toolkit: avoid deadlock in UnoControl::setDesignMode()

Avoid deadlock by disposing the accesibility context without the Mutex
locked, since it will eventually try to acquire the SolarMutex...

Thread 1 in UnoControl::getPosSize()
calling from sdr::contact::ControlHolder::getPosSize()

Thread 2 calling from UnoControl::setDesignMode()
trying to get SolarMutex in VCLXWindow::disposing()

Change-Id: I7d0ffe4fa0f8cd0c48e9b9b5e923ce229f97ca57

1 files changed, 3 insertions, 1 deletions

diff --git a/svx/source/fmcomp/fmgridif.cxx b/svx/source/fmcomp/fmgridif.cxx
index 8d6e0752645d..358328bfc844 100644
--- a/svx/source/fmcomp/fmgridif.cxx
+++ b/svx/source/fmcomp/fmgridif.cxx
@@ -787,7 +787,9 @@ void SAL_CALL FmXGridControl::setDesignMode(sal_Bool bOn) throw( RuntimeExceptio
         // dispose our current AccessibleContext, if we have one
         // (changing the design mode implies having a new implementation for this context,
         // so the old one must be declared DEFUNC)
-        disposeAccessibleContext();
+        DisposeAccessibleContext(
+                Reference<XComponent>(maAccessibleContext, UNO_QUERY));
+        maAccessibleContext.clear();
 
         // prepare firing an event
         aModeChangeEvent.Source = *this;