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 <marc.mutz@qt.io>

1 files changed, 5 insertions, 1 deletions

diff --git a/src/sql/kernel/qsqlresult.h b/src/sql/kernel/qsqlresult.h
index c16564a516..1135caf765 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;