kc3-lang/libxml2/parserInternals.c

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• Hash : aab584dc
  Author :
  Date : 2022-03-06T23:23:43
  

  Clean up encoding switching code
  
  - Remove xmlSwitchToEncodingInt which was basically just a wrapper
    around xmlSwitchInputEncodingInt.
  - Simplify xmlSwitchEncoding.
  - Improve error handling in xmlSwitchInputEncodingInt.
  - Deprecate xmlSwitchInputEncoding.
  

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• parserInternals.c

• /*
   * parserInternals.c : Internal routines (and obsolete ones) needed for the
   *                     XML and HTML parsers.
   *
   * See Copyright for the status of this software.
   *
   * daniel@veillard.com
   */
  
  #define IN_LIBXML
  #include "libxml.h"
  
  #if defined(_WIN32)
  #define XML_DIR_SEP '\\'
  #else
  #define XML_DIR_SEP '/'
  #endif
  
  #include <string.h>
  #include <ctype.h>
  #include <stdlib.h>
  
  #include <libxml/xmlmemory.h>
  #include <libxml/tree.h>
  #include <libxml/parser.h>
  #include <libxml/parserInternals.h>
  #include <libxml/valid.h>
  #include <libxml/entities.h>
  #include <libxml/xmlerror.h>
  #include <libxml/encoding.h>
  #include <libxml/valid.h>
  #include <libxml/xmlIO.h>
  #include <libxml/uri.h>
  #include <libxml/dict.h>
  #include <libxml/SAX.h>
  #ifdef LIBXML_CATALOG_ENABLED
  #include <libxml/catalog.h>
  #endif
  #include <libxml/globals.h>
  #include <libxml/chvalid.h>
  
  #define CUR(ctxt) ctxt->input->cur
  #define END(ctxt) ctxt->input->end
  #define VALID_CTXT(ctxt) (CUR(ctxt) <= END(ctxt))
  
  #include "buf.h"
  #include "enc.h"
  
  /*
   * Various global defaults for parsing
   */
  
  /**
   * xmlCheckVersion:
   * @version: the include version number
   *
   * check the compiled lib version against the include one.
   * This can warn or immediately kill the application
   */
  void
  xmlCheckVersion(int version) {
      int myversion = (int) LIBXML_VERSION;
  
      xmlInitParser();
  
      if ((myversion / 10000) != (version / 10000)) {
  	xmlGenericError(xmlGenericErrorContext,
  		"Fatal: program compiled against libxml %d using libxml %d\n",
  		(version / 10000), (myversion / 10000));
  	fprintf(stderr,
  		"Fatal: program compiled against libxml %d using libxml %d\n",
  		(version / 10000), (myversion / 10000));
      }
      if ((myversion / 100) < (version / 100)) {
  	xmlGenericError(xmlGenericErrorContext,
  		"Warning: program compiled against libxml %d using older %d\n",
  		(version / 100), (myversion / 100));
      }
  }
  
  
  /************************************************************************
   *									*
   *		Some factorized error routines				*
   *									*
   ************************************************************************/
  
  
  /**
   * xmlErrMemory:
   * @ctxt:  an XML parser context
   * @extra:  extra information
   *
   * Handle a redefinition of attribute error
   */
  void
  xmlErrMemory(xmlParserCtxtPtr ctxt, const char *extra)
  {
      if ((ctxt != NULL) && (ctxt->disableSAX != 0) &&
          (ctxt->instate == XML_PARSER_EOF))
  	return;
      if (ctxt != NULL) {
          ctxt->errNo = XML_ERR_NO_MEMORY;
          ctxt->instate = XML_PARSER_EOF;
          ctxt->disableSAX = 1;
      }
      if (extra)
          __xmlRaiseError(NULL, NULL, NULL, ctxt, NULL, XML_FROM_PARSER,
                          XML_ERR_NO_MEMORY, XML_ERR_FATAL, NULL, 0, extra,
                          NULL, NULL, 0, 0,
                          "Memory allocation failed : %s\n", extra);
      else
          __xmlRaiseError(NULL, NULL, NULL, ctxt, NULL, XML_FROM_PARSER,
                          XML_ERR_NO_MEMORY, XML_ERR_FATAL, NULL, 0, NULL,
                          NULL, NULL, 0, 0, "Memory allocation failed\n");
  }
  
  /**
   * __xmlErrEncoding:
   * @ctxt:  an XML parser context
   * @xmlerr:  the error number
   * @msg:  the error message
   * @str1:  an string info
   * @str2:  an string info
   *
   * Handle an encoding error
   */
  void
  __xmlErrEncoding(xmlParserCtxtPtr ctxt, xmlParserErrors xmlerr,
                   const char *msg, const xmlChar * str1, const xmlChar * str2)
  {
      if ((ctxt != NULL) && (ctxt->disableSAX != 0) &&
          (ctxt->instate == XML_PARSER_EOF))
  	return;
      if (ctxt != NULL)
          ctxt->errNo = xmlerr;
      __xmlRaiseError(NULL, NULL, NULL,
                      ctxt, NULL, XML_FROM_PARSER, xmlerr, XML_ERR_FATAL,
                      NULL, 0, (const char *) str1, (const char *) str2,
                      NULL, 0, 0, msg, str1, str2);
      if (ctxt != NULL) {
          ctxt->wellFormed = 0;
          if (ctxt->recovery == 0)
              ctxt->disableSAX = 1;
      }
  }
  
  /**
   * xmlErrInternal:
   * @ctxt:  an XML parser context
   * @msg:  the error message
   * @str:  error information
   *
   * Handle an internal error
   */
  static void LIBXML_ATTR_FORMAT(2,0)
  xmlErrInternal(xmlParserCtxtPtr ctxt, const char *msg, const xmlChar * str)
  {
      if ((ctxt != NULL) && (ctxt->disableSAX != 0) &&
          (ctxt->instate == XML_PARSER_EOF))
  	return;
      if (ctxt != NULL)
          ctxt->errNo = XML_ERR_INTERNAL_ERROR;
      __xmlRaiseError(NULL, NULL, NULL,
                      ctxt, NULL, XML_FROM_PARSER, XML_ERR_INTERNAL_ERROR,
                      XML_ERR_FATAL, NULL, 0, (const char *) str, NULL, NULL,
                      0, 0, msg, str);
      if (ctxt != NULL) {
          ctxt->wellFormed = 0;
          if (ctxt->recovery == 0)
              ctxt->disableSAX = 1;
      }
  }
  
  /**
   * xmlErrEncodingInt:
   * @ctxt:  an XML parser context
   * @error:  the error number
   * @msg:  the error message
   * @val:  an integer value
   *
   * n encoding error
   */
  static void LIBXML_ATTR_FORMAT(3,0)
  xmlErrEncodingInt(xmlParserCtxtPtr ctxt, xmlParserErrors error,
                    const char *msg, int val)
  {
      if ((ctxt != NULL) && (ctxt->disableSAX != 0) &&
          (ctxt->instate == XML_PARSER_EOF))
  	return;
      if (ctxt != NULL)
          ctxt->errNo = error;
      __xmlRaiseError(NULL, NULL, NULL,
                      ctxt, NULL, XML_FROM_PARSER, error, XML_ERR_FATAL,
                      NULL, 0, NULL, NULL, NULL, val, 0, msg, val);
      if (ctxt != NULL) {
          ctxt->wellFormed = 0;
          if (ctxt->recovery == 0)
              ctxt->disableSAX = 1;
      }
  }
  
  /**
   * xmlIsLetter:
   * @c:  an unicode character (int)
   *
   * Check whether the character is allowed by the production
   * [84] Letter ::= BaseChar | Ideographic
   *
   * Returns 0 if not, non-zero otherwise
   */
  int
  xmlIsLetter(int c) {
      return(IS_BASECHAR(c) || IS_IDEOGRAPHIC(c));
  }
  
  /************************************************************************
   *									*
   *		Input handling functions for progressive parsing	*
   *									*
   ************************************************************************/
  
  /* #define DEBUG_INPUT */
  /* #define DEBUG_STACK */
  /* #define DEBUG_PUSH */
  
  
  /* we need to keep enough input to show errors in context */
  #define LINE_LEN        80
  
  #ifdef DEBUG_INPUT
  #define CHECK_BUFFER(in) check_buffer(in)
  
  static
  void check_buffer(xmlParserInputPtr in) {
      if (in->base != xmlBufContent(in->buf->buffer)) {
          xmlGenericError(xmlGenericErrorContext,
  		"xmlParserInput: base mismatch problem\n");
      }
      if (in->cur < in->base) {
          xmlGenericError(xmlGenericErrorContext,
  		"xmlParserInput: cur < base problem\n");
      }
      if (in->cur > in->base + xmlBufUse(in->buf->buffer)) {
          xmlGenericError(xmlGenericErrorContext,
  		"xmlParserInput: cur > base + use problem\n");
      }
      xmlGenericError(xmlGenericErrorContext,"buffer %x : content %x, cur %d, use %d\n",
              (int) in, (int) xmlBufContent(in->buf->buffer), in->cur - in->base,
  	    xmlBufUse(in->buf->buffer));
  }
  
