src/corelib/tools/qstring.cpp

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/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at sales@trolltech.com.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "qstringlist.h"
#include "qregexp.h"
#include "qunicodetables_p.h"
#ifndef QT_NO_TEXTCODEC
#include <qtextcodec.h>
#endif
#include <qdatastream.h>
#include <qlist.h>
#include "qlocale.h"
#include "qlocale_p.h"
#include "qstringmatcher.h"
#include "qtools_p.h"
#include "qhash.h"
#include "qdebug.h"

#include <limits.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>

#ifdef truncate
#undef truncate
#endif

#ifndef LLONG_MAX
#define LLONG_MAX qint64_C(9223372036854775807)
#endif
#ifndef LLONG_MIN
#define LLONG_MIN (-LLONG_MAX - qint64_C(1))
#endif
#ifndef ULLONG_MAX
#define ULLONG_MAX quint64_C(18446744073709551615)
#endif


#ifndef QT_NO_TEXTCODEC
QTextCodec *QString::codecForCStrings;
#endif

#ifdef QT3_SUPPORT
static QHash<void *, QByteArray> *asciiCache = 0;
#endif

static int ucstrcmp(const QString &as, const QString &bs)
{
    const QChar *a = as.unicode();
    const QChar *b = bs.unicode();
    if (a == b)
        return 0;
    int l = qMin(as.length(),bs.length());
    while (l-- && *a == *b)
        a++,b++;
    if (l == -1)
        return (as.length()-bs.length());
    return a->unicode() - b->unicode();
}

static int ucstricmp(const QString &as, const QString &bs)
{
    const QChar *a = as.unicode();
    const QChar *b = bs.unicode();
    if (a == b)
        return 0;
    if (a == 0)
        return 1;
    if (b == 0)
        return -1;
    int l=qMin(as.length(),bs.length());
    while (l-- && QUnicodeTables::lower(*a) == QUnicodeTables::lower(*b))
        a++,b++;
    if (l==-1)
        return (as.length()-bs.length());
    return QUnicodeTables::lower(*a).unicode() - QUnicodeTables::lower(*b).unicode();
}

static int ucstrncmp(const QChar *a, const QChar *b, int l)
{
    while (l-- && *a == *b)
        a++,b++;
    if (l==-1)
        return 0;
    return a->unicode() - b->unicode();
}

static int ucstrnicmp(const QChar *a, const QChar *b, int l)
{
    while (l-- && QUnicodeTables::lower(*a) == QUnicodeTables::lower(*b))
        a++,b++;
    if (l==-1)
        return 0;
    return QUnicodeTables::lower(*a).unicode() - QUnicodeTables::lower(*b).unicode();
}


inline bool qIsUpper(char ch)
{
    return ch >= 'A' && ch <= 'Z';
}

inline bool qIsDigit(char ch)
{
    return ch >= '0' && ch <= '9';
}

inline char qToLower(char ch)
{
    if (ch >= 'A' && ch <= 'Z')
        return ch - 'A' + 'a';
    else
        return ch;
}

const QString::Null QString::null = QString::Null();

QString::Data QString::shared_null = { Q_ATOMIC_INIT(1), 0, 0, shared_null.array, 0, 0, 0, 0, 0, {0} };
QString::Data QString::shared_empty = { Q_ATOMIC_INIT(1), 0, 0, shared_empty.array, 0, 0, 0, 0, 0, {0} };

inline int QString::grow(int size)
{
    return qAllocMore(size * sizeof(QChar), sizeof(Data)) / sizeof(QChar);
}

QString QString::fromWCharArray(const wchar_t *string, int size)
{
    if (sizeof(wchar_t) == sizeof(QChar)) {
        return fromUtf16((ushort *)string, size);
    } else {
        return fromUcs4((uint *)string, size);
    }
}

int QString::toWCharArray(wchar_t *array) const
{
    if (sizeof(wchar_t) == sizeof(QChar)) {
        memcpy(array, utf16(), sizeof(wchar_t)*length());
        return length();
    } else {
        wchar_t *a = array;
        const unsigned short *uc = utf16();
        for (int i = 0; i < length(); ++i) {
            uint u = uc[i];
            if (u >= 0xd800 && u < 0xdc00 && i < length()-1) {
                ushort low = uc[i+1];
                if (low >= 0xdc00 && low < 0xe000) {
                    ++i;
                    u = (u - 0xd800)*0x400 + (low - 0xdc00) + 0x10000;
                }
            }
            *a = wchar_t(u);
            ++a;
        }
        return a - array;
    }
}

QString::QString(const QChar *unicode, int size)
{
   if (!unicode) {
        d = &shared_null;
        d->ref.ref();
    } else if (size <= 0) {
        d = &shared_empty;
        d->ref.ref();
    } else {
        d = (Data*) qMalloc(sizeof(Data)+size*sizeof(QChar));
        d->ref.init(1);
        d->alloc = d->size = size;
        d->clean = d->asciiCache = d->simpletext = d->righttoleft = 0;
        d->data = d->array;
        memcpy(d->array, unicode, size * sizeof(QChar));
        d->array[size] = '\0';
    }
}


QString::QString(int size, QChar ch)
{
   if (size <= 0) {
        d = &shared_empty;
        d->ref.ref();
    } else {
        d = (Data*) qMalloc(sizeof(Data)+size*sizeof(QChar));
        d->ref.init(1);
        d->alloc = d->size = size;
        d->clean = d->asciiCache = d->simpletext = d->righttoleft = 0;
        d->data = d->array;
        d->array[size] = '\0';
        ushort *i = d->array + size;
        ushort *b = d->array;
        const ushort value = ch.unicode();
        while (i != b)
           *--i = value;
    }
}

QString::QString(QChar ch)
{
    d = (Data *)qMalloc(sizeof(Data) + sizeof(QChar));
    d->ref.init(1);
    d->alloc = d->size = 1;
    d->clean = d->asciiCache = d->simpletext = d->righttoleft = 0;
    d->data = d->array;
    d->array[0] = ch.unicode();
    d->array[1] = '\0';
}

void QString::free(Data *d)
{
#ifdef QT3_SUPPORT
    if (d->asciiCache) {
        Q_ASSERT(asciiCache);
        asciiCache->remove(d);
    }
#endif
    qFree(d);
}

void QString::resize(int size)
{
    if (size <= 0) {
        Data *x = &shared_empty;
        x->ref.ref();
        x = qAtomicSetPtr(&d, x);
        if (!x->ref.deref())
            free(x);
    } else {
        if (d->ref != 1 || size > d->alloc || (size < d->size && size < d->alloc >> 1))
            realloc(grow(size));
        if (d->alloc >= size) {
            d->size = size;
            if (d->data == d->array) {
                d->array[size] = '\0';
            }
        }
    }
}

void QString::realloc(int alloc)
{
    if (d->ref != 1 || d->data != d->array) {
        Data *x = static_cast<Data *>(qMalloc(sizeof(Data) + alloc * sizeof(QChar)));
        if (!x)
            return;
        x->size = qMin(alloc, d->size);
        ::memcpy(x->array, d->data, x->size * sizeof(QChar));
        x->array[x->size] = 0;
        x->asciiCache = 0;
        x->ref.init(1);
        x->alloc = alloc;
        x->clean = d->clean;
        x->simpletext = d->simpletext;
        x->righttoleft = d->righttoleft;
        x->data = x->array;
        x = qAtomicSetPtr(&d, x);
        if (!x->ref.deref())
            free(x);
    } else {
#ifdef QT3_SUPPORT
        if (d->asciiCache) {
            Q_ASSERT(asciiCache);
            asciiCache->remove(d);
        }
#endif
        Data *x = static_cast<Data *>(qRealloc(d, sizeof(Data) + alloc * sizeof(QChar)));
        if (!x)
            return;
        x->alloc = alloc;
        x->data = x->array;
        d = x;
    }
}

void QString::realloc()
{
    realloc(d->size);
}

void QString::expand(int i)
{
    int sz = d->size;
    resize(qMax(i + 1, sz));
    if (d->size - 1 > sz) {
        ushort *n = d->data + d->size - 1;
        ushort *e = d->data + sz;
        while (n != e)
           * --n = ' ';
    }
}

QString &QString::operator=(const QString &other)
{
    Data *x = other.d;
    x->ref.ref();
    x = qAtomicSetPtr(&d, x);
    if (!x->ref.deref())
        free(x);
    return *this;
}


QString &QString::operator=(QChar ch)
{
    return operator=(QString(ch));
}

QString &QString::insert(int i, const QLatin1String &str)
{
    const uchar *s = (const uchar *)str.latin1();
    if (i < 0 || !s || !(*s))
        return *this;

    int len = qstrlen(str.latin1());
    expand(qMax(d->size, i) + len - 1);

    ::memmove(d->data + i + len, d->data + i, (d->size - i - len) * sizeof(QChar));
    for (int j = 0; j < len; ++j)
        d->data[i + j] = s[j];
    return *this;
}

QString& QString::insert(int i, const QChar *unicode, int size)
{
    if (i < 0 || size <= 0)
        return *this;

    const ushort *s = (const ushort *)unicode;
    if (s >= d->data && s < d->data + d->alloc) {
        // Part of me - take a copy
        ushort *tmp = static_cast<ushort *>(malloc(size * sizeof(QChar)));
        memcpy(tmp, s, size * sizeof(QChar));
        insert(i, reinterpret_cast<const QChar *>(tmp), size);
        ::free(tmp);
        return *this;
    }

    expand(qMax(d->size, i) + size - 1);

    ::memmove(d->data + i + size, d->data + i, (d->size - i - size) * sizeof(QChar));
    memcpy(d->data + i, s, size * sizeof(QChar));
    return *this;
}

QString& QString::insert(int i, QChar ch)
{
    if (i < 0)
        i += d->size;
    if (i < 0)
        return *this;
    expand(qMax(i, d->size));
    ::memmove(d->data + i + 1, d->data + i, (d->size - i) * sizeof(QChar));
    d->data[i] = ch.unicode();
    return *this;
}

QString &QString::append(const QString &str)
{
    if (str.d != &shared_null) {
        if (d == &shared_null) {
            operator=(str);
        } else {
            if (d->ref != 1 || d->size + str.d->size > d->alloc)
                realloc(grow(d->size + str.d->size));
            memcpy(d->data + d->size, str.d->data, str.d->size * sizeof(QChar));
            d->size += str.d->size;
            d->data[d->size] = '\0';
        }
    }
    return *this;
}

QString &QString::append(const QLatin1String &str)
{
    const uchar *s = (const uchar *)str.latin1();
    if (s) {
        int len = qstrlen((char *)s);
        if (d->ref != 1 || d->size + len > d->alloc)
            realloc(grow(d->size + len));
        ushort *i = d->data + d->size;
        while ((*i++ = *s++))
            ;
        d->size += len;
    }
    return *this;
}

