Reset palette resolve mask in windows vista style

The palette set by windows vista style during polish doesn't allow style-
sheet style to override it.

This patch reset resolve mask for the palette set by windows vista style
and thus it can be overridden.

Fixes: QTBUG-115511
Change-Id: Ifcaf441f806cfa0273599b3dce83fdfaec3f5a66
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
(cherry picked from commit 4cf92d83c3a8966fd1716939829fdbd4642810e9)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/plugins/styles/windowsvista/qwindowsvistastyle.cpp

@@ -4669,6 +4669,7 @@ void QWindowsVistaStyle::polish(QWidget *widget)
             QPalette pal = widget->palette();
             pal.setColor(QPalette::ButtonText, QColor(21, 28, 85));
             pal.setColor(QPalette::BrightText, QColor(7, 64, 229));
+            pal.setResolveMask(0);
             widget->setPalette(pal);
         }
 #endif // QT_CONFIG(commandlinkbutton)
@@ -4682,6 +4683,7 @@ void QWindowsVistaStyle::polish(QWidget *widget)
                 QColor textColor = QColor::fromRgb(bgRef);
                 QPalette pal;
                 pal.setColor(QPalette::All, QPalette::ToolTipText, textColor);
+                pal.setResolveMask(0);
                 widget->setPalette(pal);
             }
         } else if (qobject_cast<QMessageBox *> (widget)) {

src/widgets/kernel/qapplication.cpp

@@ -496,8 +496,11 @@ void QApplicationPrivate::init()
 void qt_init_tooltip_palette()
 {
 #if QT_CONFIG(tooltip)
-    if (const QPalette *toolTipPalette = QGuiApplicationPrivate::platformTheme()->palette(QPlatformTheme::ToolTipPalette))
-        QToolTip::setPalette(*toolTipPalette);
+    if (const QPalette *toolTipPalette = QGuiApplicationPrivate::platformTheme()->palette(QPlatformTheme::ToolTipPalette)) {
+        QPalette toolTipPal = *toolTipPalette;
+        toolTipPal.setResolveMask(0);
+        QToolTip::setPalette(toolTipPal);
+    }
 #endif
 }
 

tests/auto/widgets/styles/qstylesheetstyle/tst_qstylesheetstyle.cpp

@@ -38,7 +38,7 @@
 #include <private/qstylesheetstyle_p.h>
 #include <private/qhighdpiscaling_p.h>
 #include <QtTest/private/qtesthelpers_p.h>
-
+#include <qpa/qplatformtheme.h>
 #include <QtWidgets/private/qapplication_p.h>
 
 using namespace QTestPrivate;
@@ -94,6 +94,7 @@ private slots:
     void proxyStyle();
     void dialogButtonBox();
     void emptyStyleSheet();
+    void toolTip_data();
     void toolTip();
     void embeddedFonts();
     void opaquePaintEvent_data();
@@ -1658,19 +1659,32 @@ private:
     const QString m_oldStyleName;
 };
 
+void tst_QStyleSheetStyle::toolTip_data()
+{
+    QTest::addColumn<QString>("style");
+
+    QTest::newRow("fusion") << QString("Fusion");
+#ifdef Q_OS_WINDOWS
+    QTest::newRow("windowsvista") << QString("WindowsVista");
+#endif
+}
+
 void tst_QStyleSheetStyle::toolTip()
 {
+    QFETCH(QString, style);
+
     if (QGuiApplication::platformName().startsWith(QLatin1String("wayland"), Qt::CaseInsensitive))
         QSKIP("Wayland: This fails. Figure out why.");
 
-    qApp->setStyleSheet(QString());
     QWidget w;
     w.resize(m_testSize);
     w.setWindowTitle(QTest::currentTestFunction());
+
     // Use "Fusion" to prevent the Vista style from clobbering the tooltip palette in polish().
-    QStyle *fusionStyle = QStyleFactory::create(QLatin1String("Fusion"));
-    QVERIFY(fusionStyle);
-    ApplicationStyleSetter as(fusionStyle);
+    QStyle *appStyle = QStyleFactory::create(style);
+    QVERIFY(appStyle);
+    ApplicationStyleSetter as(appStyle);
+
     QHBoxLayout layout(&w);
     w.setLayout(&layout);
 
