Fix crash on application exit

The destruction order of global statics is undefined. If the factory
map got destroyed before the map deleter, we would not only leak memory,
but also access a deleted object, which is undefined behaviour and
did lead to crashes for me.

Change-Id: I27c664751b1acdaa08cf35989e09db3e06c6b3c1
Reviewed-by: Pasi Keränen <pasi.keranen@qt.io>

1 files changed, 13 insertions, 8 deletions

diff --git a/src/imports/qtcanvas3d/teximage3d.cpp b/src/imports/qtcanvas3d/teximage3d.cpp
index d3e1e07..9814e6b 100644
--- a/src/imports/qtcanvas3d/teximage3d.cpp
+++ b/src/imports/qtcanvas3d/teximage3d.cpp
@@ -47,18 +47,23 @@ QT_BEGIN_NAMESPACE
 
 QT_CANVAS3D_BEGIN_NAMESPACE
 
-static QMap<QQmlEngine *,CanvasTextureImageFactory *>m_qmlEngineToImageFactoryMap;
-static ulong m_texId = 0;
-
-class StaticFactoryMapDeleter
+class EngineToImageFactoryMap : public QMap<QQmlEngine *, CanvasTextureImageFactory *>
 {
+    bool isDeleting = false;
 public:
-    StaticFactoryMapDeleter() {}
-    ~StaticFactoryMapDeleter() {
-        qDeleteAll(m_qmlEngineToImageFactoryMap);
+    ~EngineToImageFactoryMap() {
+        isDeleting = true;
+        qDeleteAll(*this);
+    }
+    void remove(QQmlEngine *e) {
+        if (isDeleting)
+            return;
+        QMap<QQmlEngine *, CanvasTextureImageFactory *>::remove(e);
     }
 };
-static StaticFactoryMapDeleter staticFactoryMapDeleter;
+
+static EngineToImageFactoryMap m_qmlEngineToImageFactoryMap;
+static ulong m_texId = 0;
 
 CanvasTextureImageFactory::CanvasTextureImageFactory(QQmlEngine *engine, QObject *parent) :
     QObject(parent)