  #else
  #define CHECK_BUFFER(in)
  #endif
  
  
  /**
   * xmlParserInputRead:
   * @in:  an XML parser input
   * @len:  an indicative size for the lookahead
   *
   * This function was internal and is deprecated.
   *
   * Returns -1 as this is an error to use it.
   */
  int
  xmlParserInputRead(xmlParserInputPtr in ATTRIBUTE_UNUSED, int len ATTRIBUTE_UNUSED) {
      return(-1);
  }
  
  /**
   * xmlParserInputGrow:
   * @in:  an XML parser input
   * @len:  an indicative size for the lookahead
   *
   * This function increase the input for the parser. It tries to
   * preserve pointers to the input buffer, and keep already read data
   *
   * Returns the amount of char read, or -1 in case of error, 0 indicate the
   * end of this entity
   */
  int
  xmlParserInputGrow(xmlParserInputPtr in, int len) {
      int ret;
      size_t indx;
  
      if ((in == NULL) || (len < 0)) return(-1);
  #ifdef DEBUG_INPUT
      xmlGenericError(xmlGenericErrorContext, "Grow\n");
  #endif
      if (in->buf == NULL) return(-1);
      if (in->base == NULL) return(-1);
      if (in->cur == NULL) return(-1);
      if (in->buf->buffer == NULL) return(-1);
  
      CHECK_BUFFER(in);
  
      indx = in->cur - in->base;
      if (xmlBufUse(in->buf->buffer) > (unsigned int) indx + INPUT_CHUNK) {
  
  	CHECK_BUFFER(in);
  
          return(0);
      }
      if (in->buf->readcallback != NULL) {
  	ret = xmlParserInputBufferGrow(in->buf, len);
      } else
          return(0);
  
      in->base = xmlBufContent(in->buf->buffer);
      in->cur = in->base + indx;
      in->end = xmlBufEnd(in->buf->buffer);
  
      CHECK_BUFFER(in);
  
      return(ret);
  }
  
  /**
   * xmlParserInputShrink:
   * @in:  an XML parser input
   *
   * This function removes used input for the parser.
   */
  void
  xmlParserInputShrink(xmlParserInputPtr in) {
      size_t used;
      size_t ret;
  
  #ifdef DEBUG_INPUT
      xmlGenericError(xmlGenericErrorContext, "Shrink\n");
  #endif
      if (in == NULL) return;
      if (in->buf == NULL) return;
      if (in->base == NULL) return;
      if (in->cur == NULL) return;
      if (in->buf->buffer == NULL) return;
  
      CHECK_BUFFER(in);
  
      used = in->cur - in->base;
      /*
       * Do not shrink on large buffers whose only a tiny fraction
       * was consumed
       */
      if (used > INPUT_CHUNK) {
  	ret = xmlBufShrink(in->buf->buffer, used - LINE_LEN);
  	if (ret > 0) {
              used -= ret;
  	    in->consumed += ret;
  	}
      }
  
      if (xmlBufUse(in->buf->buffer) <= INPUT_CHUNK) {
          xmlParserInputBufferRead(in->buf, 2 * INPUT_CHUNK);
      }
  
      in->base = xmlBufContent(in->buf->buffer);
      in->cur = in->base + used;
      in->end = xmlBufEnd(in->buf->buffer);
  
      CHECK_BUFFER(in);
  }
  
  /************************************************************************
   *									*
   *		UTF8 character input and related functions		*
   *									*
   ************************************************************************/
  
  /**
   * xmlNextChar:
   * @ctxt:  the XML parser context
   *
   * Skip to the next char input char.
   */
  
  void
  xmlNextChar(xmlParserCtxtPtr ctxt)
  {
      if ((ctxt == NULL) || (ctxt->instate == XML_PARSER_EOF) ||
          (ctxt->input == NULL))
          return;
  
      if (!(VALID_CTXT(ctxt))) {
          xmlErrInternal(ctxt, "Parser input data memory error\n", NULL);
  	ctxt->errNo = XML_ERR_INTERNAL_ERROR;
          xmlStopParser(ctxt);
  	return;
      }
  
      if ((*ctxt->input->cur == 0) &&
          (xmlParserInputGrow(ctxt->input, INPUT_CHUNK) <= 0)) {
          return;
      }
  
      if (ctxt->charset == XML_CHAR_ENCODING_UTF8) {
          const unsigned char *cur;
          unsigned char c;
  
          /*
           *   2.11 End-of-Line Handling
           *   the literal two-character sequence "#xD#xA" or a standalone
           *   literal #xD, an XML processor must pass to the application
           *   the single character #xA.
           */
          if (*(ctxt->input->cur) == '\n') {
              ctxt->input->line++; ctxt->input->col = 1;
          } else
              ctxt->input->col++;
  
          /*
           * We are supposed to handle UTF8, check it's valid
           * From rfc2044: encoding of the Unicode values on UTF-8:
           *
           * UCS-4 range (hex.)           UTF-8 octet sequence (binary)
           * 0000 0000-0000 007F   0xxxxxxx
           * 0000 0080-0000 07FF   110xxxxx 10xxxxxx
           * 0000 0800-0000 FFFF   1110xxxx 10xxxxxx 10xxxxxx
           *
           * Check for the 0x110000 limit too
           */
          cur = ctxt->input->cur;
  
          c = *cur;
          if (c & 0x80) {
              if (c == 0xC0)
  	        goto encoding_error;
              if (cur[1] == 0) {
                  xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
                  cur = ctxt->input->cur;
              }
              if ((cur[1] & 0xc0) != 0x80)
                  goto encoding_error;
              if ((c & 0xe0) == 0xe0) {
                  unsigned int val;
  
                  if (cur[2] == 0) {
                      xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
                      cur = ctxt->input->cur;
                  }
                  if ((cur[2] & 0xc0) != 0x80)
                      goto encoding_error;
                  if ((c & 0xf0) == 0xf0) {
                      if (cur[3] == 0) {
                          xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
                          cur = ctxt->input->cur;
                      }
                      if (((c & 0xf8) != 0xf0) ||
                          ((cur[3] & 0xc0) != 0x80))
                          goto encoding_error;
                      /* 4-byte code */
                      ctxt->input->cur += 4;
                      val = (cur[0] & 0x7) << 18;
                      val |= (cur[1] & 0x3f) << 12;
                      val |= (cur[2] & 0x3f) << 6;
                      val |= cur[3] & 0x3f;
                  } else {
                      /* 3-byte code */
                      ctxt->input->cur += 3;
                      val = (cur[0] & 0xf) << 12;
                      val |= (cur[1] & 0x3f) << 6;
                      val |= cur[2] & 0x3f;
                  }
                  if (((val > 0xd7ff) && (val < 0xe000)) ||
                      ((val > 0xfffd) && (val < 0x10000)) ||
                      (val >= 0x110000)) {
  		xmlErrEncodingInt(ctxt, XML_ERR_INVALID_CHAR,
  				  "Char 0x%X out of allowed range\n",
  				  val);
                  }
              } else
                  /* 2-byte code */
                  ctxt->input->cur += 2;
          } else
              /* 1-byte code */
              ctxt->input->cur++;
      } else {
          /*
           * Assume it's a fixed length encoding (1) with
           * a compatible encoding for the ASCII set, since
           * XML constructs only use < 128 chars
           */
  
          if (*(ctxt->input->cur) == '\n') {
              ctxt->input->line++; ctxt->input->col = 1;
          } else
              ctxt->input->col++;
          ctxt->input->cur++;
      }
      if (*ctxt->input->cur == 0)
          xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
      return;
  encoding_error:
      /*
       * If we detect an UTF8 error that probably mean that the
       * input encoding didn't get properly advertised in the
       * declaration header. Report the error and switch the encoding
       * to ISO-Latin-1 (if you don't like this policy, just declare the
       * encoding !)
       */
      if ((ctxt == NULL) || (ctxt->input == NULL) ||
          (ctxt->input->end - ctxt->input->cur < 4)) {
  	__xmlErrEncoding(ctxt, XML_ERR_INVALID_CHAR,
  		     "Input is not proper UTF-8, indicate encoding !\n",
  		     NULL, NULL);
      } else {
          char buffer[150];
  
  	snprintf(buffer, 149, "Bytes: 0x%02X 0x%02X 0x%02X 0x%02X\n",
  			ctxt->input->cur[0], ctxt->input->cur[1],
  			ctxt->input->cur[2], ctxt->input->cur[3]);
  	__xmlErrEncoding(ctxt, XML_ERR_INVALID_CHAR,
  		     "Input is not proper UTF-8, indicate encoding !\n%s",
  		     BAD_CAST buffer, NULL);
      }
      ctxt->charset = XML_CHAR_ENCODING_8859_1;
      ctxt->input->cur++;
      return;
  }
  
