Avoid illegal downcasts in texture and shader handling

Fixes bad type-cast during destruction when objects no longer has the
full type they used to.

Detected by UBSAN.

Change-Id: I4867091901d70d5a882656834eb97a704def1751
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

5 files changed, 12 insertions, 12 deletions

diff --git a/src/quick/items/qquickopenglshadereffect.cpp b/src/quick/items/qquickopenglshadereffect.cpp
index 3aa00340b2..76cb3ace5c 100644
--- a/src/quick/items/qquickopenglshadereffect.cpp
+++ b/src/quick/items/qquickopenglshadereffect.cpp
@@ -221,7 +221,7 @@ QQuickOpenGLShaderEffectCommon::~QQuickOpenGLShaderEffectCommon()
         clearSignalMappers(shaderType);
 }
 
-void QQuickOpenGLShaderEffectCommon::disconnectPropertySignals(QQuickItem *item, Key::ShaderType shaderType)
+void QQuickOpenGLShaderEffectCommon::disconnectPropertySignals(QObject *obj, Key::ShaderType shaderType)
 {
     for (int i = 0; i < uniformData[shaderType].size(); ++i) {
         if (signalMappers[shaderType].at(i) == 0)
@@ -229,12 +229,11 @@ void QQuickOpenGLShaderEffectCommon::disconnectPropertySignals(QQuickItem *item,
         const UniformData &d = uniformData[shaderType].at(i);
         auto mapper = signalMappers[shaderType].at(i);
         void *a = mapper;
-        QObjectPrivate::disconnect(item, mapper->signalIndex(), &a);
+        QObjectPrivate::disconnect(obj, mapper->signalIndex(), &a);
         if (d.specialType == UniformData::Sampler || d.specialType == UniformData::SamplerExternal) {
             QQuickItem *source = qobject_cast<QQuickItem *>(qvariant_cast<QObject *>(d.value));
             if (source) {
-                if (item->window())
-                    QQuickItemPrivate::get(source)->derefWindow();
+                QQuickItemPrivate::get(source)->derefWindow();
                 QObject::disconnect(source, SIGNAL(destroyed(QObject*)), host, SLOT(sourceDestroyed(QObject*)));
             }
         }
diff --git a/src/quick/items/qquickopenglshadereffect_p.h b/src/quick/items/qquickopenglshadereffect_p.h
index 0c2adadc62..3087c1eb0b 100644
--- a/src/quick/items/qquickopenglshadereffect_p.h
+++ b/src/quick/items/qquickopenglshadereffect_p.h
@@ -89,7 +89,7 @@ struct Q_QUICK_PRIVATE_EXPORT QQuickOpenGLShaderEffectCommon
 
     ~QQuickOpenGLShaderEffectCommon();
 
-    void disconnectPropertySignals(QQuickItem *item, Key::ShaderType shaderType);
+    void disconnectPropertySignals(QObject *item, Key::ShaderType shaderType);
     void connectPropertySignals(QQuickItem *item, const QMetaObject *itemMetaObject, Key::ShaderType shaderType);
     void updateParseLog(bool ignoreAttributes);
     void lookThroughShaderCode(QQuickItem *item, const QMetaObject *itemMetaObject, Key::ShaderType shaderType, const QByteArray &code);
diff --git a/src/quick/items/qquickopenglshadereffectnode.cpp b/src/quick/items/qquickopenglshadereffectnode.cpp
index f32b32491b..f96ebebcd6 100644
--- a/src/quick/items/qquickopenglshadereffectnode.cpp
+++ b/src/quick/items/qquickopenglshadereffectnode.cpp
@@ -477,11 +477,11 @@ void QQuickOpenGLShaderEffectMaterial::updateTextures() const
     }
 }
 
-void QQuickOpenGLShaderEffectMaterial::invalidateTextureProvider(QSGTextureProvider *provider)
+void QQuickOpenGLShaderEffectMaterial::invalidateTextureProvider(const QObject *provider)
 {
     for (int i = 0; i < textureProviders.size(); ++i) {
         if (provider == textureProviders.at(i))
-            textureProviders[i] = 0;
+            textureProviders[i] = nullptr;
     }
 }
 
@@ -505,10 +505,10 @@ void QQuickOpenGLShaderEffectNode::markDirtyTexture()
     Q_EMIT dirtyTexture();
 }
 
-void QQuickOpenGLShaderEffectNode::textureProviderDestroyed(QObject *object)
+void QQuickOpenGLShaderEffectNode::textureProviderDestroyed(const QObject *object)
 {
     Q_ASSERT(material());
-    static_cast<QQuickOpenGLShaderEffectMaterial *>(material())->invalidateTextureProvider(static_cast<QSGTextureProvider *>(object));
+    static_cast<QQuickOpenGLShaderEffectMaterial *>(material())->invalidateTextureProvider(object);
 }
 
 void QQuickOpenGLShaderEffectNode::preprocess()
diff --git a/src/quick/items/qquickopenglshadereffectnode_p.h b/src/quick/items/qquickopenglshadereffectnode_p.h
index 7c75bb3126..6d68ba87b9 100644
--- a/src/quick/items/qquickopenglshadereffectnode_p.h
+++ b/src/quick/items/qquickopenglshadereffectnode_p.h
@@ -122,7 +122,7 @@ public:
 
     void setProgramSource(const QQuickOpenGLShaderEffectMaterialKey &source);
     void updateTextures() const;
-    void invalidateTextureProvider(QSGTextureProvider *provider);
+    void invalidateTextureProvider(const QObject *provider);
 
     static void cleanupMaterialCache();
 
@@ -159,7 +159,7 @@ Q_SIGNALS:
 
 private Q_SLOTS:
     void markDirtyTexture();
-    void textureProviderDestroyed(QObject *object);
+    void textureProviderDestroyed(const QObject *object);
 };
 
 QT_END_NAMESPACE
diff --git a/src/quick/items/qquickshadereffect.cpp b/src/quick/items/qquickshadereffect.cpp
index ab79b69c8c..05d9e5e36d 100644
--- a/src/quick/items/qquickshadereffect.cpp
+++ b/src/quick/items/qquickshadereffect.cpp
@@ -795,7 +795,8 @@ bool QQuickShaderEffect::event(QEvent *e)
         return QQuickItem::event(e);
     }
 #endif
-    m_impl->handleEvent(e);
+    if (m_impl)
+        m_impl->handleEvent(e);
     return QQuickItem::event(e);
 }