Related: tdf#92392 clear some more vclptrs on dispose

Change-Id: I91b8d082ff19328e35e2f1c2a02838d96224dc9c
(cherry picked from commit 8e20a253)
Reviewed-on: https://gerrit.libreoffice.org/16831Reviewed-by: Michael Meeks <michael.meeks@collabora.com>
Tested-by: Michael Meeks <michael.meeks@collabora.com>

sc/source/ui/miscdlgs/anyrefdg.cxx

@@ -83,6 +83,11 @@ void ScFormulaReferenceHelper::dispose()
         pInputHdl->ResetDelayTimer();   // stop the timer for disabling the input line
 
     pAccel.reset();
+
+    mpOldEditParent.clear();
+    m_pWindow.clear();
+    pRefBtn.clear();
+    pRefEdit.clear();
 }
 
 void ScFormulaReferenceHelper::enableInput( bool bEnable )