Fixed: Setting a border using stylesheet for QComboBox adds an unwated frame.

This was already fix. But there was still a frame if there was a
stylesheet on the applicaiton.

The reason is that the frame's constructor call the style for some
hints. And later the combobox will query the style again for the frame
hint, before the view get polished.
The problem is that the StyleSheetStyle will fill the css cache with
wrong information on the first call.

This is not visible if there is no stylesheet as in the constructor, the
widget style is still the default application stylesheet if there is no
global applicaiton stylesheet.

Task-number: 254589
Reviewed-by: jbache
BT:
(cherry picked from commit d0bc0a26f8ac4c2f02819c262b8aa7c3dd1cad3b)

2 files changed, 11 insertions, 6 deletions

diff --git a/src/gui/styles/qstylesheetstyle.cpp b/src/gui/styles/qstylesheetstyle.cpp
index 8ec0f8f..865f0fd 100644
--- a/src/gui/styles/qstylesheetstyle.cpp
+++ b/src/gui/styles/qstylesheetstyle.cpp
@@ -5252,9 +5252,12 @@ int QStyleSheetStyle::styleHint(StyleHint sh, const QStyleOption *opt, const QWi
 #ifndef QT_NO_COMBOBOX
             if (qobject_cast<const QComboBox *>(w)) {
                 QAbstractItemView *view = qFindChild<QAbstractItemView *>(w);
-                QRenderRule subRule = renderRule(view, PseudoElement_None);
-                if (subRule.hasBox() || !subRule.hasNativeBorder())
-                    return QFrame::NoFrame;
+                if (view) {
+                    view->ensurePolished();
+                    QRenderRule subRule = renderRule(view, PseudoElement_None);
+                    if (subRule.hasBox() || !subRule.hasNativeBorder())
+                        return QFrame::NoFrame;
+                }
             }
 #endif // QT_NO_COMBOBOX
             break;
diff --git a/tests/auto/qcombobox/tst_qcombobox.cpp b/tests/auto/qcombobox/tst_qcombobox.cpp
index 95bd490..8ee6e13 100644
--- a/tests/auto/qcombobox/tst_qcombobox.cpp
+++ b/tests/auto/qcombobox/tst_qcombobox.cpp
@@ -2171,7 +2171,7 @@ void tst_QComboBox::noScrollbar_data()
     QTest::newRow("everything and more") << QString::fromLatin1("QAbstractItemView {  border: 1px 3px 5px 1px solid blue; "
                                                        " padding: 2px 5px 3px 1px; margin: 2px 5px 3px 1px;  } "
                                                        " QAbstractItemView::item {  border: 2px solid green; "
-                                                       "                      padding: 1px 1px 2px 2px margin: 1px; } " );
+                                                       "                      padding: 1px 1px 2px 2px; margin: 1px; } " );
 }
 
 void tst_QComboBox::noScrollbar()
@@ -2179,10 +2179,11 @@ void tst_QComboBox::noScrollbar()
     QStringList initialContent;
     initialContent << "foo" << "bar" << "foobar" << "moo";
     QFETCH(QString, stylesheet);
+    QString oldCss = qApp->styleSheet();
+    qApp->setStyleSheet(stylesheet);
 
     {
         QComboBox comboBox;
-        comboBox.setStyleSheet(stylesheet);
         comboBox.addItems(initialContent);
         comboBox.show();
         comboBox.resize(200, comboBox.height());
@@ -2196,7 +2197,6 @@ void tst_QComboBox::noScrollbar()
     {
         QTableWidget *table = new QTableWidget(2,2);
         QComboBox comboBox;
-        comboBox.setStyleSheet(stylesheet);
         comboBox.setView(table);
         comboBox.setModel(table->model());
         comboBox.show();
@@ -2207,6 +2207,8 @@ void tst_QComboBox::noScrollbar()
         QVERIFY(!comboBox.view()->horizontalScrollBar()->isVisible());
         QVERIFY(!comboBox.view()->verticalScrollBar()->isVisible());
     }
+
+    qApp->setStyleSheet(oldCss);
 }
 
 void tst_QComboBox::setItemDelegate()