@@ -1698,23 +1712,41 @@ void tst_QStyleSheetStyle::toolTip()
     wid4->setToolTip("this is wid4");
     wid4->setObjectName("wid4");
 
+    QWidget *wid5 = new QPushButton("wid5", &w);
+    layout.addWidget(wid5);
+    wid5->setStyleSheet("QToolTip { background: #ff0; color: #f00 }");
+    wid5->setToolTip("this is wid5");
+    wid5->setObjectName("wid5");
+
     centerOnScreen(&w);
     w.show();
     QApplicationPrivate::setActiveWindow(&w);
     QVERIFY(QTest::qWaitForWindowActive(&w));
 
-    const QColor normalToolTip = QToolTip::palette().color(QPalette::Inactive, QPalette::ToolTipBase);
+    QColor normalToolTipBgColor = QToolTip::palette().color(QPalette::Inactive, QPalette::ToolTipBase);
+
+#ifdef Q_OS_MACOS
+    // macOS uses tool tip text color set in label palette
+    const QPalette *labelPalette = QGuiApplicationPrivate::platformTheme()->palette(QPlatformTheme::LabelPalette);
+    QColor normalToolTipFgColor = labelPalette->color(QPalette::Inactive, QPalette::ToolTipText);
+#else
+    QColor normalToolTipFgColor = QToolTip::palette().color(QPalette::Inactive, QPalette::ToolTipText);
+#endif
+
     // Tooltip on the widget without stylesheet, then to other widget,
     // including one without stylesheet (the tooltip will be reused,
     // but its color must change)
-    const QWidgetList widgets{wid4, wid1, wid2, wid3, wid4};
-    const QList<QColor> colors { normalToolTip, QColor("#ae2"), QColor("#f81"), QColor("#0b8"),
-                                 normalToolTip };
+    const QWidgetList widgets{wid4, wid1, wid2, wid3, wid4, wid5};
+    const QList<QColor> bgcolors { normalToolTipBgColor, QColor("#ae2"), QColor("#f81"),
+                                QColor("#0b8"), normalToolTipBgColor, QColor("#ff0")};
+    const QList<QColor> fgcolors { normalToolTipFgColor, normalToolTipFgColor, normalToolTipFgColor,
+                                normalToolTipFgColor, normalToolTipFgColor, QColor("#f00")};
 
     QWidgetList topLevels;
     for (int i = 0; i < widgets.size() ; ++i) {
         QWidget *wid = widgets.at(i);
-        QColor col = colors.at(i);
+        QColor bgColor = bgcolors.at(i);
+        QColor fgColor = fgcolors.at(i);
 
         QToolTip::showText( QPoint(0,0) , "This is " + wid->objectName(), wid);
 
@@ -1726,9 +1758,20 @@ void tst_QStyleSheetStyle::toolTip()
                 break;
             }
         }
+
         QVERIFY(tooltip);
         QTRY_VERIFY(tooltip->isVisible()); // Wait until Roll-Effect is finished (Windows Vista)
-        QCOMPARE(tooltip->palette().color(tooltip->backgroundRole()), col);
+
+#ifdef Q_OS_WINDOWS
+        // If tooltip palette contains empty resolve mask, validate with inherited palette
+        if (!tooltip->palette().resolveMask()) {
+            bgColor = w.palette().color(tooltip->backgroundRole());
+            fgColor = w.palette().color(tooltip->foregroundRole());
+        }
+#endif
+
+        QCOMPARE(tooltip->palette().color(tooltip->backgroundRole()), bgColor);
+        QCOMPARE(tooltip->palette().color(tooltip->foregroundRole()), fgColor);
     }
 
     QToolTip::showText( QPoint(0,0) , "This is " + wid3->objectName(), wid3);