Fixed crash when adding items with spans

This only occurred if the item added was the only item in the last
row/column, since then the the internal grid failed to expand
(in this case it would always call expand(0, 0), which would not
create the extra row/column).

[ChangeLog][QtWidgets][QGridLayout] Fixed crash that sometimes happened
when adding items with spans that spanned to the bottom/right edge.

Task-number: QTBUG-38052
Change-Id: Iba95f6d9d9356b4d1c84c7b93f4af9b4ea0cf714
Reviewed-by: Paul Olav Tvete <paul.tvete@theqtcompany.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/tests/auto/widgets/kernel/qgridlayout/tst_qgridlayout.cpp b/tests/auto/widgets/kernel/qgridlayout/tst_qgridlayout.cpp
index 004b3b1731..046d6e032f 100644
--- a/tests/auto/widgets/kernel/qgridlayout/tst_qgridlayout.cpp
+++ b/tests/auto/widgets/kernel/qgridlayout/tst_qgridlayout.cpp
@@ -96,6 +96,7 @@ private slots:
     void taskQTBUG_40609_addingWidgetToItsOwnLayout();
     void taskQTBUG_40609_addingLayoutToItself();
     void replaceWidget();
+    void dontCrashWhenExtendsToEnd();
 
 private:
     QWidget *testWidget;
@@ -1728,5 +1729,22 @@ void tst_QGridLayout::replaceWidget()
     }
 }
 
+void tst_QGridLayout::dontCrashWhenExtendsToEnd()
+{
+    QWidget window;
+    window.resize(320,200);
+    QWidget parent(&window);
+    QLabel *lbl0 = new QLabel(QLatin1String("lbl0:"));
+    QLabel *lbl1 = new QLabel(QLatin1String("lbl1:"));
+    QPushButton *pb = new QPushButton(QLatin1String("pb1"));
+    QGridLayout *l = new QGridLayout(&parent);
+    l->addWidget(lbl0, 0, 0);
+    l->addWidget(lbl1, 1, 0);
+    // adding an item in the bottom right corner than spans to the end (!)...
+    l->addWidget(pb, 1, 1, -1, -1);
+    // ...should not cause a crash when the items are distributed....
+    l->setGeometry(QRect(0, 0, 200, 50));    // DONT CRASH HERE
+}
+
 QTEST_MAIN(tst_QGridLayout)
 #include "tst_qgridlayout.moc"