Add move special member functions to QSqlError

Also mark as shared-come-qt6 and add member-swap.

[ChangeLog][QtSql][QSqlError] Added swap().

Coverity-Id: 168223
Change-Id: Iaad4dee383900b9d11856e860b0647780a81a505
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

src/sql/kernel/qsqlerror.cpp

@@ -98,6 +98,34 @@ public:
     type \a type and the optional error number \a number.
 */
 
+/*! \fn QSqlError::QSqlError(QSqlError &&other)
+    Move-constructs a QSqlError instance, making it point at the same
+    object that \a other was pointing to.
+
+    \note The moved-from object \a other is placed in a
+    partially-formed state, in which the only valid operations are
+    destruction and assignment of a new value.
+
+    \since 5.10
+*/
+
+/*! \fn QSqlError::operator=(QSqlError &&other)
+    Move-assigns \a other to this QSqlError instance.
+
+    \note The moved-from object \a other is placed in a
+    partially-formed state, in which the only valid operations are
+    destruction and assignment of a new value.
+
+    \since 5.10
+*/
+
+/*! \fn QSqlError::swap(QSqlError &other)
+    Swaps error \other with this error. This operation is very fast
+    and never fails.
+
+    \since 5.10
+*/
+
 #if QT_DEPRECATED_SINCE(5, 3)
 QSqlError::QSqlError(const QString& driverText, const QString& databaseText, ErrorType type,
                     int number)
@@ -117,7 +145,6 @@ QSqlError::QSqlError(const QString& driverText, const QString& databaseText, Err
     driverText, the database-specific error text \a databaseText, the
     type \a type and the error code \a code.
 */
-
 QSqlError::QSqlError(const QString &driverText, const QString &databaseText,
                      ErrorType type, const QString &code)
 {
@@ -146,7 +173,10 @@ QSqlError::QSqlError(const QSqlError& other)
 
 QSqlError& QSqlError::operator=(const QSqlError& other)
 {
-    *d = *other.d;
+    if (d)
+        *d = *other.d;
+    else
+        d = new QSqlErrorPrivate(*other.d);
     return *this;
 }
 

src/sql/kernel/qsqlerror.h

@@ -66,11 +66,16 @@ public:
               ErrorType type = NoError,
               const QString &errorCode = QString());
     QSqlError(const QSqlError& other);
+    QSqlError(QSqlError &&other) Q_DECL_NOTHROW : d(other.d) { other.d = nullptr; }
     QSqlError& operator=(const QSqlError& other);
+    QSqlError &operator=(QSqlError &&other) Q_DECL_NOTHROW { swap(other); return *this; }
+
     bool operator==(const QSqlError& other) const;
     bool operator!=(const QSqlError& other) const;
     ~QSqlError();
 
+    void swap(QSqlError &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+
     QString driverText() const;
     QString databaseText() const;
     ErrorType type() const;
@@ -102,6 +107,8 @@ private:
     };
 };
 
+Q_DECLARE_SHARED_NOT_MOVABLE_UNTIL_QT6(QSqlError)
+
 #ifndef QT_NO_DEBUG_STREAM
 Q_SQL_EXPORT QDebug operator<<(QDebug, const QSqlError &);
 #endif

tests/auto/sql/kernel/qsqlerror/tst_qsqlerror.cpp

@@ -44,6 +44,7 @@ public:
 private slots:
     void getSetCheck();
     void construction();
+    void moveOperator();
     void operators();
 };
 
@@ -143,6 +144,26 @@ void tst_QSqlError::construction()
    QCOMPARE(obj7.number(), -1);
    QCOMPARE(obj7.nativeErrorCode(), QString());
 
+   // Move constructor
+   QSqlError obj8(std::move(obj3));
+   QCOMPARE(obj8.driverText(), obj2.driverText());
+   QCOMPARE(obj8.databaseText(), obj2.databaseText());
+   QCOMPARE(obj8.type(), obj2.type());
+   QCOMPARE(obj8.number(), obj2.number());
+   QCOMPARE(obj8.nativeErrorCode(), obj2.nativeErrorCode());
+   QVERIFY(obj8.isValid());
+}
+
+void tst_QSqlError::moveOperator()
+{
+   QSqlError obj1("drivertext", "databasetext", QSqlError::UnknownError, 123), obj2;
+   obj2 = std::move(obj1);
+   QCOMPARE(obj2.driverText(), QString("drivertext"));
+   QCOMPARE(obj2.databaseText(), QString("databasetext"));
+   QCOMPARE(obj2.type(), QSqlError::UnknownError);
+   QCOMPARE(obj2.number(), 123);
+   QCOMPARE(obj2.nativeErrorCode(), QStringLiteral("123"));
+   QVERIFY(obj2.isValid());
 }
 
 void tst_QSqlError::operators()