diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp
index b2c8fea5a..3076134e8 100644
--- a/src/gui/image/qimage.cpp
+++ b/src/gui/image/qimage.cpp
@@ -3871,7 +3871,7 @@ template<class T> inline void do_mirror_data(QImageData *dst, QImageData *src,
                                              int w, int h)
 {
     for (int srcY = 0, dstY = dstY0; srcY < h; ++srcY, dstY += dstYIncr) {
-        T *srcPtr = (T *) (src->data + srcY * src->bytes_per_line);
+        const T *srcPtr = (const T *) (src->data + srcY * src->bytes_per_line);
         T *dstPtr = (T *) (dst->data + dstY * dst->bytes_per_line);
         for (int srcX = 0, dstX = dstX0; srcX < w; ++srcX, dstX += dstXIncr)
             dstPtr[dstX] = srcPtr[srcX];
diff --git a/src/plugins/sqldrivers/mysql/qsql_mysql.cpp b/src/plugins/sqldrivers/mysql/qsql_mysql.cpp
index 1ef2a1397..648873caa 100644
--- a/src/plugins/sqldrivers/mysql/qsql_mysql.cpp
+++ b/src/plugins/sqldrivers/mysql/qsql_mysql.cpp
@@ -586,7 +586,7 @@ bool QMYSQLResult::fetchFirst()
     return fetch(0);
 }
 
-QVariant QMYSQLResult::data(int field)
+QVariant QMYSQLResult::data(int field) const
 {
 
     if (!isSelect() || field >= d->fields.count()) {
@@ -675,7 +675,7 @@ QVariant QMYSQLResult::data(int field)
     return QVariant();
 }
 
-bool QMYSQLResult::isNull(int field)
+bool QMYSQLResult::isNull(int field) const
 {
    if (d->preparedQuery)
        return d->fields.at(field).nullIndicator;
@@ -720,7 +720,7 @@ bool QMYSQLResult::reset (const QString& query)
     return isActive();
 }
 
-int QMYSQLResult::size()
+int QMYSQLResult::size() const
 {
     if (d->driver && isSelect())
         if (d->preparedQuery)
@@ -735,7 +735,7 @@ int QMYSQLResult::size()
         return -1;
 }
 
-int QMYSQLResult::numRowsAffected()
+int QMYSQLResult::numRowsAffected() const
 {
     return d->rowsAffected;
 }
diff --git a/src/plugins/sqldrivers/mysql/qsql_mysql.h b/src/plugins/sqldrivers/mysql/qsql_mysql.h
index f71f4e878..f17e75278 100644
--- a/src/plugins/sqldrivers/mysql/qsql_mysql.h
+++ b/src/plugins/sqldrivers/mysql/qsql_mysql.h
@@ -73,11 +73,11 @@ protected:
     bool fetchNext();
     bool fetchLast();
     bool fetchFirst();
-    QVariant data(int field);
-    bool isNull(int field);
+    QVariant data(int field) const;
+    bool isNull(int field) const;
     bool reset (const QString& query);
-    int size();
-    int numRowsAffected();
+    int size() const;
+    int numRowsAffected() const;
     QVariant lastInsertId() const;
     QSqlRecord record() const;
     void virtual_hook(int id, void *data);
diff --git a/src/plugins/sqldrivers/odbc/qsql_odbc.cpp b/src/plugins/sqldrivers/odbc/qsql_odbc.cpp
index d43b04130..32aed4780 100644
--- a/src/plugins/sqldrivers/odbc/qsql_odbc.cpp
+++ b/src/plugins/sqldrivers/odbc/qsql_odbc.cpp
@@ -1088,7 +1088,7 @@ bool QODBCResult::fetchLast()
     return true;
 }
 
-QVariant QODBCResult::data(int field)
+QVariant QODBCResult::data(int field) const
 {
     if (field >= d->rInf.count() || field < 0) {
         qWarning() << "QODBCResult::data: column" << field << "out of range";
@@ -1188,7 +1188,7 @@ QVariant QODBCResult::data(int field)
     return d->fieldCache[field];
 }
 
-bool QODBCResult::isNull(int field)
+bool QODBCResult::isNull(int field) const
 {
     if (field < 0 || field > d->fieldCache.size())
         return true;
@@ -1201,12 +1201,12 @@ bool QODBCResult::isNull(int field)
     return d->fieldCache.at(field).isNull();
 }
 
