QTextEdit::ExtraSelection failure with style sheets

the feature has to handle text with and without background, and extra
selections with and without background, or even only with underline style.
Trouble is that you sometimes want to accumulate styles, for example spell
checking wiggly underline plus search result highlights or background markup
from the css stylesheet.

Task-number: 252310

2 files changed, 39 insertions, 6 deletions

diff --git a/src/gui/text/qtextformat.h b/src/gui/text/qtextformat.h
index 0571d75..8eaeeb1 100644
--- a/src/gui/text/qtextformat.h
+++ b/src/gui/text/qtextformat.h
@@ -232,6 +232,12 @@ public:
         ImageWidth = 0x5010,
         ImageHeight = 0x5011,
 
+        // internal
+        /*
+           SuppressText = 0x5012,
+           SuppressBackground = 0x513
+        */
+
         // selection properties
         FullWidthSelection = 0x06000,
 
diff --git a/src/gui/text/qtextlayout.cpp b/src/gui/text/qtextlayout.cpp
index 434d1ca..3222237 100644
--- a/src/gui/text/qtextlayout.cpp
+++ b/src/gui/text/qtextlayout.cpp
@@ -61,6 +61,8 @@
 QT_BEGIN_NAMESPACE
 
 #define ObjectSelectionBrush (QTextFormat::ForegroundBrush + 1)
+#define SuppressText 0x5012
+#define SuppressBackground 0x513
 
 static inline QFixed leadingSpaceWidth(QTextEngine *eng, const QScriptLine &line)
 {
@@ -1143,6 +1145,7 @@ void QTextLayout::draw(QPainter *p, const QPointF &pos, const QVector<FormatRang
     }
 
     QPainterPath excludedRegion;
+    QPainterPath needsTextButNoBackground;
     for (int i = 0; i < selections.size(); ++i) {
         FormatRange selection = selections.at(i);
         const QBrush bg = selection.format.background();
@@ -1211,14 +1214,35 @@ void QTextLayout::draw(QPainter *p, const QPointF &pos, const QVector<FormatRang
         selection.format.setProperty(QTextFormat::BackgroundBrush, QBrush());
         selection.format.clearProperty(QTextFormat::OutlinePen);
 
+        bool noText = (selection.format.foreground().style() == Qt::NoBrush);
+
+        selection.format.setProperty(SuppressText, noText);
+
         for (int line = firstLine; line < lastLine; ++line) {
             QTextLine l(line, d);
             l.draw(p, position, &selection);
         }
         p->restore();
 
-        if (selection.format.foreground().style() != Qt::NoBrush) // i.e. we have drawn text
-            excludedRegion += region;
+        if (noText)
+            needsTextButNoBackground += region;
+        else
+            needsTextButNoBackground -= region;
+        excludedRegion += region;
+    }
+
+    if (!needsTextButNoBackground.isEmpty()){
+        p->save();
+        p->setClipPath(needsTextButNoBackground, Qt::IntersectClip);
+        FormatRange selection;
+        selection.start = 0;
+        selection.length = INT_MAX;
+        selection.format.setProperty(SuppressBackground, true);
+        for (int line = firstLine; line < lastLine; ++line) {
+            QTextLine l(line, d);
+            l.draw(p, position, &selection);
+        }
+        p->restore();
     }
 
     if (!excludedRegion.isEmpty()) {
@@ -1912,14 +1936,17 @@ static void drawMenuText(QPainter *p, QFixed x, QFixed y, const QScriptItem &si,
 static void setPenAndDrawBackground(QPainter *p, const QPen &defaultPen, const QTextCharFormat &chf, const QRectF &r)
 {
     QBrush c = chf.foreground();
-    if (c.style() == Qt::NoBrush)
+    if (c.style() == Qt::NoBrush) {
         p->setPen(defaultPen);
+    }
 
     QBrush bg = chf.background();
-    if (bg.style() != Qt::NoBrush)
+    if (bg.style() != Qt::NoBrush && !chf.property(SuppressBackground).toBool())
         p->fillRect(r, bg);
-    if (c.style() != Qt::NoBrush)
+    if (c.style() != Qt::NoBrush) {
         p->setPen(QPen(c, 0));
+    }
+
 }
 
 /*!
@@ -1933,7 +1960,7 @@ void QTextLine::draw(QPainter *p, const QPointF &pos, const QTextLayout::FormatR
     const QScriptLine &line = eng->lines[i];
     QPen pen = p->pen();
 
-    bool noText = (selection && selection->format.foreground().style() == Qt::NoBrush);
+    bool noText = (selection && selection->format.property(SuppressText).toBool());
 
     if (!line.length) {
         if (selection