QString &QString::append(QChar ch)
{
    if (d->ref != 1 || d->size + 1 > d->alloc)
        realloc(grow(d->size + 1));
    d->data[d->size++] = ch.unicode();
    d->data[d->size] = '\0';
    return *this;
}

QString &QString::remove(int pos, int len)
{
    if (pos < 0)
        pos += d->size;
    if (pos < 0 || pos >= d->size) {
        // range problems
    } else if (pos + len >= d->size) {  // pos ok
        resize(pos);
    } else if (len > 0) {
        detach();
        memmove(d->data + pos, d->data + pos + len,
                (d->size - pos - len + 1) * sizeof(ushort));
        d->size -= len;
    }
    return *this;
}

QString &QString::remove(const QString &str, Qt::CaseSensitivity cs)
{
    if (str.d->size) {
        int i = 0;
        while ((i = indexOf(str, i, cs)) != -1)
            remove(i, str.d->size);
    }
    return *this;
}

QString &QString::remove(QChar ch, Qt::CaseSensitivity cs)
{
    int i = 0;
    if (cs == Qt::CaseSensitive) {
        while (i < d->size)
            if (*((const QChar*)d->data + i) == ch)
                remove(i, 1);
            else
                i++;
    } else {
        ch = QUnicodeTables::lower(ch);
        while (i < d->size)
            if (QUnicodeTables::lower(*((const QChar*)d->data + i)) == ch)
                remove(i, 1);
            else
                i++;
    }
    return *this;
}

QString &QString::replace(int pos, int len, const QString &after)
{
    QString copy = after;
    remove(pos, len);
    return insert(pos, copy.constData(), copy.d->size);
}

QString &QString::replace(int pos, int len, const QChar *unicode, int size)
{
    remove(pos, len);
    return insert(pos, unicode, size);
}

QString &QString::replace(int pos, int len, QChar after)
{
    remove(pos, len);
    return insert(pos, after);
}

QString &QString::replace(const QString &before, const QString &after, Qt::CaseSensitivity cs)
{
    if (d->size == 0) {
        if (before.d->size)
            return *this;
    } else {
        if (cs == Qt::CaseSensitive && before == after)
            return *this;
    }
    if (d->ref != 1)
        realloc(d->size);

    QStringMatcher matcher(before, cs);
    int index = 0;
    const int bl = before.d->size;
    const int al = after.d->size;

    if (bl == al) {
        if (bl) {
            const QChar *auc = (const QChar*) after.d->data;
            while ((index = matcher.indexIn(*this, index)) != -1) {
                // we need memmove(), not memcpy(), in the rare case where
                // this == &after, before == after, and cs is Qt::CaseInsensitive
                memmove(d->data + index, auc, al * sizeof(QChar));
                index += bl;
            }
        }
    } else if (al < bl) {
        const QChar *auc = after.unicode();
        uint to = 0;
        uint movestart = 0;
        uint num = 0;
        while ((index = matcher.indexIn(*this, index)) != -1) {
            if (num) {
                int msize = index - movestart;
                if (msize > 0) {
                    memmove(d->data + to, d->data + movestart, msize * sizeof(QChar));
                    to += msize;
                }
            } else {
                to = index;
            }
            if (al) {
                memcpy(d->data+to, auc, al*sizeof(QChar));
                to += al;
            }
            index += bl;
            movestart = index;
            num++;
        }
        if (num) {
            int msize = d->size - movestart;
            if (msize > 0)
                memmove(d->data + to, d->data + movestart, msize * sizeof(QChar));
            resize(d->size - num*(bl-al));
        }
    } else {
        const QString copy = after;

        // the most complex case. We don't want to lose performance by doing repeated
        // copies and reallocs of the string.
        while (index != -1) {
            uint indices[4096];
            uint pos = 0;
            while (pos < 4095) {
                index = matcher.indexIn(*this, index);
                if (index == -1)
                    break;
                indices[pos++] = index;
                index += bl;
                // avoid infinite loop
                if (!bl)
                    index++;
            }
            if (!pos)
                break;

            // we have a table of replacement positions, use them for fast replacing
            int adjust = pos*(al-bl);
            // index has to be adjusted in case we get back into the loop above.
            if (index != -1)
                index += adjust;
            int newLen = d->size + adjust;
            int moveend = d->size;
            if (newLen > d->size)
                resize(newLen);

            while (pos) {
                pos--;
                int movestart = indices[pos] + bl;
                int insertstart = indices[pos] + pos*(al-bl);
                int moveto = insertstart + al;
                memmove(d->data + moveto, d->data + movestart, (moveend - movestart)*sizeof(QChar));
                memcpy(d->data + insertstart, copy.unicode(), al*sizeof(QChar));
                moveend = movestart-bl;
            }
        }
    }
    return *this;
}

QString& QString::replace(QChar ch, const QString &after, Qt::CaseSensitivity cs)
{
    return replace(QString(ch), after, cs);
}

QString& QString::replace(QChar before, QChar after, Qt::CaseSensitivity cs)
{
    if (d->size) {
        QChar *i = data();
        QChar *e = i + d->size;
        if (cs == Qt::CaseSensitive) {
            for (; i != e; ++i)
                if (*i == before)
                   * i = after;
        } else {
            before = QUnicodeTables::lower(before);
            for (; i != e; ++i)
                if (QUnicodeTables::lower(*i) == before)
                   * i = after;
        }
    }
    return *this;
}

bool QString::operator==(const QString &other) const
{
    return (size() == other.size()) &&
        (memcmp((char*)unicode(),(char*)other.unicode(), size()*sizeof(QChar))==0);
}

bool QString::operator==(const QLatin1String &other) const
{
    const ushort *uc = d->data;
    const ushort *e = uc + d->size;
    const uchar *c = (uchar *)other.latin1();

    if (!c)
        return isEmpty();

    while (*c) {
        if (uc == e || *uc != *c)
            return false;
        ++uc;
        ++c;
    }
    return (uc == e);
}

bool QString::operator<(const QString &other) const
{
    return ucstrcmp(*this, other) < 0;
}

bool QString::operator<(const QLatin1String &other) const
{
    const ushort *uc = d->data;
    const ushort *e = uc + d->size;
    const uchar *c = (uchar *) other.latin1();

    if (!c || *c == 0)
        return false;

    while (*c) {
        if (uc == e || *uc != *c)
            break;
        ++uc;
        ++c;
    }
    return (uc == e ? *c : *uc < *c);
}

bool QString::operator>(const QLatin1String &other) const
{
    const ushort *uc = d->data;;
    const ushort *e = uc + d->size;
    const uchar *c = (uchar *) other.latin1();

    if (!c || *c == '\0')
        return !isEmpty();

    while (*c) {
        if (uc == e || *uc != *c)
            break;
        ++uc;
        ++c;
    }
    return (uc == e ? false : *uc > *c);
}

#define REHASH(a) \
    if (sl_minus_1 < (int)sizeof(int) * CHAR_BIT)       \
        hashHaystack -= (a) << sl_minus_1; \
    hashHaystack <<= 1

int QString::indexOf(const QString &str, int from, Qt::CaseSensitivity cs) const
{
    const int l = d->size;
    const int sl = str.d->size;
    if (from < 0)
        from += l;
    if (uint(sl + from) > (uint)l)
        return -1;
    if (!sl)
        return from;
    if (!l)
        return -1;

    if (sl == 1)
        return indexOf(*(const QChar *)str.d->data, from, cs);

    /*
        We use the Boyer-Moore algorithm in cases where the overhead
        for the skip table should pay off, otherwise we use a simple
        hash function.
    */
    if (l > 500 && sl > 5)
        return QStringMatcher(str, cs).indexIn(*this, from);

    /*
        We use some hashing for efficiency's sake. Instead of
        comparing strings, we compare the hash value of str with that
        of a part of this QString. Only if that matches, we call
        ucstrncmp() or ucstrnicmp().
    */
    const QChar *needle = (const QChar*) str.d->data;
    const QChar *haystack = (const QChar*) d->data + from;
    const QChar *end = (const QChar*) d->data + (l-sl);
    const int sl_minus_1 = sl-1;
    int hashNeedle = 0, hashHaystack = 0, idx;

    if (cs == Qt::CaseSensitive) {
        for (idx = 0; idx < sl; ++idx) {
            hashNeedle = ((hashNeedle<<1) + needle[idx].unicode());
            hashHaystack = ((hashHaystack<<1) + haystack[idx].unicode());
        }
        hashHaystack -= (haystack+sl_minus_1)->unicode();

        while (haystack <= end) {
            hashHaystack += (haystack+sl_minus_1)->unicode();
            if (hashHaystack == hashNeedle
                 && ucstrncmp(needle, haystack, sl) == 0)
                return haystack-unicode();

            REHASH(haystack->unicode());
            ++haystack;
        }
    } else {
        for (idx = 0; idx < sl; ++idx) {
            hashNeedle = ((hashNeedle<<1) +
                          QUnicodeTables::lower(needle[idx].unicode()));
            hashHaystack = ((hashHaystack<<1) +
                            QUnicodeTables::lower(haystack[idx].unicode()));
        }

        hashHaystack -= QUnicodeTables::lower(*(haystack+sl_minus_1)).unicode();
        while (haystack <= end) {
            hashHaystack += QUnicodeTables::lower(*(haystack+sl_minus_1)).unicode();
            if (hashHaystack == hashNeedle
                 && ucstrnicmp(needle, haystack, sl) == 0)
                return haystack-unicode();