-int QODBCResult::size()
+int QODBCResult::size() const
 {
     return -1;
 }
 
-int QODBCResult::numRowsAffected()
+int QODBCResult::numRowsAffected() const
 {
     SQLLEN affectedRowCount = 0;
     SQLRETURN r = SQLRowCount(d->hStmt, &affectedRowCount);
diff --git a/src/plugins/sqldrivers/odbc/qsql_odbc.h b/src/plugins/sqldrivers/odbc/qsql_odbc.h
index 0e32d9b84..92f9762a8 100644
--- a/src/plugins/sqldrivers/odbc/qsql_odbc.h
+++ b/src/plugins/sqldrivers/odbc/qsql_odbc.h
@@ -78,10 +78,10 @@ protected:
     bool fetchPrevious();
     bool fetch(int i);
     bool reset (const QString& query);
-    QVariant data(int field);
-    bool isNull(int field);
-    int size();
-    int numRowsAffected();
+    QVariant data(int field) const;
+    bool isNull(int field) const;
+    int size() const;
+    int numRowsAffected() const;
     QSqlRecord record() const;
     void virtual_hook(int id, void *data);
     bool nextResult();
diff --git a/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp b/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp
index 9c71783b1..b921be3cd 100644
--- a/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp
+++ b/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp
@@ -456,12 +456,12 @@ bool QSQLiteResult::gotoNext(QSqlCachedResult::ValueCache& row, int idx)
     return d->fetchNext(row, idx, false);
 }
 
-int QSQLiteResult::size()
+int QSQLiteResult::size() const
 {
     return -1;
 }
 
-int QSQLiteResult::numRowsAffected()
+int QSQLiteResult::numRowsAffected() const
 {
     return sqlite3_changes(d->access);
 }
diff --git a/src/plugins/sqldrivers/sqlite/qsql_sqlite.h b/src/plugins/sqldrivers/sqlite/qsql_sqlite.h
index fafd09e69..18dec286e 100644
--- a/src/plugins/sqldrivers/sqlite/qsql_sqlite.h
+++ b/src/plugins/sqldrivers/sqlite/qsql_sqlite.h
@@ -67,8 +67,8 @@ protected:
     bool reset(const QString &query);
     bool prepare(const QString &query);
     bool exec();
-    int size();
-    int numRowsAffected();
+    int size() const;
+    int numRowsAffected() const;
     QVariant lastInsertId() const;
     QSqlRecord record() const;
     void virtual_hook(int id, void *data);
diff --git a/src/sql/kernel/qsqlfield.cpp b/src/sql/kernel/qsqlfield.cpp
index d029da3de..1d14be061 100644
--- a/src/sql/kernel/qsqlfield.cpp
+++ b/src/sql/kernel/qsqlfield.cpp
@@ -84,15 +84,15 @@ public:
 
     QAtomicInt ref;
     QString nm;
-    uint ro: 1;
+    bool ro;
     QVariant::Type type;
     QSqlField::RequiredStatus req;
     int len;
     int prec;
     QVariant def;
     int tp;
-    uint gen: 1;
-    uint autoval: 1;
+    bool gen;
+    bool autoval;
 };
 
 
@@ -241,6 +241,8 @@ void QSqlField::setRequiredStatus(RequiredStatus required)
 */
 void QSqlField::setLength(int fieldLength)
 {
+    if (d->len == fieldLength)
+        return;
     detach();
     d->len = fieldLength;
 }
@@ -252,6 +254,8 @@ void QSqlField::setLength(int fieldLength)
 */
 void QSqlField::setPrecision(int precision)
 {
+    if (d->prec == precision)
+        return;
     detach();
     d->prec = precision;
 }
@@ -263,6 +267,8 @@ void QSqlField::setPrecision(int precision)
 */
 void QSqlField::setDefaultValue(const QVariant &value)
 {
+    if (d->def == value)
+        return;
     detach();
     d->def = value;
 }
@@ -272,6 +278,8 @@ void QSqlField::setDefaultValue(const QVariant &value)
 */
 void QSqlField::setSqlType(int type)
 {
+    if (d->tp = type)
+        return;
     detach();
     d->tp = type;
 }
@@ -286,6 +294,8 @@ void QSqlField::setSqlType(int type)
 */
 void QSqlField::setGenerated(bool gen)
 {
+    if (d->gen == gen)
+        return;
     detach();
     d->gen = gen;
 }
@@ -334,6 +344,8 @@ void QSqlField::clear()
 
