Revert "QHeaderView: relayout on resetDefaultSectionSize"

This reverts commit a8df174369cecd90f14dac85bf162353b7cb25d1.

Reason for revert: Caused QTBUG-122109

Pick-to: 6.5 6.6 6.7
Fixes: QTBUG-122109
Fixes: QTBUG-120699
Change-Id: Iea185c00f35e17d8eb8e8da70dc2d808ea274b04
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

2 files changed, 14 insertions, 13 deletions

diff --git a/src/widgets/itemviews/qheaderview.cpp b/src/widgets/itemviews/qheaderview.cpp
index 2bc6a84f37..9ce09dbacc 100644
--- a/src/widgets/itemviews/qheaderview.cpp
+++ b/src/widgets/itemviews/qheaderview.cpp
@@ -1519,14 +1519,13 @@ void QHeaderView::setDefaultSectionSize(int size)
     if (size < 0 || size > maxSizeSection)
         return;
     d->setDefaultSectionSize(size);
-    d->customDefaultSectionSize = true;
 }
 
 void QHeaderView::resetDefaultSectionSize()
 {
     Q_D(QHeaderView);
     if (d->customDefaultSectionSize) {
-        d->setDefaultSectionSize(d->getDefaultSectionSizeFromStyle());
+        d->updateDefaultSectionSizeFromStyle();
         d->customDefaultSectionSize = false;
     }
 }
@@ -2378,7 +2377,7 @@ bool QHeaderView::event(QEvent *e)
         break; }
     case QEvent::StyleChange:
         if (!d->customDefaultSectionSize)
-            d->setDefaultSectionSize(d->getDefaultSectionSizeFromStyle());
+            d->updateDefaultSectionSizeFromStyle();
         break;
     default:
         break;
@@ -3845,6 +3844,7 @@ void QHeaderViewPrivate::setDefaultSectionSize(int size)
     executePostedLayout();
     invalidateCachedSizeHint();
     defaultSectionSize = size;
+    customDefaultSectionSize = true;
     if (state == QHeaderViewPrivate::ResizeSection)
         preventCursorChangeInSetOffset = true;
     for (int i = 0; i < sectionItems.size(); ++i) {
@@ -3865,14 +3865,15 @@ void QHeaderViewPrivate::setDefaultSectionSize(int size)
     viewport->update();
 }
 
-int QHeaderViewPrivate::getDefaultSectionSizeFromStyle() const
+void QHeaderViewPrivate::updateDefaultSectionSizeFromStyle()
 {
-    Q_Q(const QHeaderView);
-    return orientation == Qt::Horizontal
-            ? q->style()->pixelMetric(QStyle::PM_HeaderDefaultSectionSizeHorizontal, nullptr, q)
-            : qMax(q->minimumSectionSize(),
-                   q->style()->pixelMetric(QStyle::PM_HeaderDefaultSectionSizeVertical, nullptr,
-                                           q));
+    Q_Q(QHeaderView);
+    if (orientation == Qt::Horizontal) {
+        defaultSectionSize = q->style()->pixelMetric(QStyle::PM_HeaderDefaultSectionSizeHorizontal, nullptr, q);
+    } else {
+        defaultSectionSize = qMax(q->minimumSectionSize(),
+                                  q->style()->pixelMetric(QStyle::PM_HeaderDefaultSectionSizeVertical, nullptr, q));
+    }
 }
 
 void QHeaderViewPrivate::recalcSectionStartPos() const // linear (but fast)
@@ -4181,7 +4182,7 @@ bool QHeaderViewPrivate::read(QDataStream &in)
     if (in.status() == QDataStream::Ok) {  // we haven't read past end
         customDefaultSectionSize = tmpbool;
         if (!customDefaultSectionSize)
-            defaultSectionSize = getDefaultSectionSizeFromStyle();
+            updateDefaultSectionSizeFromStyle();
     }
 
     lastSectionSize = -1;
diff --git a/src/widgets/itemviews/qheaderview_p.h b/src/widgets/itemviews/qheaderview_p.h
index 7600f7a677..8b214e1d03 100644
--- a/src/widgets/itemviews/qheaderview_p.h
+++ b/src/widgets/itemviews/qheaderview_p.h
@@ -148,7 +148,7 @@ public:
 
     inline void setDefaultValues(Qt::Orientation o) {
         orientation = o;
-        defaultSectionSize = getDefaultSectionSizeFromStyle();
+        updateDefaultSectionSizeFromStyle();
         defaultAlignment = (o == Qt::Horizontal
                             ? Qt::Alignment(Qt::AlignCenter)
                             : Qt::AlignLeft|Qt::AlignVCenter);
@@ -323,7 +323,7 @@ public:
     void removeSectionsFromSectionItems(int start, int end);
     void resizeSectionItem(int visualIndex, int oldSize, int newSize);
     void setDefaultSectionSize(int size);
-    int getDefaultSectionSizeFromStyle() const;
+    void updateDefaultSectionSizeFromStyle();
     void recalcSectionStartPos() const; // not really const
 
     inline int headerLength() const { // for debugging