  /**
   * xmlCurrentChar:
   * @ctxt:  the XML parser context
   * @len:  pointer to the length of the char read
   *
   * The current char value, if using UTF-8 this may actually span multiple
   * bytes in the input buffer. Implement the end of line normalization:
   * 2.11 End-of-Line Handling
   * Wherever an external parsed entity or the literal entity value
   * of an internal parsed entity contains either the literal two-character
   * sequence "#xD#xA" or a standalone literal #xD, an XML processor
   * must pass to the application the single character #xA.
   * This behavior can conveniently be produced by normalizing all
   * line breaks to #xA on input, before parsing.)
   *
   * Returns the current char value and its length
   */
  
  int
  xmlCurrentChar(xmlParserCtxtPtr ctxt, int *len) {
      if ((ctxt == NULL) || (len == NULL) || (ctxt->input == NULL)) return(0);
      if (ctxt->instate == XML_PARSER_EOF)
  	return(0);
  
      if ((*ctxt->input->cur >= 0x20) && (*ctxt->input->cur <= 0x7F)) {
  	    *len = 1;
  	    return((int) *ctxt->input->cur);
      }
      if (ctxt->charset == XML_CHAR_ENCODING_UTF8) {
  	/*
  	 * We are supposed to handle UTF8, check it's valid
  	 * From rfc2044: encoding of the Unicode values on UTF-8:
  	 *
  	 * UCS-4 range (hex.)           UTF-8 octet sequence (binary)
  	 * 0000 0000-0000 007F   0xxxxxxx
  	 * 0000 0080-0000 07FF   110xxxxx 10xxxxxx
  	 * 0000 0800-0000 FFFF   1110xxxx 10xxxxxx 10xxxxxx
  	 *
  	 * Check for the 0x110000 limit too
  	 */
  	const unsigned char *cur = ctxt->input->cur;
  	unsigned char c;
  	unsigned int val;
  
  	c = *cur;
  	if (c & 0x80) {
  	    if (((c & 0x40) == 0) || (c == 0xC0))
  		goto encoding_error;
  	    if (cur[1] == 0) {
  		xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
                  cur = ctxt->input->cur;
              }
  	    if ((cur[1] & 0xc0) != 0x80)
  		goto encoding_error;
  	    if ((c & 0xe0) == 0xe0) {
  		if (cur[2] == 0) {
  		    xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
                      cur = ctxt->input->cur;
                  }
  		if ((cur[2] & 0xc0) != 0x80)
  		    goto encoding_error;
  		if ((c & 0xf0) == 0xf0) {
  		    if (cur[3] == 0) {
  			xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
                          cur = ctxt->input->cur;
                      }
  		    if (((c & 0xf8) != 0xf0) ||
  			((cur[3] & 0xc0) != 0x80))
  			goto encoding_error;
  		    /* 4-byte code */
  		    *len = 4;
  		    val = (cur[0] & 0x7) << 18;
  		    val |= (cur[1] & 0x3f) << 12;
  		    val |= (cur[2] & 0x3f) << 6;
  		    val |= cur[3] & 0x3f;
  		    if (val < 0x10000)
  			goto encoding_error;
  		} else {
  		  /* 3-byte code */
  		    *len = 3;
  		    val = (cur[0] & 0xf) << 12;
  		    val |= (cur[1] & 0x3f) << 6;
  		    val |= cur[2] & 0x3f;
  		    if (val < 0x800)
  			goto encoding_error;
  		}
  	    } else {
  	      /* 2-byte code */
  		*len = 2;
  		val = (cur[0] & 0x1f) << 6;
  		val |= cur[1] & 0x3f;
  		if (val < 0x80)
  		    goto encoding_error;
  	    }
  	    if (!IS_CHAR(val)) {
  	        xmlErrEncodingInt(ctxt, XML_ERR_INVALID_CHAR,
  				  "Char 0x%X out of allowed range\n", val);
  	    }
  	    return(val);
  	} else {
  	    /* 1-byte code */
  	    *len = 1;
  	    if (*ctxt->input->cur == 0)
  		xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
  	    if ((*ctxt->input->cur == 0) &&
  	        (ctxt->input->end > ctxt->input->cur)) {
  	        xmlErrEncodingInt(ctxt, XML_ERR_INVALID_CHAR,
  				  "Char 0x0 out of allowed range\n", 0);
  	    }
  	    if (*ctxt->input->cur == 0xD) {
  		if (ctxt->input->cur[1] == 0xA) {
  		    ctxt->input->cur++;
  		}
  		return(0xA);
  	    }
  	    return((int) *ctxt->input->cur);
  	}
      }
      /*
       * Assume it's a fixed length encoding (1) with
       * a compatible encoding for the ASCII set, since
       * XML constructs only use < 128 chars
       */
      *len = 1;
      if (*ctxt->input->cur == 0xD) {
  	if (ctxt->input->cur[1] == 0xA) {
  	    ctxt->input->cur++;
  	}
  	return(0xA);
      }
      return((int) *ctxt->input->cur);
  encoding_error:
      /*
       * An encoding problem may arise from a truncated input buffer
       * splitting a character in the middle. In that case do not raise
       * an error but return 0 to indicate an end of stream problem
       */
      if (ctxt->input->end - ctxt->input->cur < 4) {
  	*len = 0;
  	return(0);
      }
  
      /*
       * If we detect an UTF8 error that probably mean that the
       * input encoding didn't get properly advertised in the
       * declaration header. Report the error and switch the encoding
       * to ISO-Latin-1 (if you don't like this policy, just declare the
       * encoding !)
       */
      {
          char buffer[150];
  
  	snprintf(&buffer[0], 149, "Bytes: 0x%02X 0x%02X 0x%02X 0x%02X\n",
  			ctxt->input->cur[0], ctxt->input->cur[1],
  			ctxt->input->cur[2], ctxt->input->cur[3]);
  	__xmlErrEncoding(ctxt, XML_ERR_INVALID_CHAR,
  		     "Input is not proper UTF-8, indicate encoding !\n%s",
  		     BAD_CAST buffer, NULL);
      }
      ctxt->charset = XML_CHAR_ENCODING_8859_1;
      *len = 1;
      return((int) *ctxt->input->cur);
  }
  
  /**
   * xmlStringCurrentChar:
   * @ctxt:  the XML parser context
   * @cur:  pointer to the beginning of the char
   * @len:  pointer to the length of the char read
   *
   * The current char value, if using UTF-8 this may actually span multiple
   * bytes in the input buffer.
   *
   * Returns the current char value and its length
   */
  
  int
  xmlStringCurrentChar(xmlParserCtxtPtr ctxt, const xmlChar * cur, int *len)
  {
      if ((len == NULL) || (cur == NULL)) return(0);
      if ((ctxt == NULL) || (ctxt->charset == XML_CHAR_ENCODING_UTF8)) {
          /*
           * We are supposed to handle UTF8, check it's valid
           * From rfc2044: encoding of the Unicode values on UTF-8:
           *
           * UCS-4 range (hex.)           UTF-8 octet sequence (binary)
           * 0000 0000-0000 007F   0xxxxxxx
           * 0000 0080-0000 07FF   110xxxxx 10xxxxxx
           * 0000 0800-0000 FFFF   1110xxxx 10xxxxxx 10xxxxxx
           *
           * Check for the 0x110000 limit too
           */
          unsigned char c;
          unsigned int val;
  
          c = *cur;
          if (c & 0x80) {
              if ((cur[1] & 0xc0) != 0x80)
                  goto encoding_error;
              if ((c & 0xe0) == 0xe0) {
  
                  if ((cur[2] & 0xc0) != 0x80)
                      goto encoding_error;
                  if ((c & 0xf0) == 0xf0) {
                      if (((c & 0xf8) != 0xf0) || ((cur[3] & 0xc0) != 0x80))
                          goto encoding_error;
                      /* 4-byte code */
                      *len = 4;
                      val = (cur[0] & 0x7) << 18;
                      val |= (cur[1] & 0x3f) << 12;
                      val |= (cur[2] & 0x3f) << 6;
                      val |= cur[3] & 0x3f;
                  } else {
                      /* 3-byte code */
                      *len = 3;
                      val = (cur[0] & 0xf) << 12;
                      val |= (cur[1] & 0x3f) << 6;
                      val |= cur[2] & 0x3f;
                  }
              } else {
                  /* 2-byte code */
                  *len = 2;
                  val = (cur[0] & 0x1f) << 6;
                  val |= cur[1] & 0x3f;
              }
              if (!IS_CHAR(val)) {
  	        xmlErrEncodingInt(ctxt, XML_ERR_INVALID_CHAR,
  				  "Char 0x%X out of allowed range\n", val);
              }
              return (val);
          } else {
              /* 1-byte code */
              *len = 1;
              return ((int) *cur);
          }
      }
      /*
       * Assume it's a fixed length encoding (1) with
       * a compatible encoding for the ASCII set, since
       * XML constructs only use < 128 chars
       */
      *len = 1;
      return ((int) *cur);
  encoding_error:
  
