/*

 * string.c : an XML string utilities module

 *

 * This module provides various utility functions for manipulating

 * the xmlChar* type. All functions named xmlStr* have been moved here

 * from the parser.c file (their original home). 

 *

 * See Copyright for the status of this software.

 *

 * UTF8 string routines from:

 * William Brack <wbrack@mmm.com.hk>

 *

 * daniel@veillard.com

 */

#define IN_LIBXML

#include "libxml.h"

#include <stdlib.h>

#include <string.h>

#include <libxml/xmlmemory.h>

#include <libxml/parserInternals.h>

#include <libxml/xmlstring.h>

/************************************************************************

 *                                                                      *

 *                Commodity functions to handle xmlChars                *

 *                                                                      *

 ************************************************************************/

/**

 * xmlStrndup:

 * @cur:  the input xmlChar *

 * @len:  the len of @cur

 *

 * a strndup for array of xmlChar's

 *

 * Returns a new xmlChar * or NULL

 */

xmlChar *

xmlStrndup(const xmlChar *cur, int len) {

    xmlChar *ret;

    if ((cur == NULL) || (len < 0)) return(NULL);

    ret = (xmlChar *) xmlMallocAtomic((len + 1) * sizeof(xmlChar));

    if (ret == NULL) {

        xmlErrMemory(NULL, NULL);

        return(NULL);

    }

    memcpy(ret, cur, len * sizeof(xmlChar));

    ret[len] = 0;

    return(ret);

}

/**

 * xmlStrdup:

 * @cur:  the input xmlChar *

 *

 * a strdup for array of xmlChar's. Since they are supposed to be

 * encoded in UTF-8 or an encoding with 8bit based chars, we assume

 * a termination mark of '0'.

 *

 * Returns a new xmlChar * or NULL

 */

xmlChar *

xmlStrdup(const xmlChar *cur) {

    const xmlChar *p = cur;

    if (cur == NULL) return(NULL);

    while (*p != 0) p++; /* non input consuming */

    return(xmlStrndup(cur, p - cur));

}

/**

 * xmlCharStrndup:

 * @cur:  the input char *

 * @len:  the len of @cur

 *

 * a strndup for char's to xmlChar's

 *

 * Returns a new xmlChar * or NULL

 */

xmlChar *

xmlCharStrndup(const char *cur, int len) {

    int i;

    xmlChar *ret;

    if ((cur == NULL) || (len < 0)) return(NULL);

    ret = (xmlChar *) xmlMallocAtomic((len + 1) * sizeof(xmlChar));

    if (ret == NULL) {

        xmlErrMemory(NULL, NULL);

        return(NULL);

    }

    for (i = 0;i < len;i++) {

        ret[i] = (xmlChar) cur[i];

        if (ret[i] == 0) return(ret);

    }

    ret[len] = 0;

    return(ret);

}

/**

 * xmlCharStrdup:

 * @cur:  the input char *

 *

 * a strdup for char's to xmlChar's

 *

 * Returns a new xmlChar * or NULL

 */

xmlChar *

xmlCharStrdup(const char *cur) {

    const char *p = cur;

    if (cur == NULL) return(NULL);

    while (*p != '\0') p++; /* non input consuming */

    return(xmlCharStrndup(cur, p - cur));

}

/**

 * xmlStrcmp:

 * @str1:  the first xmlChar *

 * @str2:  the second xmlChar *

 *

 * a strcmp for xmlChar's

 *

 * Returns the integer result of the comparison

 */

int

xmlStrcmp(const xmlChar *str1, const xmlChar *str2) {

    register int tmp;

    if (str1 == str2) return(0);

    if (str1 == NULL) return(-1);

    if (str2 == NULL) return(1);

    do {

        tmp = *str1++ - *str2;

        if (tmp != 0) return(tmp);

    } while (*str2++ != 0);

    return 0;

}

/**

 * xmlStrEqual:

 * @str1:  the first xmlChar *

 * @str2:  the second xmlChar *

 *

 * Check if both strings are equal of have same content.