 void QSqlField::setName(const QString& name)
 {
+    if (d->nm == name)
+        return;
     detach();
     d->nm = name;
 }
@@ -345,6 +357,8 @@ void QSqlField::setName(const QString& name)
 */
 void QSqlField::setReadOnly(bool readOnly)
 {
+    if (d->ro == readOnly)
+        return;
     detach();
     d->ro = readOnly;
 }
@@ -388,6 +402,8 @@ QVariant::Type QSqlField::type() const
 */
 void QSqlField::setType(QVariant::Type type)
 {
+    if (d->type == type)
+        return;
     detach();
     d->type = type;
     if (!val.isValid())
@@ -553,6 +569,8 @@ bool QSqlField::isAutoValue() const
  */
 void QSqlField::setAutoValue(bool autoVal)
 {
+    if (d->autoval == autoVal)
+        return;
     detach();
     d->autoval = autoVal;
 }
diff --git a/src/sql/kernel/qsqlnulldriver_p.h b/src/sql/kernel/qsqlnulldriver_p.h
index e7e6553cd..9e3c158f1 100644
--- a/src/sql/kernel/qsqlnulldriver_p.h
+++ b/src/sql/kernel/qsqlnulldriver_p.h
@@ -59,14 +59,14 @@ public:
     { QSqlResult::setLastError(
             QSqlError(QLatin1String("Driver not loaded"), QLatin1String("Driver not loaded"), QSqlError::ConnectionError)); }
 protected:
-    inline QVariant data(int) { return QVariant(); }
+    inline QVariant data(int) const { return QVariant(); }
     inline bool reset (const QString&) { return false; }
     inline bool fetch(int) { return false; }
     inline bool fetchFirst() { return false; }
     inline bool fetchLast() { return false; }
-    inline bool isNull(int) { return false; }
-    inline int size()  { return -1; }
-    inline int numRowsAffected() { return 0; }
+    inline bool isNull(int) const { return false; }
+    inline int size() const { return -1; }
+    inline int numRowsAffected() const { return 0; }
 
     inline void setAt(int) {}
     inline void setActive(bool) {}
diff --git a/src/sql/kernel/qsqlresult.cpp b/src/sql/kernel/qsqlresult.cpp
index 5d10f7890..ff5fe1631 100644
--- a/src/sql/kernel/qsqlresult.cpp
+++ b/src/sql/kernel/qsqlresult.cpp
@@ -317,7 +317,7 @@ bool QSqlResult::isValid() const
 }
 
 /*!
-    \fn bool QSqlResult::isNull(int index)
+    \fn bool QSqlResult::isNull(int index) const
 
     Returns true if the field at position \a index in the current row
     is null; otherwise returns false.
@@ -421,7 +421,7 @@ QSqlError QSqlResult::lastError() const
 }
 
 /*!
-    \fn int QSqlResult::size()
+    \fn int QSqlResult::size() const
 
     Returns the size of the \c SELECT result, or -1 if it cannot be
     determined or if the query is not a \c SELECT statement.
@@ -430,7 +430,7 @@ QSqlError QSqlResult::lastError() const
 */
 
 /*!
-    \fn int QSqlResult::numRowsAffected()
+    \fn int QSqlResult::numRowsAffected() const
 
     Returns the number of rows affected by the last query executed, or
     -1 if it cannot be determined or if the query is a \c SELECT
@@ -440,7 +440,7 @@ QSqlError QSqlResult::lastError() const
 */
 
 /*!
-    \fn QVariant QSqlResult::data(int index)
+    \fn QVariant QSqlResult::data(int index) const
 
     Returns the data for field \a index in the current row as
     a QVariant. This function is only called if the result is in
diff --git a/src/sql/kernel/qsqlresult.h b/src/sql/kernel/qsqlresult.h
index ed5dd303f..ad8158249 100644
--- a/src/sql/kernel/qsqlresult.h
+++ b/src/sql/kernel/qsqlresult.h
@@ -104,16 +104,16 @@ protected:
 
     BindingSyntax bindingSyntax() const;
 
-    virtual QVariant data(int i) = 0;
-    virtual bool isNull(int i) = 0;
+    virtual QVariant data(int i) const = 0;
+    virtual bool isNull(int i) const = 0;
     virtual bool reset(const QString& sqlquery) = 0;
     virtual bool fetch(int i) = 0;
     virtual bool fetchNext();
     virtual bool fetchPrevious();
     virtual bool fetchFirst() = 0;
     virtual bool fetchLast() = 0;
-    virtual int size() = 0;
-    virtual int numRowsAffected() = 0;
+    virtual int size() const = 0;
+    virtual int numRowsAffected() const = 0;
     virtual QSqlRecord record() const;
     virtual QVariant lastInsertId() const;