OpenSCADimport: fixed centering of linear extrude

src/Mod/OpenSCAD/importCSG.py

@@ -567,12 +567,12 @@ def p_linear_extrude_with_twist(p):
     else :
         obj = p[6][0]
     if t:
-        newobj = [process_linear_extrude_with_twist(obj,h,t)]
+        newobj = process_linear_extrude_with_twist(obj,h,t)
     else:
-        newobj = [process_linear_extrude(obj,h)]
+        newobj = process_linear_extrude(obj,h)
     if p[3]['center']=='true' :
        center(newobj,0,0,h)
-    p[0] = newobj
+    p[0] = [newobj]
     if printverbose: print "End Linear Extrude with twist"
 
 def p_import_file1(p):