaration& declaration)
{
	PushDeclaration(declaration.Value());
	return true;
}


bool XMLPrinter::Visit(const XMLUnknown& unknown)
{
	PushUnknown(unknown.Value());
	return true;
}
}   // namespace tinyxml2