Fix possible crash in QStaticText and QDeclarativeTextLayout

The QStaticTextItem held an uncounted reference to QFontEngine. The
pointer would dangle in some cases where there was no font object
referencing the engine and the cache was cleaned out (e.g. when a
new application font is added.) Properly count the reference, and also
add reference counting to userData to make it harder to shoot yourself
in the foot, since the QStaticTextItem class is now being used in
different places,

Task-number: QTBUG-14446
Reviewed-by: Martin Jones

2 files changed, 3 insertions, 3 deletions

diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp
index 8f9d8ba..d4b044b 100644
--- a/src/gui/painting/qpaintengine_raster.cpp
+++ b/src/gui/painting/qpaintengine_raster.cpp
@@ -3300,7 +3300,7 @@ void QRasterPaintEngine::drawStaticTextItem(QStaticTextItem *textItem)
     ensureState();
 
     drawCachedGlyphs(textItem->numGlyphs, textItem->glyphs, textItem->glyphPositions,
-                     textItem->fontEngine);
+                     textItem->fontEngine());
 }
 
 /*!
diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index 7fed7e4..ab9707d 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -5746,7 +5746,7 @@ void QPainterPrivate::drawGlyphs(const quint32 *glyphArray, const QPointF *posit
         QStaticTextItem staticTextItem;
         staticTextItem.color = state->pen.color();
         staticTextItem.font = state->font;
-        staticTextItem.fontEngine = fontEngine;
+        staticTextItem.setFontEngine(fontEngine);
         staticTextItem.numGlyphs = glyphCount;
         staticTextItem.glyphs = reinterpret_cast<glyph_t *>(const_cast<glyph_t *>(glyphArray));
         staticTextItem.glyphPositions = positions.data();
@@ -5938,7 +5938,7 @@ void QPainter::drawStaticText(const QPointF &topLeftPosition, const QStaticText
         d->extended->drawStaticTextItem(item);
 
         drawDecorationForGlyphs(this, item->glyphs, item->glyphPositions,
-                                item->numGlyphs, item->fontEngine, staticText_d->font,
+                                item->numGlyphs, item->fontEngine(), staticText_d->font,
                                 QTextCharFormat());
     }
     if (currentColor != oldPen.color())