            REHASH(QUnicodeTables::lower(*haystack).unicode());
            ++haystack;
        }
    }
    return -1;
}

int QString::indexOf(QChar ch, int from, Qt::CaseSensitivity cs) const
{
    if (from < 0)
        from = qMax(from + d->size, 0);
    if (from  < d->size) {
        const QChar *n = (const QChar*)d->data + from - 1;
        const QChar *e = (const QChar*)d->data + d->size;
        if (cs == Qt::CaseSensitive) {
            while (++n != e)
                if (*n == ch)
                    return  n - (const QChar*)d->data;
        } else {
            ch = QUnicodeTables::lower(ch);
            while (++n != e)
                if (QUnicodeTables::lower(*n) == ch)
                    return  n - (const QChar*)d->data;
        }
    }
    return -1;
}

int QString::lastIndexOf(const QString &str, int from, Qt::CaseSensitivity cs) const
{
    /*
        See indexOf() for explanations.
    */
    const int l = d->size;
    if (from < 0)
        from += l;
    const int sl = str.d->size;
    int delta = l-sl;
    if (from == l && sl == 0)
        return from;
    if (from < 0 || from >= l || delta < 0)
        return -1;
    if (from > delta)
        from = delta;

    if (sl == 1)
        return lastIndexOf(*(const QChar*) str.d->data, from, cs);

    const QChar *needle = (const QChar*) str.d->data;
    const QChar *haystack = (const QChar*) d->data + from;
    const QChar *end = (const QChar*) d->data;
    const int sl_minus_1 = sl-1;
    const QChar *n = needle+sl_minus_1;
    const QChar *h = haystack+sl_minus_1;
    int hashNeedle = 0, hashHaystack = 0, idx;

    if (cs == Qt::CaseSensitive) {
        for (idx = 0; idx < sl; ++idx) {
            hashNeedle = ((hashNeedle<<1) + (n-idx)->unicode());
            hashHaystack = ((hashHaystack<<1) + (h-idx)->unicode());
        }
        hashHaystack -= haystack->unicode();

        while (haystack >= end) {
            hashHaystack += haystack->unicode();
            if (hashHaystack == hashNeedle
                 && ucstrncmp(needle, haystack, sl) == 0)
                return haystack-unicode();
            --haystack;
            REHASH((haystack+sl)->unicode());
        }
    } else {
        for (idx = 0; idx < sl; ++idx) {
            hashNeedle = ((hashNeedle<<1)
                          + QUnicodeTables::lower((n-idx)->unicode()));
            hashHaystack = ((hashHaystack<<1)
                            + QUnicodeTables::lower((h-idx)->unicode()));
        }
        hashHaystack -= QUnicodeTables::lower(*haystack).unicode();

        while (haystack >= end) {
            hashHaystack += QUnicodeTables::lower(*haystack).unicode();
            if (hashHaystack == hashNeedle
                 && ucstrnicmp(needle, haystack, sl) == 0)
                return haystack-unicode();
            --haystack;
            REHASH(QUnicodeTables::lower(*(haystack+sl)).unicode());
        }
    }
    return -1;
}

int QString::lastIndexOf(QChar ch, int from, Qt::CaseSensitivity cs) const
{
    if (from < 0)
        from += d->size;
    if (from < 0 || from >= d->size)
        return -1;
    if (from >= 0) {
        const QChar *n =  (const QChar*)d->data + from;
        const QChar *b = (const QChar*)d->data;
        if (cs == Qt::CaseSensitive) {
            for (; n >= b; --n)
                if (*n == ch)
                    return  n - b;
        } else {
            ch = QUnicodeTables::lower(ch);
            for (; n >= b; --n)
                if (QUnicodeTables::lower(*n) == ch)
                    return  n - b;
        }
    }
    return -1;
}

#ifndef QT_NO_REGEXP

QString& QString::replace(const QRegExp &rx, const QString &after)
{
    QRegExp rx2(rx);

    if (isEmpty() && rx2.indexIn(*this) == -1)
        return *this;

    realloc();

    int index = 0;
    int numCaptures = rx2.numCaptures();
    int al = after.length();
    QRegExp::CaretMode caretMode = QRegExp::CaretAtZero;

    if (numCaptures > 0) {
        if (numCaptures > 9)
            numCaptures = 9;

        const QChar *uc = after.unicode();
        int numBackRefs = 0;

        for (int i = 0; i < al - 1; i++) {
            if (uc[i] == QLatin1Char('\\')) {
                int no = uc[i + 1].digitValue();
                if (no > 0 && no <= numCaptures)
                    numBackRefs++;
            }
        }

        /*
          This is the harder case where we have back-references.
          We don't try to optimize it.
        */
        if (numBackRefs > 0) {
            int *capturePositions = new int[numBackRefs];
            int *captureNumbers = new int[numBackRefs];
            int j = 0;

            for (int i = 0; i < al - 1; i++) {
                if (uc[i] == QLatin1Char('\\')) {
                    int no = uc[i + 1].digitValue();
                    if (no > 0 && no <= numCaptures) {
                        capturePositions[j] = i;
                        captureNumbers[j] = no;
                        j++;
                    }
                }
            }

            while (index <= length()) {
                index = rx2.indexIn(*this, index, caretMode);
                if (index == -1)
                    break;

                QString after2 = after;
                for (j = numBackRefs - 1; j >= 0; j--)
                    after2.replace(capturePositions[j], 2,
                                    rx2.cap(captureNumbers[j]));

                replace(index, rx2.matchedLength(), after2);
                index += after2.length();

                if (rx2.matchedLength() == 0) {
                    // avoid infinite loop on 0-length matches (e.g., [a-z]*)
                    index++;
                }
                caretMode = QRegExp::CaretWontMatch;
            }
            delete[] capturePositions;
            delete[] captureNumbers;
            return *this;
        }
    }

    /*
      This is the simple and optimized case where we don't have
      back-references.
   */
    while (index != -1) {
        struct {
            int pos;
            int length;
        } replacements[2048];

        int pos = 0;
        int adjust = 0;
        while (pos < 2047) {
            index = rx2.indexIn(*this, index, caretMode);
            if (index == -1)
                break;
            int ml = rx2.matchedLength();
            replacements[pos].pos = index;
            replacements[pos++].length = ml;
            index += ml;
            adjust += al - ml;
            // avoid infinite loop
            if (!ml)
                index++;
        }
        if (!pos)
            break;
        replacements[pos].pos = d->size;
        int newlen = d->size + adjust;

        // to continue searching at the right position after we did
        // the first round of replacements
        if (index != -1)
            index += adjust;
        QString newstring;
        newstring.reserve(newlen + 1);
        QChar *newuc = newstring.data();
        QChar *uc = newuc;
        int copystart = 0;
        int i = 0;
        while (i < pos) {
            int copyend = replacements[i].pos;
            int size = copyend - copystart;
            memcpy(uc, d->data + copystart, size * sizeof(QChar));
            uc += size;
            memcpy(uc, after.d->data, al * sizeof(QChar));
            uc += al;
            copystart = copyend + replacements[i].length;
            i++;
        }
        memcpy(uc, d->data + copystart, (d->size - copystart) * sizeof(QChar));
        newstring.resize(newlen);
        *this = newstring;
        caretMode = QRegExp::CaretWontMatch;
    }
    return *this;
}
#endif

int QString::count(const QString &str, Qt::CaseSensitivity cs) const
{
    int num = 0;
    int i = -1;
    if (d->size > 500 && str.d->size > 5) {
        QStringMatcher matcher(str, cs);
        while ((i = matcher.indexIn(*this, i + 1)) != -1)
            ++num;
    } else {
        while ((i = indexOf(str, i + 1, cs)) != -1)
            ++num;
    }
    return num;
}

int QString::count(QChar ch, Qt::CaseSensitivity cs) const
{
    int num = 0;
    const QChar *i = (const QChar*) d->data + d->size;
    const QChar *b = (const QChar*) d->data;
    if (cs == Qt::CaseSensitive) {
        while (i != b)
            if (*--i == ch)
                ++num;
    } else {
        ch = QUnicodeTables::lower(ch);
        while (i != b)
            if (QUnicodeTables::lower(*--i) == ch)
                ++num;
    }
    return num;
}

#ifndef QT_NO_REGEXP

int QString::indexOf(const QRegExp& rx, int from) const
{
    return rx.indexIn(*this, from);
}

int QString::lastIndexOf(const QRegExp& rx, int from) const
{
    return rx.lastIndexIn(*this, from);
}

int QString::count(const QRegExp& rx) const
{
    int count = 0;
    int index = -1;
    int len = length();
    while (index < len - 1) {                 // count overlapping matches
        index = rx.indexIn(*this, index + 1);
        if (index == -1)
            break;
        count++;
    }
    return count;
}
#endif // QT_NO_REGEXP

QString QString::section(const QString &sep, int start, int end, SectionFlags flags) const
{
    QStringList sections = split(sep, KeepEmptyParts,
                                 (flags & SectionCaseInsensitiveSeps) ? Qt::CaseInsensitive : Qt::CaseSensitive);
    if (sections.isEmpty())
        return QString();
    if (!(flags & SectionSkipEmpty)) {
        if (start < 0)
            start += sections.count();
        if (end < 0)
            end += sections.count();
    } else {
        int skip = 0;
        for (int k=0; k<sections.size(); ++k) {
            if (sections.at(k).isEmpty())
                skip++;
        }
        if (start < 0)
            start += sections.count() - skip;
        if (end < 0)
            end += sections.count() - skip;
    }
    int x = 0;
    QString ret;
    int first_i = start, last_i = end;
    for (int i = 0; x <= end && i < sections.size(); ++i) {
        QString section = sections.at(i);
        const bool empty = section.isEmpty();
        if (x >= start) {
            if(x == start)
                first_i = i;
            if(x == end)
                last_i = i;
            if(x > start)
                ret += sep;
            ret += section;
        }
        if (!empty || !(flags & SectionSkipEmpty))
            x++;
    }
    if((flags & SectionIncludeLeadingSep) && first_i)
        ret.prepend(sep);
    if((flags & SectionIncludeTrailingSep) && last_i < sections.size()-1)
        ret += sep;
    return ret;
}

#ifndef QT_NO_REGEXP
class qt_section_chunk {
public:
    qt_section_chunk(int l, QString s) { length = l; string = s; }
    int length;
    QString string;
};

QString QString::section(const QRegExp &reg, int start, int end, SectionFlags flags) const
{
    const QChar *uc = unicode();
    if(!uc)
        return QString();

    QRegExp sep(reg);
    sep.setCaseSensitivity((flags & SectionCaseInsensitiveSeps) ? Qt::CaseInsensitive
                                                                : Qt::CaseSensitive);

    QList<qt_section_chunk> sections;
    int n = length(), m = 0, last_m = 0, last_len = 0;
    while ((m = sep.indexIn(*this, m)) != -1) {
        sections.append(qt_section_chunk(last_len, QString(uc + last_m, m - last_m)));
        last_m = m;
        last_len = sep.matchedLength();
        m += qMax(sep.matchedLength(), 1);
    }
    sections.append(qt_section_chunk(last_len, QString(uc + last_m, n - last_m)));

    if(start < 0)
        start += sections.count();
    if(end < 0)
        end += sections.count();

    QString ret;
    int x = 0;
    int first_i = start, last_i = end;
    for (int i = 0; x <= end && i < sections.size(); ++i) {
        const qt_section_chunk &section = sections.at(i);
        const bool empty = (section.length == section.string.length());
        if (x >= start) {
            if(x == start)
                first_i = i;
            if(x == end)
                last_i = i;
            if(x != start)
                ret += section.string;
            else
                ret += section.string.mid(section.length);
        }
        if (!empty || !(flags & SectionSkipEmpty))
            x++;
    }
    if((flags & SectionIncludeLeadingSep)) {
        const qt_section_chunk &section = sections.at(first_i);
        ret.prepend(section.string.left(section.length));
    }
    if((flags & SectionIncludeTrailingSep) && last_i+1 <= sections.size()-1) {
        const qt_section_chunk &section = sections.at(last_i+1);
        ret += section.string.left(section.length);
    }
    return ret;
}
#endif

QString QString::left(int len)  const
{
    if (d == &shared_null)
        return QString();
    if (len >= d->size || len < 0)
        return *this;
    return QString((const QChar*) d->data, len);
}

QString QString::right(int len) const
{
    if (d == &shared_null)
        return QString();
    if (len >= d->size || len < 0)
        return *this;
    return QString((const QChar*) d->data + d->size - len, len);
}

QString QString::mid(int i, int len) const
{
    if (d == &shared_null || i >= d->size)
        return QString();
    if (len < 0)
        len = d->size - i;
    if (i < 0) {
        len += i;
        i = 0;
    }
    if (len + i > d->size)
        len = d->size - i;
    if (i == 0 && len == d->size)
        return *this;
    return QString((const QChar*) d->data + i, len);
}

bool QString::startsWith(const QString& s, Qt::CaseSensitivity cs) const
{
    if (d == &shared_null)
        return (s.d == &shared_null);
    if (d->size == 0)
        return s.d->size == 0;
    if (s.d->size > d->size)
        return false;
    if (cs == Qt::CaseSensitive) {
        return memcmp((char*)d->data, (char*)s.d->data, s.d->size*sizeof(QChar)) == 0;
    } else {
        for (int i = 0; i < s.d->size; ++i)
            if (QUnicodeTables::lower(d->data[i]) != QUnicodeTables::lower(s.d->data[i]))
                return false;
    }
    return true;
}

bool QString::startsWith(const QLatin1String& s, Qt::CaseSensitivity cs) const
{
    if (d == &shared_null)
        return (s.latin1() == 0);
    if (d->size == 0)
        return !s.latin1() || *s.latin1() == 0;
    int slen = qstrlen(s.latin1());
    if (slen > d->size)
        return false;
    const uchar *latin = (const uchar *)s.latin1();
    if (cs == Qt::CaseSensitive) {
        for (int i = 0; i < slen; ++i)
            if (d->data[i] != latin[i])
                return false;
    } else {
        for (int i = 0; i < slen; ++i)
            if (QUnicodeTables::lower(d->data[i]) != QUnicodeTables::lower(latin[i]))
                return false;
    }
    return true;
}

bool QString::startsWith(const QChar &c, Qt::CaseSensitivity cs) const
{
    return d->size
           && (cs == Qt::CaseSensitive
               ? d->data[0] == c
               : QUnicodeTables::lower(d->data[0]) == QUnicodeTables::lower(c.unicode()));
}

bool QString::endsWith(const QString& s, Qt::CaseSensitivity cs) const
{
    if (d == &shared_null)
        return (s.d == &shared_null);
    if (d->size == 0)
        return s.d->size == 0;
    int pos = d->size - s.d->size;
    if (pos < 0)
        return false;
    if (cs == Qt::CaseSensitive) {
        return memcmp((char*)&d->data[pos], (char*)s.d->data, s.d->size*sizeof(QChar)) == 0;
    } else {
        for (int i = 0; i < s.length(); i++)
            if (QUnicodeTables::lower(d->data[pos+i]) != QUnicodeTables::lower(s.d->data[i]))
                return false;
    }
    return true;
}

bool QString::endsWith(const QLatin1String& s, Qt::CaseSensitivity cs) const
{
    if (d == &shared_null)
        return (s.latin1() == 0);
    if (d->size == 0)
        return !s.latin1() || *s.latin1() == 0;
    int slen = qstrlen(s.latin1());
    int pos = d->size - slen;
    const uchar *latin = (const uchar *)s.latin1();
    if (pos < 0)
        return false;
    if (cs == Qt::CaseSensitive) {
        for (int i = 0; i < slen; i++)
            if (d->data[pos+i] != latin[i])
                return false;
    } else {
        for (int i = 0; i < slen; i++)
            if (QUnicodeTables::lower(d->data[pos+i]) != QUnicodeTables::lower(latin[i]))
                return false;
    }
    return true;
}

bool QString::endsWith(const QChar &c, Qt::CaseSensitivity cs) const
{
    return d->size
           && (cs == Qt::CaseSensitive
               ? d->data[d->size - 1] == c
               : QUnicodeTables::lower(d->data[d->size - 1]) == QUnicodeTables::lower(c.unicode()));
}

QByteArray QString::toLatin1() const
{
    QByteArray ba;
    if (d->size) {
        ba.resize(d->size);
        const ushort *i = d->data;
        const ushort *e = d->data + d->size;
        uchar *s = (uchar*) ba.data();
        while (i != e) {
            *s++ = (*i>0xff) ? '?' : (uchar) *i;
            ++i;
        }
    }
    return ba;
}

QByteArray QString::toAscii() const
{
#ifndef QT_NO_TEXTCODEC
    if (codecForCStrings)
        return codecForCStrings->fromUnicode(*this);
#endif // QT_NO_TEXTCODEC
    return toLatin1();
}

QByteArray QString::toLocal8Bit() const
{
#ifndef QT_NO_TEXTCODEC
    if (QTextCodec::codecForLocale())
        return QTextCodec::codecForLocale()->fromUnicode(*this);
#endif // QT_NO_TEXTCODEC
    return toLatin1();
}

QByteArray QString::toUtf8() const
{
    QByteArray ba;
    if (d->size) {
        int l = d->size;
        int rlen = l*3+1;
        ba.resize(rlen);
        uchar *cursor = (uchar*)ba.data();
        const ushort *ch =d->data;
        for (int i=0; i < l; i++) {
            uint u = *ch;
            if (u < 0x80) {
                *cursor++ = (uchar)u;
            } else {
                if (u < 0x0800) {
                    *cursor++ = 0xc0 | ((uchar) (u >> 6));
                } else {
                    if (u >= 0xd800 && u < 0xdc00 && i < l-1) {
                        ushort low = ch[1];
                        if (low >= 0xdc00 && low < 0xe000) {
                            ++ch;
                            ++i;
                            u = (u - 0xd800)*0x400 + (low - 0xdc00) + 0x10000;
                        }
                    }
                    if (u > 0xffff) {
                        // if people are working in utf8, but strings are encoded in eg. latin1, the resulting
                        // name might be invalid utf8. This and the corresponding code in fromUtf8 takes care
                        // we can handle this without loosing information. This can happen with latin filenames
                        // and a utf8 locale under Unix.
                        if (u > 0x10fe00 && u < 0x10ff00) {
                            *cursor++ = (u - 0x10fe00);
                            ++ch;
                            continue;
                        } else {
                            *cursor++ = 0xf0 | ((uchar) (u >> 18));
                            *cursor++ = 0x80 | (((uchar) (u >> 12)) & 0x3f);
                        }
                    } else {
                        *cursor++ = 0xe0 | ((uchar) (u >> 12));
                    }
                    *cursor++ = 0x80 | (((uchar) (u >> 6)) & 0x3f);
                }
                *cursor++ = 0x80 | ((uchar) (u&0x3f));
            }
            ++ch;
        }
        ba.resize(cursor - (uchar*)ba.constData());
    }
    return ba;
}

QVector<uint> QString::toUcs4() const
{
    QVector<uint> v(length());
    uint *a = v.data();
    const unsigned short *uc = utf16();
    for (int i = 0; i < length(); ++i) {
        uint u = uc[i];
        if (u >= 0xd800 && u < 0xdc00 && i < length()-1) {
            ushort low = uc[i+1];
            if (low >= 0xdc00 && low < 0xe000) {
                ++i;
                u = (u - 0xd800)*0x400 + (low - 0xdc00) + 0x10000;
            }
        }
        *a = u;
        ++a;
    }
    v.resize(a - v.data());
    return v;
}

QString::Data *QString::fromLatin1_helper(const char *str, int size)
{
    Data *d;
    if (!str) {
        d = &shared_null;
        d->ref.ref();
    } else if (size == 0 || (!*str && size < 0)) {
        d = &shared_empty;
        d->ref.ref();
    } else {
        if (size < 0)
            size = qstrlen(str);
        d = static_cast<Data *>(qMalloc(sizeof(Data) + size * sizeof(QChar)));
        d->ref.init(1);
        d->alloc = d->size = size;
        d->clean = d->asciiCache = d->simpletext = d->righttoleft = 0;
        d->data = d->array;
        ushort *i = d->data;
        d->array[size] = '\0';
        while (size--)
           *i++ = (uchar)*str++;
    }
    return d;
}

QString::Data *QString::fromAscii_helper(const char *str, int size)
{
#ifndef QT_NO_TEXTCODEC
    if (codecForCStrings) {
        Data *d;
        if (!str) {
            d = &shared_null;
            d->ref.ref();
        } else if (size == 0 || (!*str && size < 0)) {
            d = &shared_empty;
            d->ref.ref();
        } else {
            if (size < 0)
                size = qstrlen(str);
            QString s = codecForCStrings->toUnicode(str, size);
            d = s.d;
            d->ref.ref();
        }
        return d;
    }
#endif
    return fromLatin1_helper(str, size);
}

QString QString::fromLatin1(const char *str, int size)
{
    return QString(fromLatin1_helper(str, size), 0);
}


#ifdef QT3_SUPPORT

const char *QString::ascii_helper() const
{
    if (!asciiCache)
        asciiCache = new QHash<void *, QByteArray>();

    d->asciiCache = true;
    QByteArray ascii = toAscii();
    QByteArray old = asciiCache->value(d);
    if (old == ascii)
        return old.constData();
    asciiCache->insert(d, ascii);
    return ascii.constData();
}

const char *QString::latin1_helper() const
{
    if (!asciiCache)
        asciiCache = new QHash<void *, QByteArray>();

    d->asciiCache = true;
    QByteArray ascii = toLatin1();
    QByteArray old = asciiCache->value(d);
    if (old == ascii)
        return old.constData();
    asciiCache->insert(d, ascii);
    return ascii.constData();
}

#endif

#ifdef Q_OS_WIN32
#include "qt_windows.h"

QByteArray qt_winQString2MB(const QString& s, int uclen)
{
    if (uclen < 0)
        uclen = s.length();
    if (s.isNull())
        return QByteArray();
    if (uclen == 0)
        return QByteArray("");
    return qt_winQString2MB(s.constData(), uclen);
}

