Re-layout QProgressDialog when setting the cancel button

Setting a cancel button on QProgressDialog more than once caused the layout
to be invalid. The layout was only applied when the dialog resizes or the
style changes, but not when a new cancel button is set.

The solution is to update the layout() before showing the dialog when adopting
new child widgets.

Fixes: QTBUG-19983
Pick-to: 6.0 6.1
Change-Id: Id8fb1ac56e94a9bd97d4559a2e8d4835856fd7d0
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/widgets/dialogs/qprogressdialog.cpp b/src/widgets/dialogs/qprogressdialog.cpp
index 32834291b8..448acfc7f9 100644
--- a/src/widgets/dialogs/qprogressdialog.cpp
+++ b/src/widgets/dialogs/qprogressdialog.cpp
@@ -485,6 +485,8 @@ void QProgressDialogPrivate::adoptChildWidget(QWidget *c)
             c->setParent(q, { });
     }
     ensureSizeIsAtLeastSizeHint();
+    //The layout should be updated again to prevent layout errors when the new 'widget' is replaced
+    layout();
     if (c)
         c->show();
 }