ofz#10395 Null-dereference

Change-Id: I7bde5987a51949d60174335327652186e0ad8998
Reviewed-on: https://gerrit.libreoffice.org/60559Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

oox/source/shape/WpsContext.cxx

@@ -179,11 +179,14 @@ oox::core::ContextHandlerRef WpsContext::onCreateContext(sal_Int32 nElementToken
         if (rAttribs.hasAttribute(XML_prst))
         {
             uno::Reference<beans::XPropertySet> xPropertySet(mxShape, uno::UNO_QUERY);
-            oox::OptValue<OUString> presetShapeName = rAttribs.getString(XML_prst);
-            const OUString& preset = presetShapeName.get();
-            comphelper::SequenceAsHashMap aCustomShapeGeometry(xPropertySet->getPropertyValue("CustomShapeGeometry"));
-            aCustomShapeGeometry["PresetTextWarp"] <<= preset;
-            xPropertySet->setPropertyValue("CustomShapeGeometry", uno::makeAny(aCustomShapeGeometry.getAsConstPropertyValueList()));
+            if (xPropertySet.is())
+            {
+                oox::OptValue<OUString> presetShapeName = rAttribs.getString(XML_prst);
+                const OUString& preset = presetShapeName.get();
+                comphelper::SequenceAsHashMap aCustomShapeGeometry(xPropertySet->getPropertyValue("CustomShapeGeometry"));
+                aCustomShapeGeometry["PresetTextWarp"] <<= preset;
+                xPropertySet->setPropertyValue("CustomShapeGeometry", uno::makeAny(aCustomShapeGeometry.getAsConstPropertyValueList()));
+            }
         }
         break;
     case XML_txbx: