Fix regression in orphaned texture clean-up

The recently refactored QWaylandTextureOrphanage
used sender() in a DirectionConnection,
which doesn't work if sender and receiver live in
different threads - which happens if multiple windows
(and therefor multiple QSGRenderThread) exist

This patch fixed that by replacing sender()
with a lambda capture

Also: fix a weirdly phrased comment

Fixes: QTBUG-117932
Pick-to: 6.6
Change-Id: I870e92b448dfd1f9864ff94743cf7accc50fc6ff
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

2 files changed, 6 insertions, 6 deletions

diff --git a/src/compositor/hardware_integration/qwltextureorphanage.cpp b/src/compositor/hardware_integration/qwltextureorphanage.cpp
index c1337190a..c1ff86977 100644
--- a/src/compositor/hardware_integration/qwltextureorphanage.cpp
+++ b/src/compositor/hardware_integration/qwltextureorphanage.cpp
@@ -42,8 +42,8 @@ void QWaylandTextureOrphanage::admitTexture(QOpenGLTexture *tex, QOpenGLContext
     }
 
     connect(ctx, &QOpenGLContext::aboutToBeDestroyed, this,
-            &QWaylandTextureOrphanage::onContextAboutToBeDestroyed,
-            Qt::ConnectionType(Qt::DirectConnection | Qt::UniqueConnection));
+            [this, ctx]() { this->onContextAboutToBeDestroyed(ctx); },
+            Qt::ConnectionType(Qt::DirectConnection));
 }
 
 void QWaylandTextureOrphanage::deleteTextures()
@@ -71,9 +71,8 @@ void QWaylandTextureOrphanage::deleteTextures()
     }
 }
 
-void QWaylandTextureOrphanage::onContextAboutToBeDestroyed()
+void QWaylandTextureOrphanage::onContextAboutToBeDestroyed(QOpenGLContext *ctx)
 {
-    QOpenGLContext *ctx = qobject_cast<QOpenGLContext *>(sender());
     Q_ASSERT(ctx != nullptr);
 
     qCDebug(qLcWTO) << Q_FUNC_INFO << " ctx (" << ctx
@@ -89,7 +88,8 @@ void QWaylandTextureOrphanage::deleteTexturesByContext(QOpenGLContext *ctx)
 {
     // NOTE: We are (by class-internal design) locked (m_containerLock)
     // when we enter this function!
-    // So in a debug-build we will fail below:
+    // If not (e.g.: someone changes something in/around this class),
+    // then in a debug-build we will fail below:
     Q_ASSERT(!m_containerLock.tryLock());
 
     QList<QOpenGLTexture *> texturesToDelete = m_orphanedTextures.values(ctx);
diff --git a/src/compositor/hardware_integration/qwltextureorphanage_p.h b/src/compositor/hardware_integration/qwltextureorphanage_p.h
index d267043e4..1e5298530 100644
--- a/src/compositor/hardware_integration/qwltextureorphanage_p.h
+++ b/src/compositor/hardware_integration/qwltextureorphanage_p.h
@@ -47,7 +47,7 @@ public:
 
 public slots:
     // uses sender() to call deleteTexturesByContext
-    void onContextAboutToBeDestroyed();
+    void onContextAboutToBeDestroyed(QOpenGLContext *ctx);
 
 private:
     void deleteTexturesByContext(QOpenGLContext *ctx);