QStyleSheetStyle: Fix crash that occurs with several instance of QStyleSheetStyle

The problem is that when a widget is destroyed, it was not properly removed
from the cache.  We connected the destroyed signal to a slot in the
QStyleSheetStyle for the first QStyleSheetStyle that handle a widget.
but if this QStyleSheetStyle is destroyed, that connection is lost.

Solution:  Create a new QStyleSheetStyleCaches that will be responsible
to clean the caches. This objects is not destroyed as long as there is
a QStyleSheetStyle instance, so the connection is not lost.

I took the oportunity to move all the caches to this object.

Reveiwed-by: Gabriel
Task-number: QTBUG-11658

1 files changed, 16 insertions, 4 deletions

diff --git a/src/gui/styles/qstylesheetstyle_p.h b/src/gui/styles/qstylesheetstyle_p.h
index fd81437b7a..45649507b7 100644
--- a/src/gui/styles/qstylesheetstyle_p.h
+++ b/src/gui/styles/qstylesheetstyle_p.h
@@ -145,10 +145,6 @@ protected Q_SLOTS:
 protected:
     bool event(QEvent *e);
 
-private Q_SLOTS:
-    void widgetDestroyed(QObject *);
-    void styleDestroyed(QObject *);
-
 private:
     int refcount;
 
@@ -186,6 +182,22 @@ private:
     Q_DECLARE_PRIVATE(QStyleSheetStyle)
 };
 
+class QStyleSheetStyleCaches : public QObject
+{
+    Q_OBJECT
+public Q_SLOTS:
+    void widgetDestroyed(QObject *);
+    void styleDestroyed(QObject *);
+public:
+    QHash<const QWidget *, QVector<QCss::StyleRule> > styleRulesCache;
+    QHash<const QWidget *, QHash<int, bool> > hasStyleRuleCache;
+    typedef QHash<int, QHash<quint64, QRenderRule> > QRenderRules;
+    QHash<const QWidget *, QRenderRules> renderRulesCache;
+    QHash<const QWidget *, QPalette> customPaletteWidgets; // widgets whose palette we tampered
+    QHash<const void *, QCss::StyleSheet> styleSheetCache; // parsed style sheets
+    QSet<const QWidget *> autoFillDisabledWidgets;
+};
+
 
 QT_END_NAMESPACE
 #endif // QT_NO_STYLE_STYLESHEET