Fix QTextEdit cursor rectangle vertical positioning

When there are characters with different pointsize in QScriptLine,
the value of si.descent is less than sl.descent, which will cause
the y value of the cursor rectangle to be too large.
If si.descent is less than sl.descent, the height of the cursor
rectangle is equal to base plus si.descent.
Amends e99a883bd382ca950192bd66cafb2a1de6394ce7

Fixes: QTBUG-96288
Done-with: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Pick-to: 6.1 6.2
Change-Id: I4a8566b32cfa75d8ca1a584f5e8e577c5c9caf0d
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 5 insertions, 2 deletions

diff --git a/src/gui/text/qtextlayout.cpp b/src/gui/text/qtextlayout.cpp
index 70e6043231..ad5e827bdd 100644
--- a/src/gui/text/qtextlayout.cpp
+++ b/src/gui/text/qtextlayout.cpp
@@ -1289,13 +1289,16 @@ void QTextLayout::drawCursor(QPainter *p, const QPointF &pos, int cursorPosition
 
     QFixed base = sl.base();
     QFixed descent = sl.descent;
+    QFixed cursorDescent = descent;
     bool rightToLeft = d->isRightToLeft();
     if (itm >= 0) {
         const QScriptItem &si = d->layoutData->items.at(itm);
         if (si.ascent >= 0)
             base = si.ascent;
-        if (si.descent >= 0)
+        if (si.descent == 0)
             descent = si.descent;
+        else if (si.descent > 0 && si.descent < descent)
+            cursorDescent = si.descent;
         rightToLeft = si.analysis.bidiLevel % 2;
     }
     qreal y = position.y() + (sl.y + sl.base() + sl.descent - base - descent).toReal();
@@ -1306,7 +1309,7 @@ void QTextLayout::drawCursor(QPainter *p, const QPointF &pos, int cursorPosition
     QPainter::CompositionMode origCompositionMode = p->compositionMode();
     if (p->paintEngine()->hasFeature(QPaintEngine::RasterOpModes))
         p->setCompositionMode(QPainter::RasterOp_NotDestination);
-    p->fillRect(QRectF(x, y, qreal(width), (base + descent).toReal()), p->pen().brush());
+    p->fillRect(QRectF(x, y, qreal(width), (base + cursorDescent).toReal()), p->pen().brush());
     p->setCompositionMode(origCompositionMode);
     if (toggleAntialiasing)
         p->setRenderHint(QPainter::Antialiasing, false);