      /*
       * An encoding problem may arise from a truncated input buffer
       * splitting a character in the middle. In that case do not raise
       * an error but return 0 to indicate an end of stream problem
       */
      if ((ctxt == NULL) || (ctxt->input == NULL) ||
          (ctxt->input->end - ctxt->input->cur < 4)) {
  	*len = 0;
  	return(0);
      }
      /*
       * If we detect an UTF8 error that probably mean that the
       * input encoding didn't get properly advertised in the
       * declaration header. Report the error and switch the encoding
       * to ISO-Latin-1 (if you don't like this policy, just declare the
       * encoding !)
       */
      {
          char buffer[150];
  
  	snprintf(buffer, 149, "Bytes: 0x%02X 0x%02X 0x%02X 0x%02X\n",
  			ctxt->input->cur[0], ctxt->input->cur[1],
  			ctxt->input->cur[2], ctxt->input->cur[3]);
  	__xmlErrEncoding(ctxt, XML_ERR_INVALID_CHAR,
  		     "Input is not proper UTF-8, indicate encoding !\n%s",
  		     BAD_CAST buffer, NULL);
      }
      *len = 1;
      return ((int) *cur);
  }
  
  /**
   * xmlCopyCharMultiByte:
   * @out:  pointer to an array of xmlChar
   * @val:  the char value
   *
   * append the char value in the array
   *
   * Returns the number of xmlChar written
   */
  int
  xmlCopyCharMultiByte(xmlChar *out, int val) {
      if (out == NULL) return(0);
      /*
       * We are supposed to handle UTF8, check it's valid
       * From rfc2044: encoding of the Unicode values on UTF-8:
       *
       * UCS-4 range (hex.)           UTF-8 octet sequence (binary)
       * 0000 0000-0000 007F   0xxxxxxx
       * 0000 0080-0000 07FF   110xxxxx 10xxxxxx
       * 0000 0800-0000 FFFF   1110xxxx 10xxxxxx 10xxxxxx
       */
      if  (val >= 0x80) {
  	xmlChar *savedout = out;
  	int bits;
  	if (val <   0x800) { *out++= (val >>  6) | 0xC0;  bits=  0; }
  	else if (val < 0x10000) { *out++= (val >> 12) | 0xE0;  bits=  6;}
  	else if (val < 0x110000)  { *out++= (val >> 18) | 0xF0;  bits=  12; }
  	else {
  	    xmlErrEncodingInt(NULL, XML_ERR_INVALID_CHAR,
  		    "Internal error, xmlCopyCharMultiByte 0x%X out of bound\n",
  			      val);
  	    return(0);
  	}
  	for ( ; bits >= 0; bits-= 6)
  	    *out++= ((val >> bits) & 0x3F) | 0x80 ;
  	return (out - savedout);
      }
      *out = (xmlChar) val;
      return 1;
  }
  
  /**
   * xmlCopyChar:
   * @len:  Ignored, compatibility
   * @out:  pointer to an array of xmlChar
   * @val:  the char value
   *
   * append the char value in the array
   *
   * Returns the number of xmlChar written
   */
  
  int
  xmlCopyChar(int len ATTRIBUTE_UNUSED, xmlChar *out, int val) {
      if (out == NULL) return(0);
      /* the len parameter is ignored */
      if  (val >= 0x80) {
  	return(xmlCopyCharMultiByte (out, val));
      }
      *out = (xmlChar) val;
      return 1;
  }
  
  /************************************************************************
   *									*
   *		Commodity functions to switch encodings			*
   *									*
   ************************************************************************/
  
  static int
  xmlSwitchInputEncodingInt(xmlParserCtxtPtr ctxt, xmlParserInputPtr input,
                            xmlCharEncodingHandlerPtr handler, int len);
  /**
   * xmlSwitchEncoding:
   * @ctxt:  the parser context
   * @enc:  the encoding value (number)
   *
   * change the input functions when discovering the character encoding
   * of a given entity.
   *
   * Returns 0 in case of success, -1 otherwise
   */
  int
  xmlSwitchEncoding(xmlParserCtxtPtr ctxt, xmlCharEncoding enc)
  {
      xmlCharEncodingHandlerPtr handler;
      int len = -1;
      int ret;
  
      if (ctxt == NULL) return(-1);
      switch (enc) {
  	case XML_CHAR_ENCODING_ERROR:
  	    __xmlErrEncoding(ctxt, XML_ERR_UNKNOWN_ENCODING,
  	                   "encoding unknown\n", NULL, NULL);
  	    return(-1);
  	case XML_CHAR_ENCODING_NONE:
  	    /* let's assume it's UTF-8 without the XML decl */
  	    ctxt->charset = XML_CHAR_ENCODING_UTF8;
  	    return(0);
  	case XML_CHAR_ENCODING_UTF8:
  	    /* default encoding, no conversion should be needed */
  	    ctxt->charset = XML_CHAR_ENCODING_UTF8;
  
  	    /*
  	     * Errata on XML-1.0 June 20 2001
  	     * Specific handling of the Byte Order Mark for
  	     * UTF-8
  	     */
  	    if ((ctxt->input != NULL) &&
  		(ctxt->input->cur[0] == 0xEF) &&
  		(ctxt->input->cur[1] == 0xBB) &&
  		(ctxt->input->cur[2] == 0xBF)) {
  		ctxt->input->cur += 3;
  	    }
  	    return(0);
      case XML_CHAR_ENCODING_UTF16LE:
      case XML_CHAR_ENCODING_UTF16BE:
          /*The raw input characters are encoded
           *in UTF-16. As we expect this function
           *to be called after xmlCharEncInFunc, we expect
           *ctxt->input->cur to contain UTF-8 encoded characters.
           *So the raw UTF16 Byte Order Mark
           *has also been converted into
           *an UTF-8 BOM. Let's skip that BOM.
           */
          if ((ctxt->input != NULL) && (ctxt->input->cur != NULL) &&
              (ctxt->input->cur[0] == 0xEF) &&
              (ctxt->input->cur[1] == 0xBB) &&
              (ctxt->input->cur[2] == 0xBF)) {
              ctxt->input->cur += 3;
          }
          len = 90;
  	break;
      case XML_CHAR_ENCODING_UCS2:
          len = 90;
  	break;
      case XML_CHAR_ENCODING_UCS4BE:
      case XML_CHAR_ENCODING_UCS4LE:
      case XML_CHAR_ENCODING_UCS4_2143:
      case XML_CHAR_ENCODING_UCS4_3412:
          len = 180;
  	break;
      case XML_CHAR_ENCODING_EBCDIC:
      case XML_CHAR_ENCODING_8859_1:
      case XML_CHAR_ENCODING_8859_2:
      case XML_CHAR_ENCODING_8859_3:
      case XML_CHAR_ENCODING_8859_4:
      case XML_CHAR_ENCODING_8859_5:
      case XML_CHAR_ENCODING_8859_6:
      case XML_CHAR_ENCODING_8859_7:
      case XML_CHAR_ENCODING_8859_8:
      case XML_CHAR_ENCODING_8859_9:
      case XML_CHAR_ENCODING_ASCII:
      case XML_CHAR_ENCODING_2022_JP:
      case XML_CHAR_ENCODING_SHIFT_JIS:
      case XML_CHAR_ENCODING_EUC_JP:
          len = 45;
  	break;
      }
      handler = xmlGetCharEncodingHandler(enc);
      if (handler == NULL) {
  	/*
  	 * Default handlers.
  	 */
  	switch (enc) {
  	    case XML_CHAR_ENCODING_ASCII:
  		/* default encoding, no conversion should be needed */
  		ctxt->charset = XML_CHAR_ENCODING_UTF8;
  		return(0);
  	    case XML_CHAR_ENCODING_8859_1:
  		if ((ctxt->inputNr == 1) &&
  		    (ctxt->encoding == NULL) &&
  		    (ctxt->input != NULL) &&
  		    (ctxt->input->encoding != NULL)) {
  		    ctxt->encoding = xmlStrdup(ctxt->input->encoding);
  		}
  		ctxt->charset = enc;
  		return(0);
  	    default:
  		__xmlErrEncoding(ctxt, XML_ERR_UNSUPPORTED_ENCODING,
                          "encoding not supported: %s\n",
  			BAD_CAST xmlGetCharEncodingName(enc), NULL);
                  /*
                   * TODO: We could recover from errors in external entities
                   * if we didn't stop the parser. But most callers of this
                   * function don't check the return value.
                   */
                  xmlStopParser(ctxt);
                  return(-1);
          }
      }
      ret = xmlSwitchInputEncodingInt(ctxt, ctxt->input, handler, len);
      if ((ret < 0) || (ctxt->errNo == XML_I18N_CONV_FAILED)) {
          /*
  	 * on encoding conversion errors, stop the parser
  	 */
          xmlStopParser(ctxt);
  	ctxt->errNo = XML_I18N_CONV_FAILED;
      }
      return(ret);
  }
  
