QSqlResult: remove bad API returning non-const reference

QSqlResult::boundValues is a const member function, but returned a non-
const reference to a QList<QVariant>. This is a bad and potentially
dangerous API, as callers can modify the list stored in QSqlResult.

Move that API into the removed_api translation unit, remove it from
Qt 6.6 on and replace it with two suitable overloads where the const
version returns a QVariantList by value, and the non-const overload
returns a mutable reference.

Driver implementations that used to call the const overload to get a
mutable reference are now calling the non-const overload instead
(those calls are all made in the non-const exec() or equivalent driver
implementations).

As a drive-by, replace "vector" with "list" in the documentation.

Pick-to: 6.6
Change-Id: I6e4fd8f5749b939cdb609bf5876735e9b30b2b5a
Reviewed-by: Marc Mutz <[email protected]>

3 files changed, 37 insertions, 9 deletions

diff --git a/src/sql/compat/removed_api.cpp b/src/sql/compat/removed_api.cpp
index ff223b9967b..9da60eceda0 100644
--- a/src/sql/compat/removed_api.cpp
+++ b/src/sql/compat/removed_api.cpp
@@ -9,10 +9,6 @@ QT_USE_NAMESPACE
 
 #if QT_SQL_REMOVED_SINCE(6, 4)
 
-// #include <qotherheader.h>
-// // implement removed functions from qotherheader.h
-// order sections alphabetically to reduce chances of merge conflicts
-
 #endif // QT_SQL_REMOVED_SINCE(6, 4)
 
 #if QT_SQL_REMOVED_SINCE(6, 5)
@@ -36,8 +32,21 @@ void QSqlTableModel::setQuery(const QSqlQuery &query)
 
 #endif // QT_CONFIG(sqlmodel)
 
+#endif // QT_SQL_REMOVED_SINCE(6, 5)
+
+#if QT_SQL_REMOVED_SINCE(6, 6)
+
+#include "qsqlresult.h"
+#include <QtSql/private/qsqlresult_p.h>
+
 // #include <qotherheader.h>
 // // implement removed functions from qotherheader.h
 // order sections alphabetically to reduce chances of merge conflicts
 
-#endif // QT_SQL_REMOVED_SINCE(6, 5)
+QList<QVariant> &QSqlResult::boundValues() const
+{
+    Q_D(const QSqlResult);
+    return const_cast<QSqlResultPrivate *>(d)->values;
+}
+
+#endif // QT_SQL_REMOVED_SINCE(6, 6)
diff --git a/src/sql/kernel/qsqlresult.cpp b/src/sql/kernel/qsqlresult.cpp
index 1b7daa8d0f6..aa3608fb8cc 100644
--- a/src/sql/kernel/qsqlresult.cpp
+++ b/src/sql/kernel/qsqlresult.cpp
@@ -784,18 +784,33 @@ int QSqlResult::boundValueCount() const
 }
 
 /*!
-    Returns a vector of the result's bound values for the current
+    Returns a list of the result's bound values for the current
     record (row).
 
     \sa boundValueCount()
 */
-QList<QVariant> &QSqlResult::boundValues() const
+QVariantList QSqlResult::boundValues(QT6_IMPL_NEW_OVERLOAD) const
 {
     Q_D(const QSqlResult);
-    return const_cast<QSqlResultPrivate *>(d)->values;
+    return d->values;
 }
 
 /*!
+    \overload
+
+    Returns a mutable reference to the list of the result's bound values
+    for the current record (row).
+
+    \sa boundValueCount()
+*/
+QVariantList &QSqlResult::boundValues(QT6_IMPL_NEW_OVERLOAD)
+{
+    Q_D(QSqlResult);
+    return d->values;
+}
+
+
+/*!
     Returns the binding syntax used by prepared queries.
 */
 QSqlResult::BindingSyntax QSqlResult::bindingSyntax() const
diff --git a/src/sql/kernel/qsqlresult.h b/src/sql/kernel/qsqlresult.h
index c16564a5162..1135caf7651 100644
--- a/src/sql/kernel/qsqlresult.h
+++ b/src/sql/kernel/qsqlresult.h
@@ -69,8 +69,12 @@ protected:
     QSql::ParamType bindValueType(const QString& placeholder) const;
     QSql::ParamType bindValueType(int pos) const;
     int boundValueCount() const;
-    // ### Qt 7 - don't return a non-const reference from a const function
+#if QT_SQL_REMOVED_SINCE(6, 6)
     QList<QVariant> &boundValues() const;
+#endif
+    QVariantList &boundValues(QT6_DECL_NEW_OVERLOAD);
+    QVariantList boundValues(QT6_DECL_NEW_OVERLOAD) const;
+
     QString executedQuery() const;
     QStringList boundValueNames() const;
     QString boundValueName(int pos) const;