 * Should be a bit more readable and faster than xmlStrcmp()

 *

 * Returns 1 if they are equal, 0 if they are different

 */

int

xmlStrEqual(const xmlChar *str1, const xmlChar *str2) {

    if (str1 == str2) return(1);

    if (str1 == NULL) return(0);

    if (str2 == NULL) return(0);

    do {

        if (*str1++ != *str2) return(0);

    } while (*str2++);

    return(1);

}

/**

 * xmlStrQEqual:

 * @pref:  the prefix of the QName

 * @name:  the localname of the QName

 * @str:  the second xmlChar *

 *

 * Check if a QName is Equal to a given string 

 *

 * Returns 1 if they are equal, 0 if they are different

 */

int

xmlStrQEqual(const xmlChar *pref, const xmlChar *name, const xmlChar *str) {

    if (pref == NULL) return(xmlStrEqual(name, str));

    if (name == NULL) return(0);

    if (str == NULL) return(0);

    do {

        if (*pref++ != *str) return(0);

    } while ((*str++) && (*pref));

    if (*str++ != ':') return(0);

    do {

        if (*name++ != *str) return(0);

    } while (*str++);

    return(1);

}

/**

 * xmlStrncmp:

 * @str1:  the first xmlChar *

 * @str2:  the second xmlChar *

 * @len:  the max comparison length

 *

 * a strncmp for xmlChar's

 *

 * Returns the integer result of the comparison

 */

int

xmlStrncmp(const xmlChar *str1, const xmlChar *str2, int len) {

    register int tmp;

    if (len <= 0) return(0);

    if (str1 == str2) return(0);

    if (str1 == NULL) return(-1);

    if (str2 == NULL) return(1);

#ifdef __GNUC__

    tmp = strncmp((const char *)str1, (const char *)str2, len);

    return tmp;

#else

    do {

        tmp = *str1++ - *str2;

        if (tmp != 0 || --len == 0) return(tmp);

    } while (*str2++ != 0);

    return 0;

#endif

}

static const xmlChar casemap[256] = {

    0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,

    0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,

    0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,

    0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,

    0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,

    0x28,0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F,

    0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,

    0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,

    0x40,0x61,0x62,0x63,0x64,0x65,0x66,0x67,

    0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,

    0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,

    0x78,0x79,0x7A,0x7B,0x5C,0x5D,0x5E,0x5F,

    0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,

    0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,

    0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,

    0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x7F,

    0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,

    0x88,0x89,0x8A,0x8B,0x8C,0x8D,0x8E,0x8F,

    0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,

    0x98,0x99,0x9A,0x9B,0x9C,0x9D,0x9E,0x9F,

    0xA0,0xA1,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,

    0xA8,0xA9,0xAA,0xAB,0xAC,0xAD,0xAE,0xAF,

    0xB0,0xB1,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,

    0xB8,0xB9,0xBA,0xBB,0xBC,0xBD,0xBE,0xBF,

    0xC0,0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,

    0xC8,0xC9,0xCA,0xCB,0xCC,0xCD,0xCE,0xCF,

    0xD0,0xD1,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,

    0xD8,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,

    0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,

    0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,

    0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,

    0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF

};

/**

 * xmlStrcasecmp:

 * @str1:  the first xmlChar *

 * @str2:  the second xmlChar *

 *

 * a strcasecmp for xmlChar's

 *

 * Returns the integer result of the comparison

 */

int

xmlStrcasecmp(const xmlChar *str1, const xmlChar *str2) {

    register int tmp;

    if (str1 == str2) return(0);

    if (str1 == NULL) return(-1);

    if (str2 == NULL) return(1);

    do {

        tmp = casemap[*str1++] - casemap[*str2];

        if (tmp != 0) return(tmp);

    } while (*str2++ != 0);

    return 0;

}

/**

 * xmlStrncasecmp:

 * @str1:  the first xmlChar *

 * @str2:  the second xmlChar *

 * @len:  the max comparison length

 *

 * a strncasecmp for xmlChar's

 *

 * Returns the integer result of the comparison

 */

int

xmlStrncasecmp(const xmlChar *str1, const xmlChar *str2, int len) {

    register int tmp;

    if (len <= 0) return(0);

    if (str1 == str2) return(0);

    if (str1 == NULL) return(-1);

    if (str2 == NULL) return(1);

    do {

        tmp = casemap[*str1++] - casemap[*str2];

        if (tmp != 0 || --len == 0) return(tmp);

    } while (*str2++ != 0);

    return 0;

}

/**

 * xmlStrchr:

 * @str:  the xmlChar * array

 * @val:  the xmlChar to search

 *

 * a strchr for xmlChar's

 *

 * Returns the xmlChar * for the first occurrence or NULL.

 */

const xmlChar *

xmlStrchr(const xmlChar *str, xmlChar val) {

    if (str == NULL) return(NULL);

    while (*str != 0) { /* non input consuming */

        if (*str == val) return((xmlChar *) str);

        str++;

    }

    return(NULL);

}

/**

 * xmlStrstr:

 * @str:  the xmlChar * array (haystack)

 * @val:  the xmlChar to search (needle)

 *

 * a strstr for xmlChar's

 *

 * Returns the xmlChar * for the first occurrence or NULL.

 */

const xmlChar *

xmlStrstr(const xmlChar *str, const xmlChar *val) {

    int n;

    if (str == NULL) return(NULL);

    if (val == NULL) return(NULL);

    n = xmlStrlen(val);

    if (n == 0) return(str);

    while (*str != 0) { /* non input consuming */

        if (*str == *val) {

            if (!xmlStrncmp(str, val, n)) return((const xmlChar *) str);

        }

        str++;

    }

    return(NULL);

}

/**

 * xmlStrcasestr:

 * @str:  the xmlChar * array (haystack)

 * @val:  the xmlChar to search (needle)

 *

 * a case-ignoring strstr for xmlChar's

 *

 * Returns the xmlChar * for the first occurrence or NULL.

 */

const xmlChar *

xmlStrcasestr(const xmlChar *str, xmlChar *val) {

    int n;

    if (str == NULL) return(NULL);

    if (val == NULL) return(NULL);

    n = xmlStrlen(val);

    if (n == 0) return(str);

    while (*str != 0) { /* non input consuming */

        if (casemap[*str] == casemap[*val])

            if (!xmlStrncasecmp(str, val, n)) return(str);

        str++;

    }

    return(NULL);

}

/**

 * xmlStrsub:

 * @str:  the xmlChar * array (haystack)

 * @start:  the index of the first char (zero based)

 * @len:  the length of the substring

 *

 * Extract a substring of a given string

 *

 * Returns the xmlChar * for the first occurrence or NULL.

 */

xmlChar *

xmlStrsub(const xmlChar *str, int start, int len) {

    int i;

    if (str == NULL) return(NULL);

    if (start < 0) return(NULL);

    if (len < 0) return(NULL);

    for (i = 0;i < start;i++) {

        if (*str == 0) return(NULL);

        str++;

    }

    if (*str == 0) return(NULL);

    return(xmlStrndup(str, len));

}

/**

 * xmlStrlen:

 * @str:  the xmlChar * array

 *

 * length of a xmlChar's string

 *

 * Returns the number of xmlChar contained in the ARRAY.

 */

int

xmlStrlen(const xmlChar *str) {

    int len = 0;

    if (str == NULL) return(0);

    while (*str != 0) { /* non input consuming */

        str++;

        len++;

    }

    return(len);

}

/**

 * xmlStrncat:

 * @cur:  the original xmlChar * array

 * @add:  the xmlChar * array added

 * @len:  the length of @add

 *

 * a strncat for array of xmlChar's, it will extend @cur with the len

 * first bytes of @add. Note that if @len < 0 then this is an API error

 * and NULL will be returned.

