Fixed crash in step import introduced with rev 38d0870

nurbsSurfacesWithModifiedKnots.TryGetValue the key can't be null.
FriendsOfCADability · Oct 24, 2024 · 69d075f · 69d075f
1 parent 38d0870
commit 69d075f
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/CADability/ImportStep.cs b/CADability/ImportStep.cs
@@ -4238,7 +4238,7 @@ private object CreateEntity(Item item)
                                         }
                                     }
                                 }
-                                if (nurbsSurfacesWithModifiedKnots.TryGetValue(srf as NurbsSurface, out ModOp2D modify2DCurve))
+                                if (srf is NurbsSurface nurbsSurface && nurbsSurfacesWithModifiedKnots.TryGetValue(nurbsSurface, out ModOp2D modify2DCurve))
                                 {
                                     // this nurbs surface doesn't have the original 2d space. Move the 2d curve to the modified 2d space here.
                                     c2d = c2d.GetModified(modify2DCurve);