Fix crash on destroying web entities and overlays

interface/src/ui/overlays/Web3DOverlay.cpp

@@ -73,7 +73,12 @@ void Web3DOverlay::render(RenderArgs* args) {
     QOpenGLContext * currentContext = QOpenGLContext::currentContext();
     QSurface * currentSurface = currentContext->surface();
     if (!_webSurface) {
-        _webSurface = new OffscreenQmlSurface();
+        auto deleter = [](OffscreenQmlSurface* webSurface) {
+            AbstractViewStateInterface::instance()->postLambdaEvent([webSurface] {
+                webSurface->deleteLater();
+            });
+        };
+        _webSurface = QSharedPointer<OffscreenQmlSurface>(new OffscreenQmlSurface(), deleter);
         _webSurface->create(currentContext);
         _webSurface->setBaseUrl(QUrl::fromLocalFile(PathUtils::resourcesPath() + "/qml/controls/"));
         _webSurface->load("WebView.qml");
@@ -95,8 +100,9 @@ void Web3DOverlay::render(RenderArgs* args) {
     }
 
     if (!_texture) {
-        _texture = gpu::TexturePointer(gpu::Texture::createExternal2D([this](uint32_t recycleTexture, void* recycleFence) {
+        auto webSurface = _webSurface;
-            _webSurface->releaseTexture({ recycleTexture, recycleFence });
+        _texture = gpu::TexturePointer(gpu::Texture::createExternal2D([webSurface](uint32_t recycleTexture, void* recycleFence) {
+            webSurface->releaseTexture({ recycleTexture, recycleFence });
         }));
         _texture->setSource(__FUNCTION__);
     }

interface/src/ui/overlays/Web3DOverlay.h

@@ -41,7 +41,7 @@ public:
     virtual Web3DOverlay* createClone() const override;
 
 private:
-    OffscreenQmlSurface* _webSurface{ nullptr };
+    QSharedPointer<OffscreenQmlSurface> _webSurface;
     QMetaObject::Connection _connection;
     gpu::TexturePointer _texture;
     QString _url;

libraries/entities-renderer/src/RenderableWebEntityItem.cpp

@@ -129,7 +129,19 @@ bool RenderableWebEntityItem::buildWebSurface(EntityTreeRenderer* renderer) {
     // Save the original GL context, because creating a QML surface will create a new context
     QOpenGLContext * currentContext = QOpenGLContext::currentContext();
     QSurface * currentSurface = currentContext->surface();
-    _webSurface = new OffscreenQmlSurface();
+
+    auto deleter = [](OffscreenQmlSurface* webSurface) {
+        AbstractViewStateInterface::instance()->postLambdaEvent([webSurface] {
+            webSurface->deleteLater();
+        });
+    };
+    _webSurface = QSharedPointer<OffscreenQmlSurface>(new OffscreenQmlSurface(), deleter);
+
+    // The lifetime of the QML surface MUST be managed by the main thread
+    // Additionally, we MUST use local variables copied by value, rather than
+    // member variables, since they would implicitly refer to a this that 
+    // is no longer valid
+
     _webSurface->create(currentContext);
     _webSurface->setBaseUrl(QUrl::fromLocalFile(PathUtils::resourcesPath() + "/qml/controls/"));
     _webSurface->load("WebView.qml", [&](QQmlContext* context, QObject* obj) {
@@ -215,9 +227,11 @@ void RenderableWebEntityItem::render(RenderArgs* args) {
     _webSurface->resize(QSize(windowSize.x, windowSize.y));
 
     if (!_texture) {
-        _texture = gpu::TexturePointer(gpu::Texture::createExternal2D([this](uint32_t recycleTexture, void* recycleFence) {
+        auto webSurface = _webSurface;
-            _webSurface->releaseTexture({ recycleTexture, recycleFence });
+        auto recycler = [webSurface] (uint32_t recycleTexture, void* recycleFence) {
-        }));
+            webSurface->releaseTexture({ recycleTexture, recycleFence });
+        };
+        _texture = gpu::TexturePointer(gpu::Texture::createExternal2D(recycler));
         _texture->setSource(__FUNCTION__);
     }
     OffscreenQmlSurface::TextureAndFence newTextureAndFence;
@@ -352,16 +366,7 @@ void RenderableWebEntityItem::destroyWebSurface() {
         _mouseMoveConnection = QMetaObject::Connection();
         QObject::disconnect(_hoverLeaveConnection);
         _hoverLeaveConnection = QMetaObject::Connection();
-
+        _webSurface.reset();
-        // The lifetime of the QML surface MUST be managed by the main thread
-        // Additionally, we MUST use local variables copied by value, rather than
-        // member variables, since they would implicitly refer to a this that
-        // is no longer valid
-        auto webSurface = _webSurface;
-        AbstractViewStateInterface::instance()->postLambdaEvent([webSurface] {
-            webSurface->deleteLater();
-        });
-        _webSurface = nullptr;
     }
 }
 

libraries/entities-renderer/src/RenderableWebEntityItem.h

@@ -78,7 +78,7 @@ private:
     void destroyWebSurface();
     glm::vec2 getWindowSize() const;
 
-    OffscreenQmlSurface* _webSurface{ nullptr };
+    QSharedPointer<OffscreenQmlSurface> _webSurface;
     QMetaObject::Connection _connection;
     gpu::TexturePointer _texture;
     ivec2  _lastPress { INT_MIN };

libraries/gpu-gl/src/gpu/gl/GLTexture.cpp

@@ -182,8 +182,11 @@ GLTexture::~GLTexture() {
     if (backend) {
         if (_external) {
             auto recycler = _gpuObject.getExternalRecycler();
-            assert(recycler);
+            if (recycler) {
-            backend->releaseExternalTexture(_id, recycler);
+                backend->releaseExternalTexture(_id, recycler);
+            } else {
+                qWarning() << "No recycler available for texture " << _id << " possible leak";
+            }
         } else if (_id) {
             backend->releaseTexture(_id, _size);
         }