QByteArray qt_winQString2MB(const QChar *ch, int uclen)
{
    if (!ch)
  return QByteArray();
    if (uclen == 0)
        return QByteArray("");
    BOOL used_def;
    QByteArray mb(4096, 0);
    int len;
    while (!(len=WideCharToMultiByte(CP_ACP, 0, (const WCHAR*)ch, uclen,
                mb.data(), mb.size()-1, 0, &used_def)))
    {
        int r = GetLastError();
        if (r == ERROR_INSUFFICIENT_BUFFER) {
            mb.resize(1+WideCharToMultiByte(CP_ACP, 0,
                                (const WCHAR*)ch, uclen,
                                0, 0, 0, &used_def));
                // and try again...
        } else {
#ifndef QT_NO_DEBUG
            // Fail.
            qWarning("WideCharToMultiByte: Cannot convert multibyte text (error %d): %s (UTF-8)",
                r, QString(ch, uclen).toLocal8Bit().data());
#endif
            break;
        }
    }
    mb.resize(len);
    return mb;
}

QString qt_winMB2QString(const char *mb, int mblen)
{
    if (!mb || !mblen)
        return QString();
    const int wclen_auto = 4096;
    WCHAR wc_auto[wclen_auto];
    int wclen = wclen_auto;
    WCHAR *wc = wc_auto;
    int len;
    while (!(len=MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED,
                mb, mblen, wc, wclen)))
    {
        int r = GetLastError();
        if (r == ERROR_INSUFFICIENT_BUFFER) {
            if (wc != wc_auto) {
                qWarning("MultiByteToWideChar: Size changed");
                break;
            } else {
                wclen = MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED,
                                    mb, mblen, 0, 0);
                wc = new WCHAR[wclen];
                // and try again...
            }
        } else {
            // Fail.
            qWarning("MultiByteToWideChar: Cannot convert multibyte text");
            break;
        }
    }
    if (len <= 0)
        return QString();
    if (wc[len-1] == 0) // len - 1: we don't want terminator
        --len;
    QString s((QChar*)wc, len);
    if (wc != wc_auto)
        delete [] wc;
    return s;
}
#endif // Q_OS_WIN32

QString QString::fromLocal8Bit(const char *str, int size)
{
    if (!str)
        return QString();
    if (size == 0 || (!*str && size < 0))
        return QLatin1String("");
#if defined(Q_OS_WIN32)
    if(QSysInfo::WindowsVersion & QSysInfo::WV_DOS_based) {
        return qt_winMB2QString(str, size);
    }
#endif
#if !defined(QT_NO_TEXTCODEC)
    if (size < 0)
        size = qstrlen(str);
    QTextCodec *codec = QTextCodec::codecForLocale();
    if (codec)
        return codec->toUnicode(str, size);
#endif // !QT_NO_TEXTCODEC
    return fromLatin1(str, size);
}

QString QString::fromAscii(const char *str, int size)
{
    return QString(fromAscii_helper(str, size), 0);
}

static ushort *addOne(ushort *qch, QString &str)
{
    long sidx = qch - str.utf16();
    str.resize(str.length()+1);
    return (ushort *)str.data() + sidx;
}

QString QString::fromUtf8(const char *str, int size)
{
    if (!str)
        return QString();
    if (size < 0)
        size = qstrlen(str);

    QString result;
    result.resize(size); // worst case
    ushort *qch = result.d->data;
    uint uc = 0;
    int need = 0;
    int error = -1;
    uchar ch;
    for (int i = 0; i < size; ++i) {
        ch = str[i];
        if (need) {
            if ((ch&0xc0) == 0x80) {
                uc = (uc << 6) | (ch & 0x3f);
                need--;
                if (!need) {
                    if (uc > 0xffff) {
                        // surrogate pair
                        uc -= 0x10000;
                        ushort high = uc/0x400 + 0xd800;
                        ushort low = uc%0x400 + 0xdc00;
                        *qch++ = high;
                        *qch++ = low;
                    } else {
                        *qch++ = uc;
                    }
                }
            } else {
                // See QString::toUtf8() for explanation.
                //
                // The surrogate below corresponds to a Unicode value of (0x10fe00+ch) which
                // is in one of the private use areas of Unicode.
                i = error;
                qch = addOne(qch, result);
                *qch++ = 0xdbff;
                *qch++ = 0xde00 + ((uchar)str[i]);
                need = 0;
            }
        } else {
            if (ch < 128) {
                *qch++ = ch;
            } else if ((ch & 0xe0) == 0xc0) {
                uc = ch & 0x1f;
                need = 1;
                error = i;
            } else if ((ch & 0xf0) == 0xe0) {
                uc = ch & 0x0f;
                need = 2;
                error = i;
            } else if ((ch&0xf8) == 0xf0) {
                uc = ch & 0x07;
                need = 3;
                error = i;
            } else {
                // Error
                qch = addOne(qch, result);
                *qch++ = 0xdbff;
                *qch++ = 0xde00 + ((uchar)str[i]);
            }
        }
    }
    if (need) {
        // we have some invalid characters remaining we need to add to the string
        for (int i = error; i < size; ++i) {
            qch = addOne(qch, result);
            *qch++ = 0xdbff;
            *qch++ = 0xde00 + (uchar)str[i];
        }
    }

    result.truncate(qch - result.d->data);
    return result;
}

QString QString::fromUtf16(const ushort *unicode, int size)
{
    if (!unicode)
        return QString();
    if (size < 0) {
        size = 0;
        while (unicode[size] != 0)
            ++size;
    }
    return QString((const QChar *)unicode, size);
}


QString QString::fromUcs4(const uint *unicode, int size)
{
    if (!unicode)
        return QString();
    if (size < 0) {
        size = 0;
        while (unicode[size] != 0)
            ++size;
    }

    QString s;
    s.resize(size*2); // worst case
    QChar *uc = s.data();
    for (int i = 0; i < size; ++i) {
        uint u = unicode[i];
        if (u > 0xffff) {
            // decompose into a surrogate pair
            u -= 0x10000;
            *uc = QChar(u/0x400 + 0xd800);
            ++uc;
            u = u%0x400 + 0xdc00;
        }
        *uc = QChar(u);
        ++uc;
    }
    s.resize(uc - s.data());
    return s;
}

QString& QString::setUnicode(const QChar *unicode, int size)
{
     resize(size);
     if (unicode && size)
         memcpy(d->data, unicode, size * sizeof(QChar));
     return *this;
}

QString QString::simplified() const
{
    if (d->size == 0)
        return *this;
    QString result;
    result.resize(d->size);
    const QChar *from = (const QChar*) d->data;
    const QChar *fromend = (const QChar*) from+d->size;
    int outc=0;
    QChar *to   = (QChar*) result.d->data;
    for (;;) {
        while (from!=fromend && from->isSpace())
            from++;
        while (from!=fromend && !from->isSpace())
            to[outc++] = *from++;
        if (from!=fromend)
            to[outc++] = QLatin1Char(' ');
        else
            break;
    }
    if (outc > 0 && to[outc-1] == QLatin1Char(' '))
        outc--;
    result.truncate(outc);
    return result;
}

QString QString::trimmed() const
{
    if (d->size == 0)
        return *this;
    const QChar *s = (const QChar*)d->data;
    if (!s->isSpace() && !s[d->size-1].isSpace())
        return *this;
    int start = 0;
    int end = d->size - 1;
    while (start<=end && s[start].isSpace())  // skip white space from start
        start++;
    if (start <= end) {                          // only white space
        while (end && s[end].isSpace())           // skip white space from end
            end--;
    }
    int l = end - start + 1;
    if (l <= 0) {
        shared_empty.ref.ref();
        return QString(&shared_empty, 0);
    }
    return QString(s + start, l);
}

void QString::truncate(int pos)
{
    if (pos < d->size)
        resize(pos);
}


void QString::chop(int n)
{
    if (n > 0)
        resize(d->size - n);
}

QString& QString::fill(QChar ch, int size)
{
    resize(size < 0 ? d->size : size);
    if (d->size) {
        QChar *i = (QChar*)d->data + d->size;
        QChar *b = (QChar*)d->data;
        while (i != b)
           *--i = ch;
    }
    return *this;
}

int QString::compare(const QString &other) const
{
    return ucstrcmp(*this, other);
}

int QString::compare(const QString &other, Qt::CaseSensitivity cs) const
{
    return (cs == Qt::CaseSensitive) ? ucstrcmp(*this, other) : ucstricmp(*this, other);
}

int QString::compare(const QLatin1String &other, Qt::CaseSensitivity cs) const
{
    const ushort *uc = d->data;
    const ushort *e = uc + d->size;
    const uchar *c = (uchar *)other.latin1();

    if (!c)
        return d->size;

    if (cs == Qt::CaseSensitive) {
        while (uc != e && *c && *uc == *c)
            uc++, c++;

        return *uc - *c;
    } else {
        while (uc != e && *c && QUnicodeTables::lower(*uc) == QUnicodeTables::lower(*c))
            uc++, c++;

        return QUnicodeTables::lower(*uc) - QUnicodeTables::lower(*c);
    }
}

#if !defined(CSTR_LESS_THAN)
#define CSTR_LESS_THAN    1
#define CSTR_EQUAL        2
#define CSTR_GREATER_THAN 3
#endif

int QString::localeAwareCompare(const QString &other) const
{
    // do the right thing for null and empty
    if (isEmpty() || other.isEmpty())
        return compare(other);

#if defined(Q_OS_WIN32)
    int res;
    QT_WA({
        const TCHAR* s1 = (TCHAR*)utf16();
        const TCHAR* s2 = (TCHAR*)other.utf16();
        res = CompareStringW(GetThreadLocale(), 0, s1, length(), s2, other.length());
    } , {
        QByteArray s1 = toLocal8Bit();
        QByteArray s2 = other.toLocal8Bit();
        res = CompareStringA(GetThreadLocale(), 0, s1.data(), s1.length(), s2.data(), s2.length());
    });

    switch (res) {
    case CSTR_LESS_THAN:
        return -1;
    case CSTR_GREATER_THAN:
        return 1;
    default:
        return 0;
    }
#elif defined(Q_OS_UNIX)
    // declared in <string.h>
    int delta = strcoll(toLocal8Bit(), other.toLocal8Bit());
    if (delta == 0)
        delta = ucstrcmp(*this, other);
    return delta;
#else
    return ucstrcmp(*this, other);
#endif
}


const ushort *QString::utf16() const
{
    if (d->data != d->array) {
        QString *that = const_cast<QString*>(this);
        that->realloc();   // ensure '\\0'-termination for ::fromRawData strings
        return that->d->data;
    }
    return d->array;
}

QString QString::leftJustified(int width, QChar fill, bool truncate) const
{
    QString result;
    int len = length();
    int padlen = width - len;
    if (padlen > 0) {
        result.resize(len+padlen);
        if (len)
            memcpy(result.d->data, d->data, sizeof(QChar)*len);
        QChar *uc = (QChar*)result.d->data + len;
        while (padlen--)
           * uc++ = fill;
    } else {
        if (truncate)
            result = left(width);
        else
            result = *this;
    }
    return result;
}

QString QString::rightJustified(int width, QChar fill, bool truncate) const
{
    QString result;
    int len = length();
    int padlen = width - len;
    if (padlen > 0) {
        result.resize(len+padlen);
        QChar *uc = (QChar*)result.d->data;
        while (padlen--)
           * uc++ = fill;
        if (len)
            memcpy(uc, d->data, sizeof(QChar)*len);
    } else {
        if (truncate)
            result = left(width);
        else
            result = *this;
    }
    return result;
}

QString QString::toLower() const
{
    int l = d->size;
    if (l) {
        QChar *p = (QChar*)d->data;
        if (p) {
            while (l) {
                bool different;
                if (p->unicode() & 0xFF80)
                    different = (*p != QUnicodeTables::lower(*p));
                else
                    different = ((uint)p->cell() - 'A' < 26);

                if (different) {
                    QString s(*this);
                    p = (QChar*)s.data() + (p - (QChar*)d->data);
                    while (l) {
                        *p = QUnicodeTables::lower(*p);
                        l--;
                        p++;
                    }
                    return s;
                }
                l--;
                p++;
            }
        }
    }
    return *this;
}

QString QString::toUpper() const
{
    int l = d->size;
    if (l) {
        QChar *p = (QChar*)d->data;
        if (p) {
            while (l) {
                bool different;
                if (p->unicode() & 0xFF80)
                    different = (*p != QUnicodeTables::upper(*p));
                else
                    different = ((uint)p->cell() - 'a' < 26);

                if (different) {
                    QString s(*this);
                    p = s.data() + (p - (QChar*)d->data);
                    while (l) {
                        *p = QUnicodeTables::upper(*p);
                        l--;
                        p++;
                    }
                    return s;
                }
                l--;
                p++;
            }
        }
    }
    return *this;
}


QString &QString::sprintf(const char *cformat, ...)
{
    va_list ap;
    va_start(ap, cformat);
    QString &s = vsprintf(cformat, ap);
    va_end(ap);
    return s;
}

QString &QString::vsprintf(const char* cformat, va_list ap)
{
    QLocale locale(QLocale::C);

    if (!cformat || !*cformat) {
        // Qt 1.x compat
        *this = fromLatin1("");
        return *this;
    }

    // Parse cformat

    QString result;
    const char *c = cformat;
    for (;;) {
        // Copy non-escape chars to result
        while (*c != '\0' && *c != '%')
            result.append(QLatin1Char(*c++));

        if (*c == '\0')
            break;

        // Found '%'
        const char *escape_start = c;
        ++c;

        if (*c == '\0') {
            result.append(QLatin1Char('%')); // a % at the end of the string - treat as non-escape text
            break;
        }
        if (*c == '%') {
            result.append(QLatin1Char('%')); // %%
            ++c;
            continue;
        }

        // Parse flag characters
        uint flags = 0;
        bool no_more_flags = false;
        do {
            switch (*c) {
                case '#': flags |= QLocalePrivate::Alternate; break;
                case '0': flags |= QLocalePrivate::ZeroPadded; break;
                case '-': flags |= QLocalePrivate::LeftAdjusted; break;
                case ' ': flags |= QLocalePrivate::BlankBeforePositive; break;
                case '+': flags |= QLocalePrivate::AlwaysShowSign; break;
                case '\'': flags |= QLocalePrivate::ThousandsGroup; break;
                default: no_more_flags = true; break;
            }

            if (!no_more_flags)
                ++c;
        } while (!no_more_flags);

        if (*c == '\0') {
            result.append(QLatin1String(escape_start)); // incomplete escape, treat as non-escape text
            break;
        }

        // Parse field width
        int width = -1; // -1 means unspecified
        if (qIsDigit(*c)) {
            QString width_str;
            while (*c != '\0' && qIsDigit(*c))
                width_str.append(QLatin1Char(*c++));

            // can't be negative - started with a digit
            // contains at least one digit
            width = width_str.toInt();
        }
        else if (*c == '*') {
            width = va_arg(ap, int);
            if (width < 0)
                width = -1; // treat all negative numbers as unspecified
            ++c;
        }

        if (*c == '\0') {
            result.append(QLatin1String(escape_start)); // incomplete escape, treat as non-escape text
            break;
        }

        // Parse precision
        int precision = -1; // -1 means unspecified
        if (*c == '.') {
            ++c;
            if (qIsDigit(*c)) {
                QString precision_str;
                while (*c != '\0' && qIsDigit(*c))
                    precision_str.append(QLatin1Char(*c++));

                // can't be negative - started with a digit
                // contains at least one digit
                precision = precision_str.toInt();
            }
            else if (*c == '*') {
                precision = va_arg(ap, int);
                if (precision < 0)
                    precision = -1; // treat all negative numbers as unspecified
                ++c;
            }
        }

        if (*c == '\0') {
            result.append(QLatin1String(escape_start)); // incomplete escape, treat as non-escape text
            break;
        }

        // Parse the length modifier
        enum LengthMod { lm_none, lm_hh, lm_h, lm_l, lm_ll, lm_L, lm_j, lm_z, lm_t };
        LengthMod length_mod = lm_none;
        switch (*c) {
            case 'h':
                ++c;
                if (*c == 'h') {
                    length_mod = lm_hh;
                    ++c;
                }
                else
                    length_mod = lm_h;
                break;

            case 'l':
                ++c;
                if (*c == 'l') {
                    length_mod = lm_ll;
                    ++c;
                }
                else
                    length_mod = lm_l;
                break;

            case 'L':
                ++c;
                length_mod = lm_L;
                break;

            case 'j':
                ++c;
                length_mod = lm_j;
                break;

            case 'z':
            case 'Z':
                ++c;
                length_mod = lm_z;
                break;

            case 't':
                ++c;
                length_mod = lm_t;
                break;

            default: break;
        }

        if (*c == '\0') {
            result.append(QLatin1String(escape_start)); // incomplete escape, treat as non-escape text
            break;
        }

        // Parse the conversion specifier and do the conversion
        QString subst;
        switch (*c) {
            case 'd':
            case 'i': {
                qint64 i;
                switch (length_mod) {
                    case lm_none: i = va_arg(ap, int); break;
                    case lm_hh: i = va_arg(ap, int); break;
                    case lm_h: i = va_arg(ap, int); break;
                    case lm_l: i = va_arg(ap, long int); break;
                    case lm_ll: i = va_arg(ap, qint64); break;
                    case lm_j: i = va_arg(ap, long int); break;
                    case lm_z: i = va_arg(ap, size_t); break;
                    case lm_t: i = va_arg(ap, int); break;
                    default: i = 0; break;
                }
                subst = locale.d()->longLongToString(i, precision, 10, width, flags);
                ++c;
                break;
            }
            case 'o':
            case 'u':
            case 'x':
            case 'X': {
                quint64 u;
                switch (length_mod) {
                    case lm_none: u = va_arg(ap, uint); break;
                    case lm_hh: u = va_arg(ap, uint); break;
                    case lm_h: u = va_arg(ap, uint); break;
                    case lm_l: u = va_arg(ap, ulong); break;
                    case lm_ll: u = va_arg(ap, quint64); break;
                    default: u = 0; break;
                }

                if (qIsUpper(*c))
                    flags |= QLocalePrivate::CapitalEorX;

                int base = 10;
                switch (qToLower(*c)) {
                    case 'o':
                        base = 8; break;
                    case 'u':
                        base = 10; break;
                    case 'x':
                        base = 16; break;
                    default: break;
                }
                subst = locale.d()->unsLongLongToString(u, precision, base, width, flags);
                ++c;
                break;
            }
            case 'E':
            case 'e':
            case 'F':
            case 'f':
            case 'G':
            case 'g':
            case 'A':
            case 'a': {
                double d;
                if (length_mod == lm_L)
                    d = va_arg(ap, long double); // not supported - converted to a double
                else
                    d = va_arg(ap, double);

                if (qIsUpper(*c))
                    flags |= QLocalePrivate::CapitalEorX;

                QLocalePrivate::DoubleForm form = QLocalePrivate::DFDecimal;
                switch (qToLower(*c)) {
                    case 'e': form = QLocalePrivate::DFExponent; break;
                    case 'a':                             // not supported - decimal form used instead
                    case 'f': form = QLocalePrivate::DFDecimal; break;
                    case 'g': form = QLocalePrivate::DFSignificantDigits; break;
                    default: break;
                }
                subst = locale.d()->doubleToString(d, precision, form, width, flags);
                ++c;
                break;
            }
            case 'c': {
                if (length_mod == lm_l)
                    subst = QChar((ushort) va_arg(ap, int));
                else
                    subst = QLatin1Char((uchar) va_arg(ap, int));
                ++c;
                break;
            }
            case 's': {
                if (length_mod == lm_l) {
                    const ushort *buff = va_arg(ap, const ushort*);
                    const ushort *ch = buff;
                    while (*ch != 0)
                        ++ch;
                    subst.setUtf16(buff, ch - buff);
                } else
                    subst = QString::fromUtf8(va_arg(ap, const char*));
                if (precision != -1)
                    subst.truncate(precision);
                ++c;
                break;
            }
            case 'p': {
                void *arg = va_arg(ap, void*);
#ifdef Q_OS_WIN64
                quint64 i = reinterpret_cast<quint64>(arg);
#else
                quint64 i = reinterpret_cast<unsigned long>(arg);
#endif
                flags |= QLocalePrivate::Alternate;
                subst = locale.d()->unsLongLongToString(i, precision, 16, width, flags);
                ++c;
                break;
            }
            case 'n':
                switch (length_mod) {
                    case lm_hh: {
                        signed char *n = va_arg(ap, signed char*);
                        *n = result.length();
                        break;
                    }
                    case lm_h: {
                        short int *n = va_arg(ap, short int*);
                        *n = result.length();
                            break;
                    }
                    case lm_l: {
                        long int *n = va_arg(ap, long int*);
                        *n = result.length();
                        break;
                    }
                    case lm_ll: {
                        qint64 *n = va_arg(ap, qint64*);
                        volatile uint tmp = result.length(); // egcs-2.91.66 gets internal
                        *n = tmp;                             // compiler error without volatile
                        break;
                    }
                    default: {
                        int *n = va_arg(ap, int*);
                        *n = result.length();
                        break;
                    }
                }
                ++c;
                break;

            default: // bad escape, treat as non-escape text
                for (const char *cc = escape_start; cc != c; ++cc)
                    result.append(QLatin1Char(*cc));
                continue;
        }

        if (flags & QLocalePrivate::LeftAdjusted)
            result.append(subst.leftJustified(width));
        else
            result.append(subst.rightJustified(width));
    }

