Do not try to construct an ustring from NULL in CurveDragPoint::_getTip.

Fixes crasher.

diff --git a/src/ui/tool/curve-drag-point.cpp b/src/ui/tool/curve-drag-point.cpp
index dbd19c754f63dbf90de34c5da70cff2bfb47a40e..0d1183ebf92a8bde407d2bafe705097555b7cfdf 100644 (file)
--- a/src/ui/tool/curve-drag-point.cpp
+++ b/src/ui/tool/curve-drag-point.cpp
@@ -154,7 +154,7 @@ bool CurveDragPoint::_doubleclickedHandler(GdkEventButton *event)
 
 Glib::ustring CurveDragPoint::_getTip(unsigned state)
 {
-    if (!first || !first.next()) return NULL;
+    if (!first || !first.next()) return "";
     bool linear = first->front()->isDegenerate() && first.next()->back()->isDegenerate();
     if (state_held_shift(state)) {
         return C_("Path segment statusbar tip",