  /**
   * xmlSwitchInputEncodingInt:
   * @ctxt:  the parser context
   * @input:  the input stream
   * @handler:  the encoding handler
   * @len:  the number of bytes to convert for the first line or -1
   *
   * change the input functions when discovering the character encoding
   * of a given entity.
   *
   * Returns 0 in case of success, -1 otherwise
   */
  static int
  xmlSwitchInputEncodingInt(xmlParserCtxtPtr ctxt, xmlParserInputPtr input,
                            xmlCharEncodingHandlerPtr handler, int len)
  {
      int nbchars;
  
      if (handler == NULL)
          return (-1);
      if (input == NULL)
          return (-1);
      if (input->buf != NULL) {
  	ctxt->charset = XML_CHAR_ENCODING_UTF8;
  
          if (input->buf->encoder != NULL) {
              /*
               * Check in case the auto encoding detection triggered
               * in already.
               */
              if (input->buf->encoder == handler)
                  return (0);
  
              /*
               * "UTF-16" can be used for both LE and BE
               if ((!xmlStrncmp(BAD_CAST input->buf->encoder->name,
               BAD_CAST "UTF-16", 6)) &&
               (!xmlStrncmp(BAD_CAST handler->name,
               BAD_CAST "UTF-16", 6))) {
               return(0);
               }
               */
  
              /*
               * Note: this is a bit dangerous, but that's what it
               * takes to use nearly compatible signature for different
               * encodings.
               *
               * FIXME: Encoders might buffer partial byte sequences, so
               * this probably can't work. We should return an error and
               * make sure that callers never try to switch the encoding
               * twice.
               */
              xmlCharEncCloseFunc(input->buf->encoder);
              input->buf->encoder = handler;
              return (0);
          }
          input->buf->encoder = handler;
  
          /*
           * Is there already some content down the pipe to convert ?
           */
          if (xmlBufIsEmpty(input->buf->buffer) == 0) {
              int processed;
  	    unsigned int use;
  
              /*
               * Specific handling of the Byte Order Mark for
               * UTF-16
               */
              if ((handler->name != NULL) &&
                  (!strcmp(handler->name, "UTF-16LE") ||
                   !strcmp(handler->name, "UTF-16")) &&
                  (input->cur[0] == 0xFF) && (input->cur[1] == 0xFE)) {
                  input->cur += 2;
              }
              if ((handler->name != NULL) &&
                  (!strcmp(handler->name, "UTF-16BE")) &&
                  (input->cur[0] == 0xFE) && (input->cur[1] == 0xFF)) {
                  input->cur += 2;
              }
              /*
               * Errata on XML-1.0 June 20 2001
               * Specific handling of the Byte Order Mark for
               * UTF-8
               */
              if ((handler->name != NULL) &&
                  (!strcmp(handler->name, "UTF-8")) &&
                  (input->cur[0] == 0xEF) &&
                  (input->cur[1] == 0xBB) && (input->cur[2] == 0xBF)) {
                  input->cur += 3;
              }
  
              /*
               * Shrink the current input buffer.
               * Move it as the raw buffer and create a new input buffer
               */
              processed = input->cur - input->base;
              xmlBufShrink(input->buf->buffer, processed);
              input->buf->raw = input->buf->buffer;
              input->buf->buffer = xmlBufCreate();
  	    input->buf->rawconsumed = processed;
  	    use = xmlBufUse(input->buf->raw);
  
              if (ctxt->html) {
                  /*
                   * convert as much as possible of the buffer
                   */
                  nbchars = xmlCharEncInput(input->buf, 1);
              } else {
                  /*
                   * convert just enough to get
                   * '<?xml version="1.0" encoding="xxx"?>'
                   * parsed with the autodetected encoding
                   * into the parser reading buffer.
                   */
                  nbchars = xmlCharEncFirstLineInput(input->buf, len);
              }
              xmlBufResetInput(input->buf->buffer, input);
              if (nbchars < 0) {
                  xmlErrInternal(ctxt,
                                 "switching encoding: encoder error\n",
                                 NULL);
                  return (-1);
              }
  	    input->buf->rawconsumed += use - xmlBufUse(input->buf->raw);
          }
          return (0);
      } else {
  	xmlErrInternal(ctxt,
                  "static memory buffer doesn't support encoding\n", NULL);
          /*
           * Callers assume that the input buffer takes ownership of the
           * encoding handler. xmlCharEncCloseFunc frees unregistered
           * handlers and avoids a memory leak.
           */
          xmlCharEncCloseFunc(handler);
  	return (-1);
      }
  }
  
  /**
   * xmlSwitchInputEncoding:
   * @ctxt:  the parser context
   * @input:  the input stream
   * @handler:  the encoding handler
   *
   * DEPRECATED: Use xmlSwitchToEncoding
   *
   * change the input functions when discovering the character encoding
   * of a given entity.
   *
   * Returns 0 in case of success, -1 otherwise
   */
  int
  xmlSwitchInputEncoding(xmlParserCtxtPtr ctxt, xmlParserInputPtr input,
                            xmlCharEncodingHandlerPtr handler) {
      return(xmlSwitchInputEncodingInt(ctxt, input, handler, -1));
  }
  
  /**
   * xmlSwitchToEncoding:
   * @ctxt:  the parser context
   * @handler:  the encoding handler
   *
   * change the input functions when discovering the character encoding
   * of a given entity.
   *
   * Returns 0 in case of success, -1 otherwise
   */
  int
  xmlSwitchToEncoding(xmlParserCtxtPtr ctxt, xmlCharEncodingHandlerPtr handler)
  {
      if (ctxt == NULL)
          return(-1);
      return(xmlSwitchInputEncodingInt(ctxt, ctxt->input, handler, -1));
  }
  
  /************************************************************************
   *									*
   *	Commodity functions to handle entities processing		*
   *									*
   ************************************************************************/
  
  /**
   * xmlFreeInputStream:
   * @input:  an xmlParserInputPtr
   *
   * Free up an input stream.
   */
  void
  xmlFreeInputStream(xmlParserInputPtr input) {
      if (input == NULL) return;
  
      if (input->filename != NULL) xmlFree((char *) input->filename);
      if (input->directory != NULL) xmlFree((char *) input->directory);
      if (input->encoding != NULL) xmlFree((char *) input->encoding);
      if (input->version != NULL) xmlFree((char *) input->version);
      if ((input->free != NULL) && (input->base != NULL))
          input->free((xmlChar *) input->base);
      if (input->buf != NULL)
          xmlFreeParserInputBuffer(input->buf);
      xmlFree(input);
  }
  
  /**
   * xmlNewInputStream:
   * @ctxt:  an XML parser context
   *
   * Create a new input stream structure.
   *
   * Returns the new input stream or NULL
   */
  xmlParserInputPtr
  xmlNewInputStream(xmlParserCtxtPtr ctxt) {
      xmlParserInputPtr input;
  
      input = (xmlParserInputPtr) xmlMalloc(sizeof(xmlParserInput));
      if (input == NULL) {
          xmlErrMemory(ctxt,  "couldn't allocate a new input stream\n");
  	return(NULL);
      }
      memset(input, 0, sizeof(xmlParserInput));
      input->line = 1;
      input->col = 1;
      input->standalone = -1;
  
