Fix crash in QDeclarativePixmapStore global static dtor

Due to the undefined ordering of global static dtors, the QDPS dtor
could run after the texture factories were deleted.  Thus, the QDPS
dtor cannot call the cost() method of the pixmap data during its
destructor, as this could cause a crash.

Change-Id: I5d23066dc57e1992cf9d1c13d514f06c431bc752
Reviewed-by: Alan Alpert <alan.alpert@nokia.com>

2 files changed, 7 insertions, 5 deletions

diff --git a/src/declarative/qml/qdeclarativeimageprovider.h b/src/declarative/qml/qdeclarativeimageprovider.h
index 55a5ca2d23..16af45282c 100644
--- a/src/declarative/qml/qdeclarativeimageprovider.h
+++ b/src/declarative/qml/qdeclarativeimageprovider.h
@@ -58,7 +58,7 @@ class Q_DECLARATIVE_EXPORT QDeclarativeTextureFactory : public QObject
 {
 public:
     QDeclarativeTextureFactory();
-    ~QDeclarativeTextureFactory();
+    virtual ~QDeclarativeTextureFactory();
 
     virtual QSGTexture *createTexture(QQuickCanvas *canvas) const = 0;
     virtual QSize textureSize() const = 0;
diff --git a/src/quick/util/qdeclarativepixmapcache.cpp b/src/quick/util/qdeclarativepixmapcache.cpp
index 95cbd361b8..1f187a7f03 100644
--- a/src/quick/util/qdeclarativepixmapcache.cpp
+++ b/src/quick/util/qdeclarativepixmapcache.cpp
@@ -762,6 +762,8 @@ void QDeclarativePixmapStore::unreferencePixmap(QDeclarativePixmapData *data)
 
     data->nextUnreferenced = m_unreferencedPixmaps;
     data->prevUnreferencedPtr = &m_unreferencedPixmaps;
+    if (!m_destroying) // the texture factories may have been cleaned up already.
+        m_unreferencedCost += data->cost();
 
     m_unreferencedPixmaps = data;
     if (m_unreferencedPixmaps->nextUnreferenced) {
@@ -772,8 +774,6 @@ void QDeclarativePixmapStore::unreferencePixmap(QDeclarativePixmapData *data)
     if (!m_lastUnreferencedPixmap)
         m_lastUnreferencedPixmap = data;
 
-    m_unreferencedCost += data->cost();
-
     shrinkCache(-1); // Shrink the cache incase it has become larger than cache_limit
 
     if (m_timerId == -1 && m_unreferencedPixmaps && !m_destroying)
@@ -810,8 +810,10 @@ void QDeclarativePixmapStore::shrinkCache(int remove)
         data->prevUnreferencedPtr = 0;
         data->prevUnreferenced = 0;
 
-        remove -= data->cost();
-        m_unreferencedCost -= data->cost();
+        if (!m_destroying) {
+            remove -= data->cost();
+            m_unreferencedCost -= data->cost();
+        }
         data->removeFromCache();
         delete data;
     }