Fixed QPushButton sizeHint recalculation bug.

This patch causes the size hint of QPushButton to be
recalculated in cases where the value of the autoDefault
property may have changed due to changes in the ancestor
chain.
If not explicitly set, the value of the autoDefault property
depends on the presence of a QDialog ancestor.

Note: The new autotest covers two different use cases related to
this behavior.

Reviewed-by: janarve
Task-number: 255581

2 files changed, 6 insertions, 2 deletions

diff --git a/src/gui/widgets/qpushbutton.cpp b/src/gui/widgets/qpushbutton.cpp
index 7da5930..a1c0d74 100644
--- a/src/gui/widgets/qpushbutton.cpp
+++ b/src/gui/widgets/qpushbutton.cpp
@@ -387,8 +387,9 @@ bool QPushButton::isDefault() const
 QSize QPushButton::sizeHint() const
 {
     Q_D(const QPushButton);
-    if (d->sizeHint.isValid())
+    if (d->sizeHint.isValid() && d->lastAutoDefault == autoDefault())
         return d->sizeHint;
+    d->lastAutoDefault = autoDefault();
     ensurePolished();
 
     int w = 0, h = 0;
@@ -657,6 +658,8 @@ bool QPushButton::event(QEvent *e)
                ) {
 		d->resetLayoutItemMargins();
 		updateGeometry();
+    } else if (e->type() == QEvent::PolishRequest) {
+        updateGeometry();
     }
     return QAbstractButton::event(e);
 }
diff --git a/src/gui/widgets/qpushbutton_p.h b/src/gui/widgets/qpushbutton_p.h
index 0c5ac79..9d682d8 100644
--- a/src/gui/widgets/qpushbutton_p.h
+++ b/src/gui/widgets/qpushbutton_p.h
@@ -65,7 +65,7 @@ public:
 
     QPushButtonPrivate()
         : QAbstractButtonPrivate(QSizePolicy::PushButton), autoDefault(Auto),
-          defaultButton(false), flat(false), menuOpen(false) {}
+          defaultButton(false), flat(false), menuOpen(false), lastAutoDefault(false) {}
 
     inline void init() { resetLayoutItemMargins(); }
     void resetLayoutItemMargins();
@@ -77,6 +77,7 @@ public:
     uint defaultButton : 1;
     uint flat : 1;
     uint menuOpen : 1;
+    mutable uint lastAutoDefault : 1;
 };
 
 QT_END_NAMESPACE