      /*
       * If the context is NULL the id cannot be initialized, but that
       * should not happen while parsing which is the situation where
       * the id is actually needed.
       */
      if (ctxt != NULL)
          input->id = ctxt->input_id++;
  
      return(input);
  }
  
  /**
   * xmlNewIOInputStream:
   * @ctxt:  an XML parser context
   * @input:  an I/O Input
   * @enc:  the charset encoding if known
   *
   * Create a new input stream structure encapsulating the @input into
   * a stream suitable for the parser.
   *
   * Returns the new input stream or NULL
   */
  xmlParserInputPtr
  xmlNewIOInputStream(xmlParserCtxtPtr ctxt, xmlParserInputBufferPtr input,
  	            xmlCharEncoding enc) {
      xmlParserInputPtr inputStream;
  
      if (input == NULL) return(NULL);
      if (xmlParserDebugEntities)
  	xmlGenericError(xmlGenericErrorContext, "new input from I/O\n");
      inputStream = xmlNewInputStream(ctxt);
      if (inputStream == NULL) {
  	return(NULL);
      }
      inputStream->filename = NULL;
      inputStream->buf = input;
      xmlBufResetInput(inputStream->buf->buffer, inputStream);
  
      if (enc != XML_CHAR_ENCODING_NONE) {
          xmlSwitchEncoding(ctxt, enc);
      }
  
      return(inputStream);
  }
  
  /**
   * xmlNewEntityInputStream:
   * @ctxt:  an XML parser context
   * @entity:  an Entity pointer
   *
   * Create a new input stream based on an xmlEntityPtr
   *
   * Returns the new input stream or NULL
   */
  xmlParserInputPtr
  xmlNewEntityInputStream(xmlParserCtxtPtr ctxt, xmlEntityPtr entity) {
      xmlParserInputPtr input;
  
      if (entity == NULL) {
          xmlErrInternal(ctxt, "xmlNewEntityInputStream entity = NULL\n",
  	               NULL);
  	return(NULL);
      }
      if (xmlParserDebugEntities)
  	xmlGenericError(xmlGenericErrorContext,
  		"new input from entity: %s\n", entity->name);
      if (entity->content == NULL) {
  	switch (entity->etype) {
              case XML_EXTERNAL_GENERAL_UNPARSED_ENTITY:
  	        xmlErrInternal(ctxt, "Cannot parse entity %s\n",
  		               entity->name);
                  break;
              case XML_EXTERNAL_GENERAL_PARSED_ENTITY:
              case XML_EXTERNAL_PARAMETER_ENTITY:
  		return(xmlLoadExternalEntity((char *) entity->URI,
  		       (char *) entity->ExternalID, ctxt));
              case XML_INTERNAL_GENERAL_ENTITY:
  	        xmlErrInternal(ctxt,
  		      "Internal entity %s without content !\n",
  		               entity->name);
                  break;
              case XML_INTERNAL_PARAMETER_ENTITY:
  	        xmlErrInternal(ctxt,
  		      "Internal parameter entity %s without content !\n",
  		               entity->name);
                  break;
              case XML_INTERNAL_PREDEFINED_ENTITY:
  	        xmlErrInternal(ctxt,
  		      "Predefined entity %s without content !\n",
  		               entity->name);
                  break;
  	}
  	return(NULL);
      }
      input = xmlNewInputStream(ctxt);
      if (input == NULL) {
  	return(NULL);
      }
      if (entity->URI != NULL)
  	input->filename = (char *) xmlStrdup((xmlChar *) entity->URI);
      input->base = entity->content;
      if (entity->length == 0)
          entity->length = xmlStrlen(entity->content);
      input->cur = entity->content;
      input->length = entity->length;
      input->end = &entity->content[input->length];
      return(input);
  }
  
  /**
   * xmlNewStringInputStream:
   * @ctxt:  an XML parser context
   * @buffer:  an memory buffer
   *
   * Create a new input stream based on a memory buffer.
   * Returns the new input stream
   */
  xmlParserInputPtr
  xmlNewStringInputStream(xmlParserCtxtPtr ctxt, const xmlChar *buffer) {
      xmlParserInputPtr input;
  
      if (buffer == NULL) {
          xmlErrInternal(ctxt, "xmlNewStringInputStream string = NULL\n",
  	               NULL);
  	return(NULL);
      }
      if (xmlParserDebugEntities)
  	xmlGenericError(xmlGenericErrorContext,
  		"new fixed input: %.30s\n", buffer);
      input = xmlNewInputStream(ctxt);
      if (input == NULL) {
          xmlErrMemory(ctxt,  "couldn't allocate a new input stream\n");
  	return(NULL);
      }
      input->base = buffer;
      input->cur = buffer;
      input->length = xmlStrlen(buffer);
      input->end = &buffer[input->length];
      return(input);
  }
  
  /**
   * xmlNewInputFromFile:
   * @ctxt:  an XML parser context
   * @filename:  the filename to use as entity
   *
   * Create a new input stream based on a file or an URL.
   *
   * Returns the new input stream or NULL in case of error
   */
  xmlParserInputPtr
  xmlNewInputFromFile(xmlParserCtxtPtr ctxt, const char *filename) {
      xmlParserInputBufferPtr buf;
      xmlParserInputPtr inputStream;
      char *directory = NULL;
      xmlChar *URI = NULL;
  
      if (xmlParserDebugEntities)
  	xmlGenericError(xmlGenericErrorContext,
  		"new input from file: %s\n", filename);
      if (ctxt == NULL) return(NULL);
      buf = xmlParserInputBufferCreateFilename(filename, XML_CHAR_ENCODING_NONE);
      if (buf == NULL) {
  	if (filename == NULL)
  	    __xmlLoaderErr(ctxt,
  	                   "failed to load external entity: NULL filename \n",
  			   NULL);
  	else
  	    __xmlLoaderErr(ctxt, "failed to load external entity \"%s\"\n",
  			   (const char *) filename);
  	return(NULL);
      }
  
      inputStream = xmlNewInputStream(ctxt);
      if (inputStream == NULL) {
  	xmlFreeParserInputBuffer(buf);
  	return(NULL);
      }
  
      inputStream->buf = buf;
      inputStream = xmlCheckHTTPInput(ctxt, inputStream);
      if (inputStream == NULL)
          return(NULL);
  
      if (inputStream->filename == NULL)
  	URI = xmlStrdup((xmlChar *) filename);
      else
  	URI = xmlStrdup((xmlChar *) inputStream->filename);
      directory = xmlParserGetDirectory((const char *) URI);
      if (inputStream->filename != NULL) xmlFree((char *)inputStream->filename);
      inputStream->filename = (char *) xmlCanonicPath((const xmlChar *) URI);
      if (URI != NULL) xmlFree((char *) URI);
      inputStream->directory = directory;
  
      xmlBufResetInput(inputStream->buf->buffer, inputStream);
      if ((ctxt->directory == NULL) && (directory != NULL))
          ctxt->directory = (char *) xmlStrdup((const xmlChar *) directory);
      return(inputStream);
  }
  
  /************************************************************************
   *									*
   *		Commodity functions to handle parser contexts		*
   *									*
   ************************************************************************/
  
  /**
   * xmlInitParserCtxt:
   * @ctxt:  an XML parser context
   *
   * Initialize a parser context
   *
   * Returns 0 in case of success and -1 in case of error
   */
  
  int
  xmlInitParserCtxt(xmlParserCtxtPtr ctxt)
  {
      xmlParserInputPtr input;
  
      if(ctxt==NULL) {
          xmlErrInternal(NULL, "Got NULL parser context\n", NULL);
          return(-1);
      }
  
      xmlInitParser();
  
      if (ctxt->dict == NULL)
  	ctxt->dict = xmlDictCreate();
      if (ctxt->dict == NULL) {
          xmlErrMemory(NULL, "cannot initialize parser context\n");
  	return(-1);
      }
      xmlDictSetLimit(ctxt->dict, XML_MAX_DICTIONARY_LIMIT);
  
      if (ctxt->sax == NULL)
  	ctxt->sax = (xmlSAXHandler *) xmlMalloc(sizeof(xmlSAXHandler));
      if (ctxt->sax == NULL) {
          xmlErrMemory(NULL, "cannot initialize parser context\n");
  	return(-1);
      }
      else
          xmlSAXVersion(ctxt->sax, 2);
  
      ctxt->maxatts = 0;
      ctxt->atts = NULL;
      /* Allocate the Input stack */
      if (ctxt->inputTab == NULL) {
  	ctxt->inputTab = (xmlParserInputPtr *)
  		    xmlMalloc(5 * sizeof(xmlParserInputPtr));
  	ctxt->inputMax = 5;
      }
      if (ctxt->inputTab == NULL) {
          xmlErrMemory(NULL, "cannot initialize parser context\n");
  	ctxt->inputNr = 0;
  	ctxt->inputMax = 0;
  	ctxt->input = NULL;
  	return(-1);
      }
      while ((input = inputPop(ctxt)) != NULL) { /* Non consuming */
          xmlFreeInputStream(input);
      }
      ctxt->inputNr = 0;
      ctxt->input = NULL;
  
      ctxt->version = NULL;
      ctxt->encoding = NULL;
      ctxt->standalone = -1;
      ctxt->hasExternalSubset = 0;
      ctxt->hasPErefs = 0;
      ctxt->html = 0;
      ctxt->external = 0;
      ctxt->instate = XML_PARSER_START;
      ctxt->token = 0;
      ctxt->directory = NULL;
  
      /* Allocate the Node stack */
      if (ctxt->nodeTab == NULL) {
  	ctxt->nodeTab = (xmlNodePtr *) xmlMalloc(10 * sizeof(xmlNodePtr));
  	ctxt->nodeMax = 10;
      }
      if (ctxt->nodeTab == NULL) {
          xmlErrMemory(NULL, "cannot initialize parser context\n");
  	ctxt->nodeNr = 0;
  	ctxt->nodeMax = 0;
  	ctxt->node = NULL;
  	ctxt->inputNr = 0;
  	ctxt->inputMax = 0;
  	ctxt->input = NULL;
  	return(-1);
      }
      ctxt->nodeNr = 0;
      ctxt->node = NULL;
  
