tdf#118573: Acquire solar mutex when calling Application::Reschedule

Change-Id: I252973ad5902738c2bb684f6bb70bc4c46500bae
Reviewed-on: https://gerrit.libreoffice.org/62873
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
diff --git a/vcl/win/window/salframe.cxx b/vcl/win/window/salframe.cxx
index 9829896..068e1a3 100644
--- a/vcl/win/window/salframe.cxx
+++ b/vcl/win/window/salframe.cxx
@@ -5686,7 +5686,10 @@
                // messages in the message queue and dispatch them before we return control to the system.

                if ( nRet )
                {
                    SolarMutexGuard aGuard;
                    while ( Application::Reschedule( true ) );
                }
            }
            else
            {