From 3ab6653d97a5dd01fd5f5cb4e52d5816274e4cbd Mon Sep 17 00:00:00 2001
From: Jan Arve Saether <jan-arve.saether@theqtcompany.com>
Date: Fri, 6 Feb 2015 14:47:16 +0100
Subject: [PATCH] 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>
---
 src/widgets/kernel/qgridlayout.cpp             |  2 +-
 .../kernel/qgridlayout/tst_qgridlayout.cpp     | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/widgets/kernel/qgridlayout.cpp b/src/widgets/kernel/qgridlayout.cpp
index 10d338c40c..3de0eb7960 100644
--- a/src/widgets/kernel/qgridlayout.cpp
+++ b/src/widgets/kernel/qgridlayout.cpp
@@ -565,7 +565,7 @@ void QGridLayoutPrivate::add(QGridBox *box, int row1, int row2, int col1, int co
         add(box, row1, col1);
         return;
     }
-    expand(row2 + 1, col2 + 1);
+    expand(qMax(row1, row2) + 1, qMax(col1, col2) + 1);
     box->row = row1;
     box->col = col1;
 
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"