      /* Allocate the Name stack */
      if (ctxt->nameTab == NULL) {
  	ctxt->nameTab = (const xmlChar **) xmlMalloc(10 * sizeof(xmlChar *));
  	ctxt->nameMax = 10;
      }
      if (ctxt->nameTab == NULL) {
          xmlErrMemory(NULL, "cannot initialize parser context\n");
  	ctxt->nodeNr = 0;
  	ctxt->nodeMax = 0;
  	ctxt->node = NULL;
  	ctxt->inputNr = 0;
  	ctxt->inputMax = 0;
  	ctxt->input = NULL;
  	ctxt->nameNr = 0;
  	ctxt->nameMax = 0;
  	ctxt->name = NULL;
  	return(-1);
      }
      ctxt->nameNr = 0;
      ctxt->name = NULL;
  
      /* Allocate the space stack */
      if (ctxt->spaceTab == NULL) {
  	ctxt->spaceTab = (int *) xmlMalloc(10 * sizeof(int));
  	ctxt->spaceMax = 10;
      }
      if (ctxt->spaceTab == NULL) {
          xmlErrMemory(NULL, "cannot initialize parser context\n");
  	ctxt->nodeNr = 0;
  	ctxt->nodeMax = 0;
  	ctxt->node = NULL;
  	ctxt->inputNr = 0;
  	ctxt->inputMax = 0;
  	ctxt->input = NULL;
  	ctxt->nameNr = 0;
  	ctxt->nameMax = 0;
  	ctxt->name = NULL;
  	ctxt->spaceNr = 0;
  	ctxt->spaceMax = 0;
  	ctxt->space = NULL;
  	return(-1);
      }
      ctxt->spaceNr = 1;
      ctxt->spaceMax = 10;
      ctxt->spaceTab[0] = -1;
      ctxt->space = &ctxt->spaceTab[0];
      ctxt->userData = ctxt;
      ctxt->myDoc = NULL;
      ctxt->wellFormed = 1;
      ctxt->nsWellFormed = 1;
      ctxt->valid = 1;
      ctxt->loadsubset = xmlLoadExtDtdDefaultValue;
      if (ctxt->loadsubset) {
          ctxt->options |= XML_PARSE_DTDLOAD;
      }
      ctxt->validate = xmlDoValidityCheckingDefaultValue;
      ctxt->pedantic = xmlPedanticParserDefaultValue;
      if (ctxt->pedantic) {
          ctxt->options |= XML_PARSE_PEDANTIC;
      }
      ctxt->linenumbers = xmlLineNumbersDefaultValue;
      ctxt->keepBlanks = xmlKeepBlanksDefaultValue;
      if (ctxt->keepBlanks == 0) {
  	ctxt->sax->ignorableWhitespace = xmlSAX2IgnorableWhitespace;
  	ctxt->options |= XML_PARSE_NOBLANKS;
      }
  
      ctxt->vctxt.flags = XML_VCTXT_USE_PCTXT;
      ctxt->vctxt.userData = ctxt;
      ctxt->vctxt.error = xmlParserValidityError;
      ctxt->vctxt.warning = xmlParserValidityWarning;
      if (ctxt->validate) {
  	if (xmlGetWarningsDefaultValue == 0)
  	    ctxt->vctxt.warning = NULL;
  	else
  	    ctxt->vctxt.warning = xmlParserValidityWarning;
  	ctxt->vctxt.nodeMax = 0;
          ctxt->options |= XML_PARSE_DTDVALID;
      }
      ctxt->replaceEntities = xmlSubstituteEntitiesDefaultValue;
      if (ctxt->replaceEntities) {
          ctxt->options |= XML_PARSE_NOENT;
      }
      ctxt->record_info = 0;
      ctxt->checkIndex = 0;
      ctxt->inSubset = 0;
      ctxt->errNo = XML_ERR_OK;
      ctxt->depth = 0;
      ctxt->charset = XML_CHAR_ENCODING_UTF8;
      ctxt->catalogs = NULL;
      ctxt->nbentities = 0;
      ctxt->sizeentities = 0;
      ctxt->sizeentcopy = 0;
      ctxt->input_id = 1;
      xmlInitNodeInfoSeq(&ctxt->node_seq);
      return(0);
  }
  
  /**
   * xmlFreeParserCtxt:
   * @ctxt:  an XML parser context
   *
   * Free all the memory used by a parser context. However the parsed
   * document in ctxt->myDoc is not freed.
   */
  
  void
  xmlFreeParserCtxt(xmlParserCtxtPtr ctxt)
  {
      xmlParserInputPtr input;
  
      if (ctxt == NULL) return;
  
      while ((input = inputPop(ctxt)) != NULL) { /* Non consuming */
          xmlFreeInputStream(input);
      }
      if (ctxt->spaceTab != NULL) xmlFree(ctxt->spaceTab);
      if (ctxt->nameTab != NULL) xmlFree((xmlChar * *)ctxt->nameTab);
      if (ctxt->nodeTab != NULL) xmlFree(ctxt->nodeTab);
      if (ctxt->nodeInfoTab != NULL) xmlFree(ctxt->nodeInfoTab);
      if (ctxt->inputTab != NULL) xmlFree(ctxt->inputTab);
      if (ctxt->version != NULL) xmlFree((char *) ctxt->version);
      if (ctxt->encoding != NULL) xmlFree((char *) ctxt->encoding);
      if (ctxt->extSubURI != NULL) xmlFree((char *) ctxt->extSubURI);
      if (ctxt->extSubSystem != NULL) xmlFree((char *) ctxt->extSubSystem);
  #ifdef LIBXML_SAX1_ENABLED
      if ((ctxt->sax != NULL) &&
          (ctxt->sax != (xmlSAXHandlerPtr) &xmlDefaultSAXHandler))
  #else
      if (ctxt->sax != NULL)
  #endif /* LIBXML_SAX1_ENABLED */
          xmlFree(ctxt->sax);
      if (ctxt->directory != NULL) xmlFree((char *) ctxt->directory);
      if (ctxt->vctxt.nodeTab != NULL) xmlFree(ctxt->vctxt.nodeTab);
      if (ctxt->atts != NULL) xmlFree((xmlChar * *)ctxt->atts);
      if (ctxt->dict != NULL) xmlDictFree(ctxt->dict);
      if (ctxt->nsTab != NULL) xmlFree((char *) ctxt->nsTab);
      if (ctxt->pushTab != NULL) xmlFree(ctxt->pushTab);
      if (ctxt->attallocs != NULL) xmlFree(ctxt->attallocs);
      if (ctxt->attsDefault != NULL)
          xmlHashFree(ctxt->attsDefault, xmlHashDefaultDeallocator);
      if (ctxt->attsSpecial != NULL)
          xmlHashFree(ctxt->attsSpecial, NULL);
      if (ctxt->freeElems != NULL) {
          xmlNodePtr cur, next;
  
  	cur = ctxt->freeElems;
  	while (cur != NULL) {
  	    next = cur->next;
  	    xmlFree(cur);
  	    cur = next;
  	}
      }
      if (ctxt->freeAttrs != NULL) {
          xmlAttrPtr cur, next;
  
  	cur = ctxt->freeAttrs;
  	while (cur != NULL) {
  	    next = cur->next;
  	    xmlFree(cur);
  	    cur = next;
  	}
      }
      /*
       * cleanup the error strings
       */
      if (ctxt->lastError.message != NULL)
          xmlFree(ctxt->lastError.message);
      if (ctxt->lastError.file != NULL)
          xmlFree(ctxt->lastError.file);
      if (ctxt->lastError.str1 != NULL)
          xmlFree(ctxt->lastError.str1);
      if (ctxt->lastError.str2 != NULL)
          xmlFree(ctxt->lastError.str2);
      if (ctxt->lastError.str3 != NULL)
          xmlFree(ctxt->lastError.str3);
  
  #ifdef LIBXML_CATALOG_ENABLED
      if (ctxt->catalogs != NULL)
  	xmlCatalogFreeLocal(ctxt->catalogs);
  #endif
      xmlFree(ctxt);
  }
  
  /**
   * xmlNewParserCtxt:
   *
   * Allocate and initialize a new parser context.
   *
   * Returns the xmlParserCtxtPtr or NULL
   */
  
  xmlParserCtxtPtr
  xmlNewParserCtxt(void)
  {
      xmlParserCtxtPtr ctxt;
  
      ctxt = (xmlParserCtxtPtr) xmlMalloc(sizeof(xmlParserCtxt));
      if (ctxt == NULL) {
  	xmlErrMemory(NULL, "cannot allocate parser context\n");
  	return(NULL);
      }
      memset(ctxt, 0, sizeof(xmlParserCtxt));
      if (xmlInitParserCtxt(ctxt) < 0) {
          xmlFreeParserCtxt(ctxt);
  	return(NULL);
      }
      return(ctxt);
  }
  