    *this = result;

    return *this;
}

qint64 QString::toLongLong(bool *ok, int base) const
{
#if defined(QT_CHECK_RANGE)
    if (base != 0 && (base < 2 || base > 36)) {
        qWarning("QString::toLongLong: Invalid base (%d)", base);
        base = 10;
    }
#endif

    bool my_ok;
    QLocale def_locale;
    qint64 result = def_locale.d()->stringToLongLong(*this, base, &my_ok, QLocalePrivate::FailOnGroupSeparators);
    if (my_ok) {
        if (ok != 0)
            *ok = true;
        return result;
    }

    QLocale c_locale(QLocale::C);
    return c_locale.d()->stringToLongLong(*this, base, ok, QLocalePrivate::FailOnGroupSeparators);
}

quint64 QString::toULongLong(bool *ok, int base) const
{
#if defined(QT_CHECK_RANGE)
    if (base != 0 && (base < 2 || base > 36)) {
        qWarning("QString::toULongLong: Invalid base (%d)", base);
        base = 10;
    }
#endif

    bool my_ok;
    QLocale def_locale;
    quint64 result = def_locale.d()->stringToUnsLongLong(*this, base, &my_ok, QLocalePrivate::FailOnGroupSeparators);
    if (my_ok) {
        if (ok != 0)
            *ok = true;
        return result;
    }

    QLocale c_locale(QLocale::C);
    return c_locale.d()->stringToUnsLongLong(*this, base, ok, QLocalePrivate::FailOnGroupSeparators);
}

long QString::toLong(bool *ok, int base) const
{
    qint64 v = toLongLong(ok, base);
    if (v < LONG_MIN || v > LONG_MAX) {
        if (ok)
            *ok = false;
        v = 0;
    }
    return (long)v;
}

ulong QString::toULong(bool *ok, int base) const
{
    quint64 v = toULongLong(ok, base);
    if (v > ULONG_MAX) {
        if (ok)
            *ok = false;
        v = 0;
    }
    return (ulong)v;
}


int QString::toInt(bool *ok, int base) const
{
    qint64 v = toLongLong(ok, base);
    if (v < INT_MIN || v > INT_MAX) {
        if (ok)
            *ok = false;
        v = 0;
    }
    return v;
}

uint QString::toUInt(bool *ok, int base) const
{
    quint64 v = toULongLong(ok, base);
    if (v > UINT_MAX) {
        if (ok)
            *ok = false;
        v = 0;
    }
    return (uint)v;
}

short QString::toShort(bool *ok, int base) const
{
    long v = toLongLong(ok, base);
    if (v < SHRT_MIN || v > SHRT_MAX) {
        if (ok)
            *ok = false;
        v = 0;
    }
    return (short)v;
}

ushort QString::toUShort(bool *ok, int base) const
{
    ulong v = toULongLong(ok, base);
    if (v > USHRT_MAX) {
        if (ok)
            *ok = false;
        v = 0;
    }
    return (ushort)v;
}


double QString::toDouble(bool *ok) const
{
    bool my_ok;
    QLocale def_locale;
    double result = def_locale.d()->stringToDouble(*this, &my_ok, QLocalePrivate::FailOnGroupSeparators);
    if (my_ok) {
        if (ok != 0)
            *ok = true;
        return result;
    }

    QLocale c_locale(QLocale::C);
    return c_locale.d()->stringToDouble(*this, ok, QLocalePrivate::FailOnGroupSeparators);
}

#define QT_MAX_FLOAT 3.4028234663852886e+38

float QString::toFloat(bool *ok) const
{
    bool myOk;
    double d = toDouble(&myOk);
    if (!myOk || d > QT_MAX_FLOAT || d < -QT_MAX_FLOAT) {
        if (ok != 0)
            *ok = false;
        return 0.0;
    }
    if (ok != 0)
        *ok = true;
    return (float) d;
}

QString &QString::setNum(qlonglong n, int base)
{
#if defined(QT_CHECK_RANGE)
    if (base < 2 || base > 36) {
        qWarning("QString::setNum: Invalid base (%d)", base);
        base = 10;
    }
#endif
    QLocale locale(QLocale::C);
    *this = locale.d()->longLongToString(n, -1, base);
    return *this;
}

QString &QString::setNum(qulonglong n, int base)
{
#if defined(QT_CHECK_RANGE)
    if (base < 2 || base > 36) {
        qWarning("QString::setNum: Invalid base (%d)", base);
        base = 10;
    }
#endif
    QLocale locale(QLocale::C);
    *this = locale.d()->unsLongLongToString(n, -1, base);
    return *this;
}

QString &QString::setNum(double n, char f, int prec)
{
    QLocalePrivate::DoubleForm form = QLocalePrivate::DFDecimal;
    uint flags = 0;

    if (qIsUpper(f))
        flags = QLocalePrivate::CapitalEorX;
    f = qToLower(f);

    switch (f) {
        case 'f':
            form = QLocalePrivate::DFDecimal;
            break;
        case 'e':
            form = QLocalePrivate::DFExponent;
            break;
        case 'g':
            form = QLocalePrivate::DFSignificantDigits;
            break;
        default:
#if defined(QT_CHECK_RANGE)
            qWarning("QString::setNum: Invalid format char '%c'", f);
#endif
            break;
    }

    QLocale locale(QLocale::C);
    *this = locale.d()->doubleToString(n, prec, form, -1, flags);
    return *this;
}

QString QString::number(long n, int base)
{
    QString s;
    s.setNum(n, base);
    return s;
}

QString QString::number(ulong n, int base)
{
    QString s;
    s.setNum(n, base);
    return s;
}

QString QString::number(int n, int base)
{
    QString s;
    s.setNum(n, base);
    return s;
}

QString QString::number(uint n, int base)
{
    QString s;
    s.setNum(n, base);
    return s;
}

QString QString::number(qlonglong n, int base)
{
    QString s;
    s.setNum(n, base);
    return s;
}

QString QString::number(qulonglong n, int base)
{
    QString s;
    s.setNum(n, base);
    return s;
}


QString QString::number(double n, char f, int prec)
{
    QString s;
    s.setNum(n, f, prec);
    return s;
}

QStringList QString::split(const QString &sep, SplitBehavior behavior, Qt::CaseSensitivity cs) const
{
    QStringList list;
    int start = 0;
    int extra = 0;
    int end;
    while ((end = indexOf(sep, start + extra, cs)) != -1) {
        if (start != end || behavior == KeepEmptyParts)
            list.append(mid(start, end - start));
        start = end + sep.size();
        extra = (sep.size() == 0 ? 1 : 0);
    }
    if (start != size() || behavior == KeepEmptyParts)
        list.append(mid(start));
    return list;
}

QStringList QString::split(const QChar &sep, SplitBehavior behavior, Qt::CaseSensitivity cs) const
{
    QStringList list;
    int start = 0;
    int end;
    while ((end = indexOf(sep, start, cs)) != -1) {
        if (start != end || behavior == KeepEmptyParts)
            list.append(mid(start, end - start));
        start = end + 1;
    }
    if (start != size() || behavior == KeepEmptyParts)
        list.append(mid(start));
    return list;
}

#ifndef QT_NO_REGEXP

QStringList QString::split(const QRegExp &rx, SplitBehavior behavior) const
{
    QStringList list;
    int start = 0;
    int extra = 0;
    int end;
    while ((end = indexOf(rx, start + extra)) != -1) {
        int matchedLen = rx.matchedLength();
        if (start != end || behavior == KeepEmptyParts)
            list.append(mid(start, end - start));
        start = end + matchedLen;
        extra = (matchedLen == 0) ? 1 : 0;
    }
    if (start != size() || behavior == KeepEmptyParts)
        list.append(mid(start));
    return list;
}
#endif

QString QString::normalized(NormalizationForm form) const
{
    return QUnicodeTables::normalize(*this, form);
}

QString QString::normalized(NormalizationForm form, QChar::UnicodeVersion version) const
{
    return QUnicodeTables::normalize(*this, form, version);
}

struct ArgEscapeData
{
    int min_escape;            // lowest escape sequence number
    int occurrences;           // number of occurrences of the lowest escape sequence number
    int locale_occurrences;    // number of occurrences of the lowest escape sequence number that
                               // contain 'L'
    int escape_len;            // total length of escape sequences which will be replaced
};

static ArgEscapeData findArgEscapes(const QString &s)
{
    const QChar *uc_begin = s.unicode();
    const QChar *uc_end = uc_begin + s.length();

    ArgEscapeData d;

    d.min_escape = INT_MAX;
    d.occurrences = 0;
    d.escape_len = 0;
    d.locale_occurrences = 0;

    const QChar *c = uc_begin;
    while (c != uc_end) {
        while (c != uc_end && c->unicode() != '%')
            ++c;

        if (c == uc_end)
            break;
        const QChar *escape_start = c;
        if (++c == uc_end)
            break;

        bool locale_arg = false;
        if (c->unicode() == 'L') {
            locale_arg = true;
            if (++c == uc_end)
                break;
        }

        if (c->digitValue() == -1)
            continue;

        int escape = c->digitValue();
        ++c;

        if (c != uc_end && c->digitValue() != -1) {
            escape = (10 * escape) + c->digitValue();
            ++c;
        }

        if (escape > d.min_escape)
            continue;

        if (escape < d.min_escape) {
            d.min_escape = escape;
            d.occurrences = 0;
            d.escape_len = 0;
            d.locale_occurrences = 0;
        }

        ++d.occurrences;
        if (locale_arg)
            ++d.locale_occurrences;
        d.escape_len += c - escape_start;
    }
    return d;
}

static QString replaceArgEscapes(const QString &s, const ArgEscapeData &d, int field_width,
                                 const QString &arg, const QString &larg, const QChar &fillChar = QLatin1Char(' '))
{
    const QChar *uc_begin = s.unicode();
    const QChar *uc_end = uc_begin + s.length();

    int abs_field_width = qAbs(field_width);
    int result_len = s.length()
                     - d.escape_len
                     + (d.occurrences - d.locale_occurrences)
                     *qMax(abs_field_width, arg.length())
                     + d.locale_occurrences
                     *qMax(abs_field_width, larg.length());

    QString result;
    result.resize(result_len);
    QChar *result_buff = (QChar*) result.unicode();

