1 files changed, 12 insertions, 6 deletions
diff --git a/src/live_effects/lpe-ruler.cpp b/src/live_effects/lpe-ruler.cpp
index 8d625f88e..c3fc973c2 100644
--- a/src/live_effects/lpe-ruler.cpp
+++ b/src/live_effects/lpe-ruler.cpp
@@ -77,9 +77,12 @@ LPERuler::ruler_mark(Geom::Point const &A, Geom::Point const &n, MarkType const
 
     double real_mark_length = mark_length;
     SPDocument * document = SP_ACTIVE_DOCUMENT;
-    SPNamedView *nv = sp_document_namedview(document, nullptr);
-    Glib::ustring display_unit = nv->display_units->abbr;
-    real_mark_length = Inkscape::Util::Quantity::convert(real_mark_length, unit.get_abbreviation(), display_unit.c_str());
+    SPNamedView *nv = sp_document_namedview(document, NULL);
+    Glib::ustring display_unit = "mm";
+    if (nv && nv->display_units) {
+        display_unit = nv->display_units->abbr;
+        real_mark_length = Inkscape::Util::Quantity::convert(real_mark_length, unit.get_abbreviation(), display_unit.c_str());
+    }
     double real_minor_mark_length = minor_mark_length;
     real_minor_mark_length = Inkscape::Util::Quantity::convert(real_minor_mark_length, unit.get_abbreviation(), display_unit.c_str());
 
@@ -132,9 +135,12 @@ LPERuler::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_i
 
     double real_mark_distance = mark_distance;
     SPDocument * document = SP_ACTIVE_DOCUMENT;
-    SPNamedView *nv = sp_document_namedview(document, nullptr);
-    Glib::ustring display_unit = nv->display_units->abbr;
-    real_mark_distance = Inkscape::Util::Quantity::convert(real_mark_distance, unit.get_abbreviation(), display_unit.c_str());
+    SPNamedView *nv = sp_document_namedview(document, NULL);
+    Glib::ustring display_unit = "mm";
+    if (nv && nv->display_units) {
+        display_unit = nv->display_units->abbr;
+        real_mark_distance = Inkscape::Util::Quantity::convert(real_mark_distance, unit.get_abbreviation(), display_unit.c_str());
+    }
 
     double real_offset = offset;
     real_offset = Inkscape::Util::Quantity::convert(real_offset, unit.get_abbreviation(), display_unit.c_str());