Match fontEngine glyph cache key to lifespan of owner

The glyph cache key is based on the RHI instance. We clean up the font
cache when the QSGRenderContext is deleted.

For a regular QQuickWindow this is effectively the same. For a
QQuickWidget the RHI instance has a lifespan of the parent widget, but
the render context changes.

Task-number: QTBUG-113426
Task-number: QTBUG-112306
Pick-to: 6.6 6.5
Change-Id: Ifd901ace6caaff9a08352901956865f5f58e06ef
Reviewed-by: Laszlo Agocs <[email protected]>

2 files changed, 3 insertions, 2 deletions

diff --git a/src/quick/scenegraph/qsgdefaultglyphnode_p.cpp b/src/quick/scenegraph/qsgdefaultglyphnode_p.cpp
index 5c4fe767eb..e9e6c26d88 100644
--- a/src/quick/scenegraph/qsgdefaultglyphnode_p.cpp
+++ b/src/quick/scenegraph/qsgdefaultglyphnode_p.cpp
@@ -369,7 +369,8 @@ void QSGTextMaskMaterial::updateCache(QFontEngine::GlyphFormat glyphFormat)
         qreal devicePixelRatio;
         void *cacheKey;
         Q_ASSERT(m_rhi);
-        cacheKey = m_rhi;
+        Q_ASSERT(m_rc);
+        cacheKey = m_rc;
         // Get the dpr the modern way. This value retrieved via the
         // rendercontext matches what RenderState::devicePixelRatio()
         // exposes to the material shaders later on.
diff --git a/src/quick/scenegraph/qsgdefaultrendercontext.cpp b/src/quick/scenegraph/qsgdefaultrendercontext.cpp
index cd0a5b6d28..462196927b 100644
--- a/src/quick/scenegraph/qsgdefaultrendercontext.cpp
+++ b/src/quick/scenegraph/qsgdefaultrendercontext.cpp
@@ -110,7 +110,7 @@ void QSGDefaultRenderContext::invalidate()
     // sequence. (see qsgdefaultglyphnode_p.cpp's init())
     for (QSet<QFontEngine *>::const_iterator it = m_fontEnginesToClean.constBegin(),
          end = m_fontEnginesToClean.constEnd(); it != end; ++it) {
-        (*it)->clearGlyphCache(m_rhi);
+        (*it)->clearGlyphCache(this);
         if (!(*it)->ref.deref())
             delete *it;
     }