CoreText: Make sure to keep reference to data when cloning raw font engine

QFontEngine::cloneWithSize() is used by QRawFont internally when switching
a raw-font from one size to another using setPixelSize. For CoreText, we
use a subclass of QCoreTextFontEngine to keep track of the QByteArray data
of a raw-font, but failed to overload cloneWithSize, so we would lose the
data whenever setPixelSize was called, resulting in missing text rendering
in QtWebKit. We now retain the data as we should.

Task-number: QTBUG-65923
Change-Id: I7d4186a3c32a61d48d1e9388e43f2792e8e46081
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/platformsupport/fontdatabases/mac/qfontengine_coretext.mm b/src/platformsupport/fontdatabases/mac/qfontengine_coretext.mm
index 66baf162d9..d96158d8f6 100644
--- a/src/platformsupport/fontdatabases/mac/qfontengine_coretext.mm
+++ b/src/platformsupport/fontdatabases/mac/qfontengine_coretext.mm
@@ -192,6 +192,14 @@ public:
         : QCoreTextFontEngine(font, def)
         , m_fontData(fontData)
     {}
+    QFontEngine *cloneWithSize(qreal pixelSize) const
+    {
+        QFontDef newFontDef = fontDef;
+        newFontDef.pixelSize = pixelSize;
+        newFontDef.pointSize = pixelSize * 72.0 / qt_defaultDpi();
+
+        return new QCoreTextRawFontEngine(cgFont, newFontDef, m_fontData);
+    }
     QByteArray m_fontData;
 };