Fix potential null pointer dereferencing

These were found by
http://www.viva64.com/en/b/025
most issues are rather cosmetic.

Change-Id: I7cc12610aae6a43d26bedb9b480863c0695ddfa3
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

6 files changed, 17 insertions, 11 deletions

diff --git a/src/particles/qquickitemparticle.cpp b/src/particles/qquickitemparticle.cpp
index 0fe0b2ae0b..1f357df20d 100644
--- a/src/particles/qquickitemparticle.cpp
+++ b/src/particles/qquickitemparticle.cpp
@@ -163,6 +163,7 @@ void QQuickItemParticle::tick(int time)
     m_deletables.clear();
 
     foreach (QQuickParticleData* d, m_loadables){
+        Q_ASSERT(d);
         if (m_stasis.contains(d->delegate))
             qWarning() << "Current model particles prefers overwrite:false";
         //remove old item from the particle that is dying to make room for this one
diff --git a/src/qml/qml/qqmlimport.cpp b/src/qml/qml/qqmlimport.cpp
index 5799886faa..bde61dca9d 100644
--- a/src/qml/qml/qqmlimport.cpp
+++ b/src/qml/qml/qqmlimport.cpp
@@ -1851,17 +1851,21 @@ bool QQmlImportDatabase::registerPluginTypes(QObject *instance, const QString &b
             // This is an 'identified' module
             if (typeNamespace != uri) {
                 // The namespace for type registrations must match the URI for locating the module
-                QQmlError error;
-                error.setDescription(tr("Module namespace '%1' does not match import URI '%2'").arg(typeNamespace).arg(uri));
-                errors->prepend(error);
+                if (errors) {
+                    QQmlError error;
+                    error.setDescription(tr("Module namespace '%1' does not match import URI '%2'").arg(typeNamespace).arg(uri));
+                    errors->prepend(error);
+                }
                 return false;
             }
 
             if (QQmlMetaType::namespaceContainsRegistrations(typeNamespace)) {
                 // Other modules have already installed to this namespace
-                QQmlError error;
-                error.setDescription(tr("Namespace '%1' has already been used for type registration").arg(typeNamespace));
-                errors->prepend(error);
+                if (errors) {
+                    QQmlError error;
+                    error.setDescription(tr("Namespace '%1' has already been used for type registration").arg(typeNamespace));
+                    errors->prepend(error);
+                }
                 return false;
             } else {
                 QQmlMetaType::protectNamespace(typeNamespace);
diff --git a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
index d0d6839bdc..a7db7d214e 100644
--- a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
+++ b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
@@ -980,12 +980,13 @@ ReturnedValue QtObject::method_createQmlObject(CallContext *ctx)
     QQmlEngine *engine = v8engine->engine();
 
     QQmlContextData *context = v8engine->callingContext();
+    Q_ASSERT(context);
     QQmlContext *effectiveContext = 0;
     if (context->isPragmaLibraryContext)
         effectiveContext = engine->rootContext();
     else
         effectiveContext = context->asQQmlContext();
-    Q_ASSERT(context && effectiveContext);
+    Q_ASSERT(effectiveContext);
 
     QString qml = ctx->callData->args[0].toQStringNoThrow();
     if (qml.isEmpty())
@@ -1086,10 +1087,10 @@ ReturnedValue QtObject::method_createComponent(CallContext *ctx)
     QQmlEngine *engine = v8engine->engine();
 
     QQmlContextData *context = v8engine->callingContext();
+    Q_ASSERT(context);
     QQmlContextData *effectiveContext = context;
     if (context->isPragmaLibraryContext)
         effectiveContext = 0;
-    Q_ASSERT(context);
 
     QString arg = ctx->callData->args[0].toQStringNoThrow();
     if (arg.isEmpty())
diff --git a/src/quick/items/qquickmousearea.cpp b/src/quick/items/qquickmousearea.cpp
index baa48291e2..d4b64ea75a 100644
--- a/src/quick/items/qquickmousearea.cpp
+++ b/src/quick/items/qquickmousearea.cpp
@@ -894,7 +894,7 @@ bool QQuickMouseArea::sendMouseEvent(QMouseEvent *event)
         default:
             break;
         }
-        grabber = c->mouseGrabberItem();
+        grabber = c ? c->mouseGrabberItem() : 0;
         if (grabber && stealThisEvent && !grabber->keepMouseGrab() && grabber != this)
             grabMouse();
 
diff --git a/src/quick/items/qquickmultipointtoucharea.cpp b/src/quick/items/qquickmultipointtoucharea.cpp
index c20559454e..ee31c018af 100644
--- a/src/quick/items/qquickmultipointtoucharea.cpp
+++ b/src/quick/items/qquickmultipointtoucharea.cpp
@@ -844,7 +844,7 @@ bool QQuickMultiPointTouchArea::sendMouseEvent(QMouseEvent *event)
         default:
             break;
         }
-        grabber = c->mouseGrabberItem();
+        grabber = c ? c->mouseGrabberItem() : 0;
         if (grabber && stealThisEvent && !grabber->keepMouseGrab() && grabber != this)
             grabMouse();
 
diff --git a/src/quick/util/qquickpixmapcache.cpp b/src/quick/util/qquickpixmapcache.cpp
index a7f9174219..a5a56949e6 100644
--- a/src/quick/util/qquickpixmapcache.cpp
+++ b/src/quick/util/qquickpixmapcache.cpp
@@ -805,7 +805,7 @@ void QQuickPixmapStore::unreferencePixmap(QQuickPixmapData *data)
     if (!m_lastUnreferencedPixmap)
         m_lastUnreferencedPixmap = data;
 
-    shrinkCache(-1); // Shrink the cache incase it has become larger than cache_limit
+    shrinkCache(-1); // Shrink the cache in case it has become larger than cache_limit
 
     if (m_timerId == -1 && m_unreferencedPixmaps && !m_destroying)
         m_timerId = startTimer(CACHE_EXPIRE_TIME * 1000);