  /************************************************************************
   *									*
   *		Handling of node information				*
   *									*
   ************************************************************************/
  
  /**
   * xmlClearParserCtxt:
   * @ctxt:  an XML parser context
   *
   * Clear (release owned resources) and reinitialize a parser context
   */
  
  void
  xmlClearParserCtxt(xmlParserCtxtPtr ctxt)
  {
    if (ctxt==NULL)
      return;
    xmlClearNodeInfoSeq(&ctxt->node_seq);
    xmlCtxtReset(ctxt);
  }
  
  
  /**
   * xmlParserFindNodeInfo:
   * @ctx:  an XML parser context
   * @node:  an XML node within the tree
   *
   * Find the parser node info struct for a given node
   *
   * Returns an xmlParserNodeInfo block pointer or NULL
   */
  const xmlParserNodeInfo *
  xmlParserFindNodeInfo(const xmlParserCtxtPtr ctx, const xmlNodePtr node)
  {
      unsigned long pos;
  
      if ((ctx == NULL) || (node == NULL))
          return (NULL);
      /* Find position where node should be at */
      pos = xmlParserFindNodeInfoIndex(&ctx->node_seq, node);
      if (pos < ctx->node_seq.length
          && ctx->node_seq.buffer[pos].node == node)
          return &ctx->node_seq.buffer[pos];
      else
          return NULL;
  }
  
  
  /**
   * xmlInitNodeInfoSeq:
   * @seq:  a node info sequence pointer
   *
   * -- Initialize (set to initial state) node info sequence
   */
  void
  xmlInitNodeInfoSeq(xmlParserNodeInfoSeqPtr seq)
  {
      if (seq == NULL)
          return;
      seq->length = 0;
      seq->maximum = 0;
      seq->buffer = NULL;
  }
  
  /**
   * xmlClearNodeInfoSeq:
   * @seq:  a node info sequence pointer
   *
   * -- Clear (release memory and reinitialize) node
   *   info sequence
   */
  void
  xmlClearNodeInfoSeq(xmlParserNodeInfoSeqPtr seq)
  {
      if (seq == NULL)
          return;
      if (seq->buffer != NULL)
          xmlFree(seq->buffer);
      xmlInitNodeInfoSeq(seq);
  }
  
  /**
   * xmlParserFindNodeInfoIndex:
   * @seq:  a node info sequence pointer
   * @node:  an XML node pointer
   *
   *
   * xmlParserFindNodeInfoIndex : Find the index that the info record for
   *   the given node is or should be at in a sorted sequence
   *
   * Returns a long indicating the position of the record
   */
  unsigned long
  xmlParserFindNodeInfoIndex(const xmlParserNodeInfoSeqPtr seq,
                             const xmlNodePtr node)
  {
      unsigned long upper, lower, middle;
      int found = 0;
  
      if ((seq == NULL) || (node == NULL))
          return ((unsigned long) -1);
  
      /* Do a binary search for the key */
      lower = 1;
      upper = seq->length;
      middle = 0;
      while (lower <= upper && !found) {
          middle = lower + (upper - lower) / 2;
          if (node == seq->buffer[middle - 1].node)
              found = 1;
          else if (node < seq->buffer[middle - 1].node)
              upper = middle - 1;
          else
              lower = middle + 1;
      }
  
      /* Return position */
      if (middle == 0 || seq->buffer[middle - 1].node < node)
          return middle;
      else
          return middle - 1;
  }
  
  
  /**
   * xmlParserAddNodeInfo:
   * @ctxt:  an XML parser context
   * @info:  a node info sequence pointer
   *
   * Insert node info record into the sorted sequence
   */
  void
  xmlParserAddNodeInfo(xmlParserCtxtPtr ctxt,
                       const xmlParserNodeInfoPtr info)
  {
      unsigned long pos;
  
      if ((ctxt == NULL) || (info == NULL)) return;
  
      /* Find pos and check to see if node is already in the sequence */
      pos = xmlParserFindNodeInfoIndex(&ctxt->node_seq, (xmlNodePtr)
                                       info->node);
  
      if ((pos < ctxt->node_seq.length) &&
          (ctxt->node_seq.buffer != NULL) &&
          (ctxt->node_seq.buffer[pos].node == info->node)) {
          ctxt->node_seq.buffer[pos] = *info;
      }
  
      /* Otherwise, we need to add new node to buffer */
      else {
          if ((ctxt->node_seq.length + 1 > ctxt->node_seq.maximum) ||
  	    (ctxt->node_seq.buffer == NULL)) {
              xmlParserNodeInfo *tmp_buffer;
              unsigned int byte_size;
  
              if (ctxt->node_seq.maximum == 0)
                  ctxt->node_seq.maximum = 2;
              byte_size = (sizeof(*ctxt->node_seq.buffer) *
  			(2 * ctxt->node_seq.maximum));
  
              if (ctxt->node_seq.buffer == NULL)
                  tmp_buffer = (xmlParserNodeInfo *) xmlMalloc(byte_size);
              else
                  tmp_buffer =
                      (xmlParserNodeInfo *) xmlRealloc(ctxt->node_seq.buffer,
                                                       byte_size);
  
              if (tmp_buffer == NULL) {
  		xmlErrMemory(ctxt, "failed to allocate buffer\n");
                  return;
              }
              ctxt->node_seq.buffer = tmp_buffer;
              ctxt->node_seq.maximum *= 2;
          }
  
          /* If position is not at end, move elements out of the way */
          if (pos != ctxt->node_seq.length) {
              unsigned long i;
  
              for (i = ctxt->node_seq.length; i > pos; i--)
                  ctxt->node_seq.buffer[i] = ctxt->node_seq.buffer[i - 1];
          }
  
          /* Copy element and increase length */
          ctxt->node_seq.buffer[pos] = *info;
          ctxt->node_seq.length++;
      }
  }
  
  /************************************************************************
   *									*
   *		Defaults settings					*
   *									*
   ************************************************************************/
  /**
   * xmlPedanticParserDefault:
   * @val:  int 0 or 1
   *
   * Set and return the previous value for enabling pedantic warnings.
   *
   * Returns the last value for 0 for no substitution, 1 for substitution.
   */
  
  int
  xmlPedanticParserDefault(int val) {
      int old = xmlPedanticParserDefaultValue;
  
      xmlPedanticParserDefaultValue = val;
      return(old);
  }
  
  /**
   * xmlLineNumbersDefault:
   * @val:  int 0 or 1
   *
   * Set and return the previous value for enabling line numbers in elements
   * contents. This may break on old application and is turned off by default.
   *
   * Returns the last value for 0 for no substitution, 1 for substitution.
   */
  
  int
  xmlLineNumbersDefault(int val) {
      int old = xmlLineNumbersDefaultValue;
  
      xmlLineNumbersDefaultValue = val;
      return(old);
  }
  
  /**
   * xmlSubstituteEntitiesDefault:
   * @val:  int 0 or 1
   *
   * Set and return the previous value for default entity support.
   * Initially the parser always keep entity references instead of substituting
   * entity values in the output. This function has to be used to change the
   * default parser behavior
   * SAX::substituteEntities() has to be used for changing that on a file by
   * file basis.
   *
   * Returns the last value for 0 for no substitution, 1 for substitution.
   */
  
  int
  xmlSubstituteEntitiesDefault(int val) {
      int old = xmlSubstituteEntitiesDefaultValue;
  
      xmlSubstituteEntitiesDefaultValue = val;
      return(old);
  }
  
  /**
   * xmlKeepBlanksDefault:
   * @val:  int 0 or 1
   *
   * Set and return the previous value for default blanks text nodes support.
   * The 1.x version of the parser used an heuristic to try to detect
   * ignorable white spaces. As a result the SAX callback was generating
   * xmlSAX2IgnorableWhitespace() callbacks instead of characters() one, and when
   * using the DOM output text nodes containing those blanks were not generated.
   * The 2.x and later version will switch to the XML standard way and
   * ignorableWhitespace() are only generated when running the parser in
   * validating mode and when the current element doesn't allow CDATA or
   * mixed content.
   * This function is provided as a way to force the standard behavior
   * on 1.X libs and to switch back to the old mode for compatibility when
   * running 1.X client code on 2.X . Upgrade of 1.X code should be done
   * by using xmlIsBlankNode() commodity function to detect the "empty"
   * nodes generated.
   * This value also affect autogeneration of indentation when saving code
   * if blanks sections are kept, indentation is not generated.
   *
   * Returns the last value for 0 for no substitution, 1 for substitution.
   */
  
  int
  xmlKeepBlanksDefault(int val) {
      int old = xmlKeepBlanksDefaultValue;
  
      xmlKeepBlanksDefaultValue = val;
      if (!val) xmlIndentTreeOutput = 1;
      return(old);
  }
  
  

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