StyleSheet: respect a font weight set for header sections

QCommonStyle sets the font for a selected header section to bold.
This overrides the font weight a calling style might already have set,
e.g. when a style sheet is applied to explicitly set a weight for a
checked header section:

QHeaderView::section:checked {
   font-size: 20px
   font-weight: normal
}

Since setting the weight on a font sets the respective resolve-mask
bit, we can avoid overwriting a weight that is already set explicitly.

Add baseline test coverage using a QTableWidget.

Fixes: QTBUG-122180
Pick-to: 6.7 6.5
Change-Id: I8c6279ad2fd8c5718ebea26e27c64ae823625748
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

3 files changed, 41 insertions, 3 deletions

diff --git a/src/widgets/styles/qcommonstyle.cpp b/src/widgets/styles/qcommonstyle.cpp
index 07682d0ae0..1ab9886796 100644
--- a/src/widgets/styles/qcommonstyle.cpp
+++ b/src/widgets/styles/qcommonstyle.cpp
@@ -1679,9 +1679,12 @@ void QCommonStyle::drawControl(ControlElement element, const QStyleOption *opt,
             QFontMetrics fm(header->fontMetrics);
             if (header->state & QStyle::State_On) {
                 QFont fnt = p->font();
-                fnt.setBold(true);
-                p->setFont(fnt);
-                fm = QFontMetrics((p->font()));
+                // the font already has a weight set; don't override that
+                if (!(fnt.resolveMask() & QFont::WeightResolved)) {
+                    fnt.setBold(true);
+                    p->setFont(fnt);
+                    fm = QFontMetrics((p->font()));
+                }
             }
             QString text = header->text;
             if (const QStyleOptionHeaderV2 *headerV2 = qstyleoption_cast<const QStyleOptionHeaderV2 *>(header)) {
diff --git a/tests/baseline/stylesheet/qss/qheaderview/selectedFontWeight.qss b/tests/baseline/stylesheet/qss/qheaderview/selectedFontWeight.qss
new file mode 100644
index 0000000000..1c45a99767
--- /dev/null
+++ b/tests/baseline/stylesheet/qss/qheaderview/selectedFontWeight.qss
@@ -0,0 +1,16 @@
+QHeaderView::section {
+    background-color: red;
+    font-size: 10px;
+}
+
+QHeaderView::section:checked {
+    background-color: green;
+    font-size: 20px;
+    font-weight: bold;
+}
+
+QHeaderView::section:first {
+    background-color: yellow;
+    font-size: 20px;
+    font-weight: normal;
+}
diff --git a/tests/baseline/stylesheet/tst_baseline_stylesheet.cpp b/tests/baseline/stylesheet/tst_baseline_stylesheet.cpp
index 7f66b8af42..67a618988b 100644
--- a/tests/baseline/stylesheet/tst_baseline_stylesheet.cpp
+++ b/tests/baseline/stylesheet/tst_baseline_stylesheet.cpp
@@ -27,6 +27,9 @@ private slots:
     void tst_QTreeView_data();
     void tst_QTreeView();
 
+    void tst_QHeaderView_data();
+    void tst_QHeaderView();
+
 private:
     QDir styleSheetDir;
 };
@@ -205,6 +208,22 @@ void tst_Stylesheet::tst_QTreeView()
     QBASELINE_CHECK_DEFERRED(takeSnapshot(), "itemSelected");
 }
 
+void tst_Stylesheet::tst_QHeaderView_data()
+{
+    loadTestFiles();
+}
+
+void tst_Stylesheet::tst_QHeaderView()
+{
+    QHBoxLayout *layout = new QHBoxLayout;
+    QTableWidget *tw = new QTableWidget(10, 10);
+    tw->setCurrentCell(1, 1);
+    layout->addWidget(tw);
+    testWindow()->setLayout(layout);
+    makeVisible();
+    QBASELINE_TEST(takeSnapshot());
+}
+
 #define main _realmain
 QTEST_MAIN(tst_Stylesheet)
 #undef main