vclref: protect vs. double disposes.

Change-Id: I86fe17ad9afba7ee1e87aaa732bebee1746c140f

svtools/source/control/ruler.cxx

@@ -334,9 +334,14 @@ void Ruler::dispose()
     if ( mnUpdateEvtId )
         Application::RemoveUserEvent( mnUpdateEvtId );
     delete mpSaveData;
+    mpSaveData = NULL;
     delete mpDragData;
+    mpDragData = NULL;
     if( pAccContext )
+    {
         pAccContext->release();
+        pAccContext = NULL;
+    }
     Window::dispose();
 }
 

svx/source/dialog/svxruler.cxx

@@ -353,11 +353,16 @@ void SvxRuler::dispose()
 
     pBindings->EnterRegistrations();
 
-    for(sal_uInt16 i = 0; i < CTRL_ITEM_COUNT  && pCtrlItem[i]; ++i)
-        delete pCtrlItem[i];
-    delete[] pCtrlItem;
+    if (pCtrlItem)
+    {
+        for(sal_uInt16 i = 0; i < CTRL_ITEM_COUNT  && pCtrlItem[i]; ++i)
+            delete pCtrlItem[i];
+        delete[] pCtrlItem;
+        pCtrlItem = NULL;
+    }
 
     pBindings->LeaveRegistrations();
+
     Ruler::dispose();
 }