 *

 * Returns a new xmlChar *, the original @cur is reallocated if needed

 * and should not be freed

 */

xmlChar *

xmlStrncat(xmlChar *cur, const xmlChar *add, int len) {

    int size;

    xmlChar *ret;

    if ((add == NULL) || (len == 0))

        return(cur);

    if (len < 0)

	return(NULL);

    if (cur == NULL)

        return(xmlStrndup(add, len));

    size = xmlStrlen(cur);

    ret = (xmlChar *) xmlRealloc(cur, (size + len + 1) * sizeof(xmlChar));

    if (ret == NULL) {

        xmlErrMemory(NULL, NULL);

        return(cur);

    }

    memcpy(&ret[size], add, len * sizeof(xmlChar));

    ret[size + len] = 0;

    return(ret);

}

/**

 * xmlStrncatNew:

 * @str1:  first xmlChar string

 * @str2:  second xmlChar string

 * @len:  the len of @str2 or < 0

 *

 * same as xmlStrncat, but creates a new string.  The original

 * two strings are not freed. If @len is < 0 then the length

 * will be calculated automatically.

 *

 * Returns a new xmlChar * or NULL

 */

xmlChar *

xmlStrncatNew(const xmlChar *str1, const xmlChar *str2, int len) {

    int size;

    xmlChar *ret;

    if (len < 0)

        len = xmlStrlen(str2);

    if ((str2 == NULL) || (len == 0))

        return(xmlStrdup(str1));

    if (str1 == NULL)

        return(xmlStrndup(str2, len));

    size = xmlStrlen(str1);

    ret = (xmlChar *) xmlMalloc((size + len + 1) * sizeof(xmlChar));

    if (ret == NULL) {

        xmlErrMemory(NULL, NULL);

        return(xmlStrndup(str1, size));

    }

    memcpy(ret, str1, size * sizeof(xmlChar));

    memcpy(&ret[size], str2, len * sizeof(xmlChar));

    ret[size + len] = 0;

    return(ret);

}

/**

 * xmlStrcat:

 * @cur:  the original xmlChar * array

 * @add:  the xmlChar * array added

 *

 * a strcat for array of xmlChar's. Since they are supposed to be

 * encoded in UTF-8 or an encoding with 8bit based chars, we assume

 * a termination mark of '0'.

 *

 * Returns a new xmlChar * containing the concatenated string.

 */

xmlChar *

xmlStrcat(xmlChar *cur, const xmlChar *add) {

    const xmlChar *p = add;

    if (add == NULL) return(cur);

    if (cur == NULL) 

        return(xmlStrdup(add));

    while (*p != 0) p++; /* non input consuming */

    return(xmlStrncat(cur, add, p - add));

}

/**

 * xmlStrPrintf:

 * @buf:   the result buffer.

 * @len:   the result buffer length.

 * @msg:   the message with printf formatting.

 * @...:   extra parameters for the message.

 *

 * Formats @msg and places result into @buf.

 *

 * Returns the number of characters written to @buf or -1 if an error occurs.

 */

int XMLCDECL 

xmlStrPrintf(xmlChar *buf, int len, const xmlChar *msg, ...) {

    va_list args;

    int ret;

    if((buf == NULL) || (msg == NULL)) {

        return(-1);

    }

    va_start(args, msg);

    ret = vsnprintf((char *) buf, len, (const char *) msg, args);

    va_end(args);

    buf[len - 1] = 0; /* be safe ! */

    return(ret);

}

/**

 * xmlStrVPrintf:

 * @buf:   the result buffer.

 * @len:   the result buffer length.

 * @msg:   the message with printf formatting.

 * @ap:    extra parameters for the message.

 *

 * Formats @msg and places result into @buf.

 *

 * Returns the number of characters written to @buf or -1 if an error occurs.

