2 files changed, 26 insertions, 8 deletions

diff --git a/src/gui/itemviews/qheaderview.cpp b/src/gui/itemviews/qheaderview.cpp
index 5bd82d4..dc63b25 100644
--- a/src/gui/itemviews/qheaderview.cpp
+++ b/src/gui/itemviews/qheaderview.cpp
@@ -1388,8 +1388,7 @@ int QHeaderView::defaultSectionSize() const
 void QHeaderView::setDefaultSectionSize(int size)
 {
     Q_D(QHeaderView);
-    d->defaultSectionSize = size;
-    d->forceInitializing = true;
+    d->setDefaultSectionSize(size);
 }
 
 /*!
@@ -1894,9 +1893,6 @@ void QHeaderView::initializeSections()
         //make sure we update the hidden sections
         if (newCount < oldCount)
             d->updateHiddenSections(0, newCount-1);
-    } else if (d->forceInitializing) {
-        initializeSections(0, newCount - 1);
-        d->forceInitializing = false;
     }
 }
 
@@ -1952,7 +1948,7 @@ void QHeaderView::initializeSections(int start, int end)
     if (!d->sectionHidden.isEmpty())
         d->sectionHidden.resize(d->sectionCount);
 
-    if (d->sectionCount > oldCount || d->forceInitializing)
+    if (d->sectionCount > oldCount)
         d->createSectionSpan(start, end, (end - start + 1) * d->defaultSectionSize, d->globalResizeMode);
     //Q_ASSERT(d->headerLength() == d->length);
 
@@ -3364,6 +3360,29 @@ void QHeaderViewPrivate::cascadingResize(int visual, int newSize)
     viewport->update();
 }
 
+void QHeaderViewPrivate::setDefaultSectionSize(int size)
+{
+    Q_Q(QHeaderView);
+    defaultSectionSize = size;
+    int currentVisualIndex = 0;
+    for (int i = 0; i < sectionSpans.count(); ++i) {
+        QHeaderViewPrivate::SectionSpan &span = sectionSpans[i];
+        if (span.size > 0) {
+            //we resize it if it is not hidden (ie size > 0)
+            const int newSize = span.count * size;
+            if (newSize != span.size) {
+                length += newSize - span.size; //the whole length is changed
+                const int oldSectionSize = span.sectionSize();
+                span.size = span.count * size;
+                for (int i = currentVisualIndex; i < currentVisualIndex + span.count; ++i) {
+                    emit q->sectionResized(logicalIndex(i), oldSectionSize, size);
+                }
+            }
+        }
+        currentVisualIndex += span.count;
+    }
+}
+
 void QHeaderViewPrivate::resizeSectionSpan(int visualIndex, int oldSize, int newSize)
 {
     Q_Q(QHeaderView);
diff --git a/src/gui/itemviews/qheaderview_p.h b/src/gui/itemviews/qheaderview_p.h
index fbba69a..2889f08 100644
--- a/src/gui/itemviews/qheaderview_p.h
+++ b/src/gui/itemviews/qheaderview_p.h
@@ -90,7 +90,6 @@ public:
           highlightSelected(false),
           stretchLastSection(false),
           cascadingResizing(false),
-          forceInitializing(false),
           stretchSections(0),
           contentsSections(0),
           minimumSectionSize(-1),
@@ -275,7 +274,6 @@ public:
     bool highlightSelected;
     bool stretchLastSection;
     bool cascadingResizing;
-    bool forceInitializing;
     int stretchSections;
     int contentsSections;
     int defaultSectionSize;
@@ -310,6 +308,7 @@ public:
     void createSectionSpan(int start, int end, int size, QHeaderView::ResizeMode mode);
     void removeSectionsFromSpans(int start, int end);
     void resizeSectionSpan(int visualIndex, int oldSize, int newSize);
+    void setDefaultSectionSize(int size);
 
     inline int headerSectionCount() const { // for debugging
         int count = 0;