Initialize the QSqlQuery to be invalid when creating a sql model

When QSqlQueryModel or QSqlTableModel is created it will create a
QSqlQuery which defaults to using the default QSqlDatabase connection.

If this connection belongs to another thread then it will throw a
warning as this is not safe to use. Since the QSqlQuery is always
recreated when a query is set, the instance which is a member of
the class can effectively be invalid until a new one is set.

Task-number: QTBUG-69213
Change-Id: I68a5dd59fe62788f531d59a0680da11b118ee383
Reviewed-by: Christian Ehrlicher <ch.ehrlicher@gmx.de>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

2 files changed, 2 insertions, 2 deletions

diff --git a/src/sql/models/qsqlquerymodel_p.h b/src/sql/models/qsqlquerymodel_p.h
index 76aaf00c88..d5ca2f89cb 100644
--- a/src/sql/models/qsqlquerymodel_p.h
+++ b/src/sql/models/qsqlquerymodel_p.h
@@ -75,7 +75,7 @@ public:
     void initColOffsets(int size);
     int columnInQuery(int modelColumn) const;
 
-    mutable QSqlQuery query;
+    mutable QSqlQuery query = { QSqlQuery(0) };
     mutable QSqlError error;
     QModelIndex bottom;
     QSqlRecord rec;
diff --git a/src/sql/models/qsqltablemodel_p.h b/src/sql/models/qsqltablemodel_p.h
index faa1b30803..bb568ab444 100644
--- a/src/sql/models/qsqltablemodel_p.h
+++ b/src/sql/models/qsqltablemodel_p.h
@@ -93,7 +93,7 @@ public:
     QSqlTableModel::EditStrategy strategy;
     bool busyInsertingRows;
 
-    QSqlQuery editQuery;
+    QSqlQuery editQuery = { QSqlQuery(0) };
     QSqlIndex primaryIndex;
     QString tableName;
     QString filter;