fix crash when ungrouping a group with set-then-unset filter

diff --git a/src/style.cpp b/src/style.cpp
index 4fd8577b94cda5ae84c71cedb17df3d78684c4cb..ad4e509f6c0ca9129ebbaa350c9a35b7e16b0c5b 100644 (file)
--- a/src/style.cpp
+++ b/src/style.cpp
@@ -2197,7 +2197,7 @@ sp_style_merge_ifilter(SPStyle *style, SPIFilter const *parent)
             style->filter.href->changedSignal().connect(sigc::bind(sigc::ptr_fun(sp_style_filter_ref_changed), style));
     }
 
-    if (style->filter.href && parent->href) {
+    if (style->filter.href && parent->href && parent->href->getObject()) {
         try {
             style->filter.href->attach(*parent->href->getURI());
         } catch (Inkscape::BadURIException &e) {