diff options
| -rw-r--r-- | src/corelib/tools/qstring.cpp | 30 | ||||
| -rw-r--r-- | src/corelib/tools/qstring.h | 3 | ||||
| -rw-r--r-- | tests/auto/corelib/tools/qstring/tst_qstring.cpp | 8 |
3 files changed, 40 insertions, 1 deletions
diff --git a/src/corelib/tools/qstring.cpp b/src/corelib/tools/qstring.cpp index 1b07e31c89..18c96c0b38 100644 --- a/src/corelib/tools/qstring.cpp +++ b/src/corelib/tools/qstring.cpp @@ -4020,6 +4020,36 @@ QByteArray QString::toLatin1_helper(const QChar *data, int length) return ba; } +QByteArray QString::toLatin1_helper_inplace(QString &s) +{ + if (!s.isDetached()) + return s.toLatin1(); + + // We can return our own buffer to the caller. + // Conversion to Latin-1 always shrinks the buffer by half. + const ushort *data = reinterpret_cast<const ushort *>(s.constData()); + uint length = s.size(); + + // Swap the d pointers. + // Kids, avert your eyes. Don't try this at home. + QArrayData *ba_d = s.d; + + // multiply the allocated capacity by sizeof(ushort) + ba_d->alloc *= sizeof(ushort); + + // reset ourselves to QString() + s.d = QString().d; + + // do the in-place conversion + uchar *dst = reinterpret_cast<uchar *>(ba_d->data()); + QT_PREPEND_NAMESPACE(toLatin1_helper)(dst, data, length); + dst[length] = '\0'; + + QByteArrayDataPtr badptr = { ba_d }; + return QByteArray(badptr); +} + + /*! \fn QByteArray QString::toLatin1() const diff --git a/src/corelib/tools/qstring.h b/src/corelib/tools/qstring.h index 943d7c266e..460afb00f4 100644 --- a/src/corelib/tools/qstring.h +++ b/src/corelib/tools/qstring.h @@ -481,7 +481,7 @@ public: QByteArray toLatin1() const & Q_REQUIRED_RESULT { return toLatin1_helper(*this); } QByteArray toLatin1() && Q_REQUIRED_RESULT - { return toLatin1_helper(reinterpret_cast<const ushort *>(constData()), size()); } + { return toLatin1_helper_inplace(*this); } QByteArray toUtf8() const & Q_REQUIRED_RESULT { return toUtf8_helper(*this); } QByteArray toUtf8() && Q_REQUIRED_RESULT @@ -751,6 +751,7 @@ private: static QString fromLocal8Bit_helper(const char *, int size); static QByteArray toLatin1_helper(const QString &); static QByteArray toLatin1_helper(const QChar *data, int size); + static QByteArray toLatin1_helper_inplace(QString &); static QByteArray toUtf8_helper(const QString &); static QByteArray toLocal8Bit_helper(const QChar *data, int size); static int toUcs4_helper(const ushort *uc, int length, uint *out); diff --git a/tests/auto/corelib/tools/qstring/tst_qstring.cpp b/tests/auto/corelib/tools/qstring/tst_qstring.cpp index 9a3aaebaaf..a0edc16718 100644 --- a/tests/auto/corelib/tools/qstring/tst_qstring.cpp +++ b/tests/auto/corelib/tools/qstring/tst_qstring.cpp @@ -3882,6 +3882,14 @@ void tst_QString::toLatin1Roundtrip() // and back: QCOMPARE(QString::fromLatin1(latin1, latin1.length()).length(), unicodedst.length()); QCOMPARE(QString::fromLatin1(latin1, latin1.length()), unicodedst); + + // try the rvalue version of toLatin1() + QString s = unicodesrc; + QCOMPARE(qMove(s).toLatin1(), latin1); + + // and verify that the moved-from object can still be used + s = "foo"; + s.clear(); } void tst_QString::stringRef_toLatin1Roundtrip_data() |