1 files changed, 9 insertions, 0 deletions
diff --git a/src/quick/scenegraph/qsgdefaultglyphnode_p.cpp b/src/quick/scenegraph/qsgdefaultglyphnode_p.cpp
index 39d9832f58..bf92bf8b39 100644
--- a/src/quick/scenegraph/qsgdefaultglyphnode_p.cpp
+++ b/src/quick/scenegraph/qsgdefaultglyphnode_p.cpp
@@ -480,6 +480,12 @@ void QSGTextMaskMaterial::init(int cacheType)
     QOpenGLContext *ctx = const_cast<QOpenGLContext *>(QOpenGLContext::currentContext());
     Q_ASSERT(ctx != 0);
 
+    // The following piece of code will read/write to the font engine's caches,
+    // potentially from different threads. However, this is safe because this
+    // code is only called from QQuickItem::updatePaintNode() which is called
+    // only when the GUI is blocked, and multiple threads will call it in
+    // sequence. See also QSGRenderContext::invalidate
+
     QRawFontPrivate *fontD = QRawFontPrivate::get(m_font);
     if (fontD->fontEngine != 0) {
         if (cacheType < 0) {
@@ -494,6 +500,9 @@ void QSGTextMaskMaterial::init(int cacheType)
             m_glyphCache = new QOpenGLTextureGlyphCache(QFontEngineGlyphCache::Type(cacheType),
                                                         QTransform());
             fontD->fontEngine->setGlyphCache(ctx, m_glyphCache.data());
+            QSGRenderContext *sg = QSGRenderContext::from(ctx);
+            Q_ASSERT(sg);
+            sg->registerFontengineForCleanup(fontD->fontEngine);
         }
     }
 }