 */

int 

xmlStrVPrintf(xmlChar *buf, int len, const xmlChar *msg, va_list ap) {

    int ret;

    if((buf == NULL) || (msg == NULL)) {

        return(-1);

    }

    ret = vsnprintf((char *) buf, len, (const char *) msg, ap);

    buf[len - 1] = 0; /* be safe ! */

    return(ret);

}

/************************************************************************

 *                                                                      *

 *              Generic UTF8 handling routines                          *

 *                                                                      *

 * 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                     *

 *                                                                      *

 * I hope we won't use values > 0xFFFF anytime soon !                   *

 *                                                                      *

 ************************************************************************/

/**

 * xmlUTF8Size:

 * @utf: pointer to the UTF8 character

 *

 * calculates the internal size of a UTF8 character

 *

 * returns the numbers of bytes in the character, -1 on format error

 */

int

xmlUTF8Size(const xmlChar *utf) {

    xmlChar mask;

    int len;

    if (utf == NULL)

        return -1;

    if (*utf < 0x80)

        return 1;

    /* check valid UTF8 character */

    if (!(*utf & 0x40))

        return -1;

    /* determine number of bytes in char */

    len = 2;

    for (mask=0x20; mask != 0; mask>>=1) {

        if (!(*utf & mask))

            return len;

        len++;

    }

    return -1;

}

/**

 * xmlUTF8Charcmp:

 * @utf1: pointer to first UTF8 char

 * @utf2: pointer to second UTF8 char

 *

 * compares the two UCS4 values

 *

 * returns result of the compare as with xmlStrncmp

 */

int

xmlUTF8Charcmp(const xmlChar *utf1, const xmlChar *utf2) {

    if (utf1 == NULL ) {

        if (utf2 == NULL)

            return 0;

        return -1;

    }

    return xmlStrncmp(utf1, utf2, xmlUTF8Size(utf1));

}

/**

 * xmlUTF8Strlen:

 * @utf:  a sequence of UTF-8 encoded bytes

 *

 * compute the length of an UTF8 string, it doesn't do a full UTF8

 * checking of the content of the string.

 *

 * Returns the number of characters in the string or -1 in case of error

 */

int

xmlUTF8Strlen(const xmlChar *utf) {

    int ret = 0;

    if (utf == NULL)

        return(-1);

    while (*utf != 0) {

        if (utf[0] & 0x80) {

            if ((utf[1] & 0xc0) != 0x80)

                return(-1);

            if ((utf[0] & 0xe0) == 0xe0) {

                if ((utf[2] & 0xc0) != 0x80)

                    return(-1);

                if ((utf[0] & 0xf0) == 0xf0) {

                    if ((utf[0] & 0xf8) != 0xf0 || (utf[3] & 0xc0) != 0x80)

                        return(-1);

                    utf += 4;

                } else {

                    utf += 3;

                }

            } else {

                utf += 2;

            }

        } else {

            utf++;

        }

        ret++;

    }

    return(ret);

}

/**

 * xmlGetUTF8Char:

 * @utf:  a sequence of UTF-8 encoded bytes

 * @len:  a pointer to the minimum number of bytes present in

 *        the sequence.  This is used to assure the next character

 *        is completely contained within the sequence.

 *

 * Read the first UTF8 character from @utf

 *

 * Returns the char value or -1 in case of error, and sets *len to

 *        the actual number of bytes consumed (0 in case of error)

 */

int

xmlGetUTF8Char(const unsigned char *utf, int *len) {

    unsigned int c;

    if (utf == NULL)

        goto error;

    if (len == NULL)

        goto error;

    if (*len < 1)

        goto error;

    c = utf[0];

    if (c & 0x80) {

        if (*len < 2)

            goto error;

        if ((utf[1] & 0xc0) != 0x80)

            goto error;

        if ((c & 0xe0) == 0xe0) {

            if (*len < 3)

                goto error;

            if ((utf[2] & 0xc0) != 0x80)

                goto error;

            if ((c & 0xf0) == 0xf0) {

                if (*len < 4)

                    goto error;

                if ((c & 0xf8) != 0xf0 || (utf[3] & 0xc0) != 0x80)

                    goto error;

                *len = 4;