    QChar *rc = result_buff;
    const QChar *c = uc_begin;
    int repl_cnt = 0;
    while (c != uc_end) {
        /* We don't have to check if we run off the end of the string with c,
           because as long as d.occurrences > 0 we KNOW there are valid escape
           sequences. */

        const QChar *text_start = c;

        while (c->unicode() != '%')
            ++c;

        const QChar *escape_start = c++;

        bool locale_arg = false;
        if (c->unicode() == 'L') {
            locale_arg = true;
            ++c;
        }

        int escape = c->digitValue();
        if (escape != -1) {
            if (c + 1 != uc_end && (c + 1)->digitValue() != -1) {
                escape = (10 * escape) + (c + 1)->digitValue();
                ++c;
            }
        }

        if (escape != d.min_escape) {
            memcpy(rc, text_start, (c - text_start)*sizeof(QChar));
            rc += c - text_start;
        }
        else {
            ++c;

            memcpy(rc, text_start, (escape_start - text_start)*sizeof(QChar));
            rc += escape_start - text_start;

            uint pad_chars;
            if (locale_arg)
                pad_chars = qMax(abs_field_width, larg.length()) - larg.length();
            else
                pad_chars = qMax(abs_field_width, arg.length()) - arg.length();

            if (field_width > 0) { // left padded
                for (uint i = 0; i < pad_chars; ++i)
                    (rc++)->unicode() = fillChar.unicode();
            }

            if (locale_arg) {
                memcpy(rc, larg.unicode(), larg.length()*sizeof(QChar));
                rc += larg.length();
            }
            else {
                memcpy(rc, arg.unicode(), arg.length()*sizeof(QChar));
                rc += arg.length();
            }

            if (field_width < 0) { // right padded
                for (uint i = 0; i < pad_chars; ++i)
                    (rc++)->unicode() = fillChar.unicode();
            }

            if (++repl_cnt == d.occurrences) {
                memcpy(rc, c, (uc_end - c)*sizeof(QChar));
                rc += uc_end - c;
                Q_ASSERT(rc - result_buff == result_len);
                c = uc_end;
            }
        }
    }
    Q_ASSERT(rc == result_buff + result_len);

    return result;
}

QString QString::arg(const QString &a, int fieldWidth, const QChar &fillChar) const
{
    ArgEscapeData d = findArgEscapes(*this);

    if (d.occurrences == 0) {
        qWarning("QString::arg: Argument missing: %s, %s", toLocal8Bit().data(),
                  a.toLocal8Bit().data());
        return *this;
    }
    return replaceArgEscapes(*this, d, fieldWidth, a, a, fillChar);
}

QString QString::arg(qlonglong a, int fieldWidth, int base, const QChar &fillChar) const
{
    ArgEscapeData d = findArgEscapes(*this);

    if (d.occurrences == 0) {
        qWarning("QString::arg: Argument missing: %s, %lld", toLocal8Bit().data(), a);
        return *this;
    }

    QString arg;
    if (d.occurrences > d.locale_occurrences)
        arg = number(a, base);

    QString locale_arg;
    if (d.locale_occurrences > 0) {
        QLocale locale;
        locale_arg = locale.d()->longLongToString(a, -1, base, -1, QLocalePrivate::ThousandsGroup);
    }

    return replaceArgEscapes(*this, d, fieldWidth, arg, locale_arg, fillChar);
}

QString QString::arg(qulonglong a, int fieldWidth, int base, const QChar &fillChar) const
{
    ArgEscapeData d = findArgEscapes(*this);

    if (d.occurrences == 0) {
        qWarning("QString::arg: Argument missing: %s, %llu", toLocal8Bit().data(), a);
        return *this;
    }

    QString arg;
    if (d.occurrences > d.locale_occurrences)
        arg = number(a, base);

    QString locale_arg;
    if (d.locale_occurrences > 0) {
        QLocale locale;
        locale_arg = locale.d()->unsLongLongToString(a, -1, base, -1, QLocalePrivate::ThousandsGroup);
    }

    return replaceArgEscapes(*this, d, fieldWidth, arg, locale_arg, fillChar);
}

QString QString::arg(QChar a, int fieldWidth, const QChar &fillChar) const
{
    QString c;
    c += a;
    return arg(c, fieldWidth, fillChar);
}

QString QString::arg(char a, int fieldWidth, const QChar &fillChar) const
{
    QString c;
    c += QLatin1Char(a);
    return arg(c, fieldWidth, fillChar);
}

QString QString::arg(double a, int fieldWidth, char fmt, int prec, const QChar &fillChar) const
{
    ArgEscapeData d = findArgEscapes(*this);

    if (d.occurrences == 0) {
        qWarning("QString::arg: Argument missing: %s, %g", toLocal8Bit().data(), a);
        return *this;
    }

    QString arg;
    if (d.occurrences > d.locale_occurrences)
        arg = number(a, fmt, prec);

    QString locale_arg;
    if (d.locale_occurrences > 0) {
        QLocale locale;

        QLocalePrivate::DoubleForm form = QLocalePrivate::DFDecimal;
        uint flags = 0;

        if (qIsUpper(fmt))
            flags = QLocalePrivate::CapitalEorX;
        fmt = qToLower(fmt);

        switch (fmt) {
            case 'f':
                form = QLocalePrivate::DFDecimal;
                break;
            case 'e':
                form = QLocalePrivate::DFExponent;
                break;
            case 'g':
                form = QLocalePrivate::DFSignificantDigits;
                break;
            default:
#if defined(QT_CHECK_RANGE)
                qWarning("QString::arg: Invalid format char '%c'", fmt);
#endif
                break;
        }

        flags |= QLocalePrivate::ThousandsGroup;

        locale_arg = locale.d()->doubleToString(a, prec, form, -1, flags);
    }

    return replaceArgEscapes(*this, d, fieldWidth, arg, locale_arg, fillChar);
}


QString QString::multiArg(int numArgs, const QString **args) const
{
    QString result;
    union {
        int digitUsed[10];
        int argForDigit[10];
    };
    const QChar *uc = (const QChar*) d->data;
    const int len = d->size;
    const int end = len - 1;
    int lastDigit = -1;
    int i;

    memset(digitUsed, 0, sizeof(digitUsed));

    for (i = 0; i < end; i++) {
        if (uc[i] == QLatin1Char('%')) {
            int digit = uc[i + 1].unicode() - '0';
            if (digit >= 0 && digit <= 9)
                digitUsed[digit]++;
        }
    }

    for (i = 0; i < numArgs; i++) {
        do {
            ++lastDigit;
        } while (lastDigit < 10 && digitUsed[lastDigit] == 0);

        if (lastDigit == 10) {
            qWarning("QString::arg: Argument missing: %s, %s", toLocal8Bit().data(), args[i]->toLocal8Bit().data());
            numArgs = i;
            lastDigit = 9;
            break;
        }
        argForDigit[lastDigit] = i;
    }

    i = 0;
    while (i < len) {
        if (uc[i] == QLatin1Char('%') && i != end) {
            int digit = uc[i + 1].unicode() - '0';
            if (digit >= 0 && digit <= lastDigit) {
                result += *args[argForDigit[digit]];
                i += 2;
                continue;
            }
        }
        result += uc[i++];
    }
    return result;
}



void QString::updateProperties() const
{
    ushort *p = d->data;
    ushort *end = p + d->size;
    d->simpletext = true;
    while (p < end) {
        ushort uc = *p;
        // sort out regions of complex text formatting
        if (uc > 0x058f && (uc < 0x1100 || uc > 0xfb0f)) {
            d->simpletext = false;
        }
        p++;
    }

    p = d->data;
    d->righttoleft = false;
    while (p < end) {
        switch(QUnicodeTables::direction(*p))
        {
        case QChar::DirL:
        case QChar::DirLRO:
        case QChar::DirLRE:
            goto end;
        case QChar::DirR:
        case QChar::DirAL:
        case QChar::DirRLO:
        case QChar::DirRLE:
            d->righttoleft = true;
            goto end;
        default:
            break;
        }
        ++p;
    }
 end:
    d->clean = true;
    return;
}

QString QString::fromRawData(const QChar *unicode, int size)
{
    Data *x = static_cast<Data *>(qMalloc(sizeof(Data)));
    if (unicode) {
        x->data = (ushort *)unicode;
    } else {
        x->data = x->array;
        size = 0;
    }
    x->ref.init(1);
    x->alloc = x->size = size;
    *x->array = '\0';
    x->clean = x->asciiCache = x->simpletext = x->righttoleft = 0;
    return QString(x, 0);
}

#ifndef QT_NO_DATASTREAM

QDataStream &operator<<(QDataStream &out, const QString &str)
{
    if (out.version() == 1) {
        out << str.toLatin1();
    } else {
        if (!str.isNull() || out.version() < 3) {
            int byteOrder = out.byteOrder();
            const QChar* ub = str.unicode();
            static const uint auto_size = 1024;
            char t[auto_size];
            char *b;
            if (str.length()*sizeof(QChar) > auto_size) {
                b = new char[str.length()*sizeof(QChar)];
            } else {
                b = t;
            }
            int l = str.length();
            char *c=b;
            while (l--) {
                if (byteOrder == QDataStream::BigEndian) {
                    *c++ = (char)ub->row();
                    *c++ = (char)ub->cell();
                } else {
                    *c++ = (char)ub->cell();
                    *c++ = (char)ub->row();
                }
                ub++;
            }
            out.writeBytes(b, sizeof(QChar)*str.length());
            if (str.length()*sizeof(QChar) > auto_size)
                delete [] b;
        } else {
            // write null marker
            out << (quint32)0xffffffff;
        }
    }
    return out;
}

QDataStream &operator>>(QDataStream &in, QString &str)
{
#ifdef QT_QSTRING_UCS_4
#if defined(Q_CC_GNU)
#warning "operator>> not working properly"
#endif
#endif

    if (in.version() == 1) {
        QByteArray l;
        in >> l;
        str = QString::fromLatin1(l);
    } else {
        quint32 bytes = 0;
        in >> bytes;                                  // read size of string
        if (bytes == 0xffffffff) {                    // null string
            str.clear();
        } else if (bytes > 0) {                       // not empty
            if (bytes & 0x1) {
                str.clear();
                in.setStatus(QDataStream::ReadCorruptData);
                return in;
            }

            const quint32 Step = 1024 * 1024;
            quint32 len = bytes / 2;
            quint32 allocated = 0;

            while (allocated < len) {
                int blockSize = qMin(Step, len - allocated);
                str.resize(allocated + blockSize);
                if (in.readRawData(reinterpret_cast<char *>(str.data()) + allocated * 2,
                                   blockSize * 2) != blockSize * 2) {
                    str.clear();
                    in.setStatus(QDataStream::ReadPastEnd);
                    return in;
                }
                allocated += blockSize;
            }

            if ((in.byteOrder() == QDataStream::BigEndian)
                    != (QSysInfo::ByteOrder == QSysInfo::BigEndian)) {
                ushort *data = reinterpret_cast<ushort *>(str.data());
                while (len--) {
                    *data = (*data >> 8) | (*data << 8);
                    ++data;
                }
            }
        } else {
            str = QLatin1String("");
        }
    }
    return in;
}
#endif // QT_NO_DATASTREAM

---