Widgets/Styles: pass correct style option struct to subelements

QHeaderView is using QStyleOptionHeaderV2 which should later be used in
the subelements drawings. But since the subelement rect must be
adjusted, a copy is done - sadly only to QStyleOptionHeader so we're
loosing the V2 information.
Therefore explicitly check if it's a V2 and copy it over to the correct
structure.

Pick-to: 6.5 6.2
Fixes: QTBUG-97571
Change-Id: I1482f118e2114cd6ef21c2a800785bd9910c1c5b
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/src/widgets/styles/qcommonstyle.cpp b/src/widgets/styles/qcommonstyle.cpp
index f4a8d1f1ea..28731aaca1 100644
--- a/src/widgets/styles/qcommonstyle.cpp
+++ b/src/widgets/styles/qcommonstyle.cpp
@@ -2183,7 +2183,13 @@ void QCommonStyle::drawControl(ControlElement element, const QStyleOption *opt,
             QRegion clipRegion = p->clipRegion();
             p->setClipRect(opt->rect);
             proxy()->drawControl(CE_HeaderSection, header, p, widget);
-            QStyleOptionHeader subopt = *header;
+            // opt can be a QStyleOptionHeaderV2 and we must pass it to the subcontrol drawings
+            QStyleOptionHeaderV2 subopt;
+            QStyleOptionHeader &v1Copy = subopt;
+            if (auto v2 = qstyleoption_cast<const QStyleOptionHeaderV2 *>(opt))
+                subopt = *v2;
+            else
+                v1Copy = *header;
             subopt.rect = subElementRect(SE_HeaderLabel, header, widget);
             if (subopt.rect.isValid())
                 proxy()->drawControl(CE_HeaderLabel, &subopt, p, widget);