relinquish the mouse capture when a dialog is about to be made modal to ensure that the mouse can be used in it (patch 1754648)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@48121 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/msgdlg.cpp

@@ -137,6 +137,12 @@ void wxMessageDialog::GTKCreateMsgDialog()
 
 int wxMessageDialog::ShowModal()
 {
+    // break the mouse capture as it would interfere with modal dialog (see
+    // wxDialog::ShowModal)
+    wxWindow * const win = wxWindow::GetCapture();
+    if ( win )
+        win->GTKReleaseMouseAndNotify();
+
     if ( !m_widget )
     {
         GTKCreateMsgDialog();