                /* 4-byte code */

                c = (utf[0] & 0x7) << 18;

                c |= (utf[1] & 0x3f) << 12;

                c |= (utf[2] & 0x3f) << 6;

                c |= utf[3] & 0x3f;

            } else {

              /* 3-byte code */

                *len = 3;

                c = (utf[0] & 0xf) << 12;

                c |= (utf[1] & 0x3f) << 6;

                c |= utf[2] & 0x3f;

            }

        } else {

          /* 2-byte code */

            *len = 2;

            c = (utf[0] & 0x1f) << 6;

            c |= utf[1] & 0x3f;

        }

    } else {

        /* 1-byte code */

        *len = 1;

    }

    return(c);

error:

    if (len != NULL)

	*len = 0;

    return(-1);

}

/**

 * xmlCheckUTF8:

 * @utf: Pointer to putative UTF-8 encoded string.

 *

 * Checks @utf for being valid UTF-8. @utf is assumed to be

 * null-terminated. This function is not super-strict, as it will

 * allow longer UTF-8 sequences than necessary. Note that Java is

 * capable of producing these sequences if provoked. Also note, this

 * routine checks for the 4-byte maximum size, but does not check for

 * 0x10ffff maximum value.

 *

 * Return value: true if @utf is valid.

 **/

int

xmlCheckUTF8(const unsigned char *utf)

{

    int ix;

    unsigned char c;

    if (utf == NULL)

        return(0);

    /*

     * utf is a string of 1, 2, 3 or 4 bytes.  The valid strings

     * are as follows (in "bit format"):

     *    0xxxxxxx                                      valid 1-byte

     *    110xxxxx 10xxxxxx                             valid 2-byte

     *    1110xxxx 10xxxxxx 10xxxxxx                    valid 3-byte

     *    11110xxx 10xxxxxx 10xxxxxx 10xxxxxx           valid 4-byte

     */

    for (ix = 0; (c = utf[ix]);) {      /* string is 0-terminated */

        if ((c & 0x80) == 0x00) {	/* 1-byte code, starts with 10 */

            ix++;

	} else if ((c & 0xe0) == 0xc0) {/* 2-byte code, starts with 110 */

	    if ((utf[ix+1] & 0xc0 ) != 0x80)

	        return 0;

	    ix += 2;

	} else if ((c & 0xf0) == 0xe0) {/* 3-byte code, starts with 1110 */

	    if (((utf[ix+1] & 0xc0) != 0x80) ||

	        ((utf[ix+2] & 0xc0) != 0x80))

		    return 0;

	    ix += 3;

	} else if ((c & 0xf8) == 0xf0) {/* 4-byte code, starts with 11110 */

	    if (((utf[ix+1] & 0xc0) != 0x80) ||

	        ((utf[ix+2] & 0xc0) != 0x80) ||

		((utf[ix+3] & 0xc0) != 0x80))

		    return 0;

	    ix += 4;

	} else				/* unknown encoding */

	    return 0;

      }

      return(1);

}

/**

 * xmlUTF8Strsize:

 * @utf:  a sequence of UTF-8 encoded bytes

 * @len:  the number of characters in the array

 *

 * storage size of an UTF8 string

 * the behaviour is not garanteed if the input string is not UTF-8

 *

 * Returns the storage size of

 * the first 'len' characters of ARRAY

 */

int

xmlUTF8Strsize(const xmlChar *utf, int len) {

    const xmlChar   *ptr=utf;

    xmlChar         ch;

    if (utf == NULL)

        return(0);

    if (len <= 0)

        return(0);

    while ( len-- > 0) {

        if ( !*ptr )

            break;

        if ( (ch = *ptr++) & 0x80)

            while ((ch<<=1) & 0x80 ) {

                ptr++;

		if (*ptr == 0) break;

	    }

    }

    return (ptr - utf);

}

/**

 * xmlUTF8Strndup:

 * @utf:  the input UTF8 *

 * @len:  the len of @utf (in chars)

