QBoxLayout::setGeometry would not respect the widget min/max width

When calling heightforWidth after a geometry change, the width actually used
could be outside the widget's width bounds. The height could then be smaller
than needed to fit the widget's contents resulting in a clipped widget being
drawn. Auto-test included.

Reviewed-by: Olivier
Task-number: QTBUG-7103

2 files changed, 31 insertions, 2 deletions

diff --git a/src/gui/kernel/qboxlayout.cpp b/src/gui/kernel/qboxlayout.cpp
index d965933..fd16861 100644
--- a/src/gui/kernel/qboxlayout.cpp
+++ b/src/gui/kernel/qboxlayout.cpp
@@ -830,9 +830,11 @@ void QBoxLayout::setGeometry(const QRect &r)
         if (d->hasHfw && !horz(d->dir)) {
             for (int i = 0; i < n; i++) {
                 QBoxLayoutItem *box = d->list.at(i);
-                if (box->item->hasHeightForWidth())
+                if (box->item->hasHeightForWidth()) {
+                    int width = qBound(box->item->minimumSize().width(), s.width(), box->item->maximumSize().width());
                     a[i].sizeHint = a[i].minimumSize =
-                                    box->item->heightForWidth(s.width());
+                                    box->item->heightForWidth(width);
+                }
             }
         }
 
diff --git a/tests/auto/qboxlayout/tst_qboxlayout.cpp b/tests/auto/qboxlayout/tst_qboxlayout.cpp
index 8887288..48235e8 100644
--- a/tests/auto/qboxlayout/tst_qboxlayout.cpp
+++ b/tests/auto/qboxlayout/tst_qboxlayout.cpp
@@ -66,6 +66,8 @@ private slots:
     void sizeConstraints();
     void setGeometry();
     void setStyleShouldChangeSpacing();
+
+    void taskQTBUG_7103_minMaxWidthNotRespected();
 };
 
 class CustomLayoutStyle : public QWindowsStyle
@@ -246,6 +248,31 @@ void tst_QBoxLayout::setStyleShouldChangeSpacing()
     delete style2;
 }
 
+void tst_QBoxLayout::taskQTBUG_7103_minMaxWidthNotRespected()
+{
+    QLabel *label = new QLabel("Qt uses standard C++, but makes extensive use of the C pre-processor to enrich the language. Qt can also be used in several other programming languages via language bindings. It runs on all major platforms, and has extensive internationalization support. Non-GUI features include SQL database access, XML parsing, thread management, network support and a unified cross-platform API for file handling.");
+    label->setWordWrap(true);
+    label->setFixedWidth(200);
+
+    QVBoxLayout *layout = new QVBoxLayout;
+    layout->addWidget(label);
+    layout->addSpacerItem(new QSpacerItem(1, 1, QSizePolicy::Fixed, QSizePolicy::Expanding));
+
+    QWidget widget;
+    widget.setLayout(layout);
+    widget.show();
+    QTest::qWaitForWindowShown(&widget);
+
+    int height = label->height();
+
+    QRect g = widget.geometry();
+    g.setWidth(600);
+    widget.setGeometry(g);
+
+    QTest::qWait(50);
+
+    QCOMPARE(label->height(), height);
+}
 
 QTEST_MAIN(tst_QBoxLayout)
 #include "tst_qboxlayout.moc"