 *

 * a strndup for array of UTF8's

 *

 * Returns a new UTF8 * or NULL

 */

xmlChar *

xmlUTF8Strndup(const xmlChar *utf, int len) {

    xmlChar *ret;

    int i;

    if ((utf == NULL) || (len < 0)) return(NULL);

    i = xmlUTF8Strsize(utf, len);

    ret = (xmlChar *) xmlMallocAtomic((i + 1) * sizeof(xmlChar));

    if (ret == NULL) {

        xmlGenericError(xmlGenericErrorContext,

                "malloc of %ld byte failed\n",

                (len + 1) * (long)sizeof(xmlChar));

        return(NULL);

    }

    memcpy(ret, utf, i * sizeof(xmlChar));

    ret[i] = 0;

    return(ret);

}

/**

 * xmlUTF8Strpos:

 * @utf:  the input UTF8 *

 * @pos:  the position of the desired UTF8 char (in chars)

 *

 * a function to provide the equivalent of fetching a

 * character from a string array

 *

 * Returns a pointer to the UTF8 character or NULL

 */

const xmlChar *

xmlUTF8Strpos(const xmlChar *utf, int pos) {

    xmlChar ch;

    if (utf == NULL) return(NULL);

    if (pos < 0)

        return(NULL);

    while (pos--) {

        if ((ch=*utf++) == 0) return(NULL);

        if ( ch & 0x80 ) {

            /* if not simple ascii, verify proper format */

            if ( (ch & 0xc0) != 0xc0 )

                return(NULL);

            /* then skip over remaining bytes for this char */

            while ( (ch <<= 1) & 0x80 )

                if ( (*utf++ & 0xc0) != 0x80 )

                    return(NULL);

        }

    }

    return((xmlChar *)utf);

}

/**

 * xmlUTF8Strloc:

 * @utf:  the input UTF8 *

 * @utfchar:  the UTF8 character to be found

 *

 * a function to provide the relative location of a UTF8 char

 *

 * Returns the relative character position of the desired char

 * or -1 if not found

 */

int

xmlUTF8Strloc(const xmlChar *utf, const xmlChar *utfchar) {

    int i, size;

    xmlChar ch;

    if (utf==NULL || utfchar==NULL) return -1;

    size = xmlUTF8Strsize(utfchar, 1);

        for(i=0; (ch=*utf) != 0; i++) {

            if (xmlStrncmp(utf, utfchar, size)==0)

                return(i);

            utf++;

            if ( ch & 0x80 ) {

                /* if not simple ascii, verify proper format */

                if ( (ch & 0xc0) != 0xc0 )

                    return(-1);

                /* then skip over remaining bytes for this char */

                while ( (ch <<= 1) & 0x80 )

                    if ( (*utf++ & 0xc0) != 0x80 )

                        return(-1);

            }

        }

    return(-1);

}

/**

 * xmlUTF8Strsub:

 * @utf:  a sequence of UTF-8 encoded bytes

 * @start: relative pos of first char

 * @len:   total number to copy

 *

 * Create a substring from a given UTF-8 string

 * Note:  positions are given in units of UTF-8 chars

 *

 * Returns a pointer to a newly created string

 * or NULL if any problem

 */

xmlChar *

xmlUTF8Strsub(const xmlChar *utf, int start, int len) {

    int            i;

    xmlChar ch;

    if (utf == NULL) return(NULL);

    if (start < 0) return(NULL);

    if (len < 0) return(NULL);

    /*

     * Skip over any leading chars

     */

    for (i = 0;i < start;i++) {

        if ((ch=*utf++) == 0) return(NULL);

        if ( ch & 0x80 ) {

            /* if not simple ascii, verify proper format */

            if ( (ch & 0xc0) != 0xc0 )

                return(NULL);

            /* then skip over remaining bytes for this char */

            while ( (ch <<= 1) & 0x80 )

                if ( (*utf++ & 0xc0) != 0x80 )

                    return(NULL);

        }

    }

    return(xmlUTF8Strndup(utf, len));

}

#define bottom_xmlstring

#include "elfgcchack.h"