Is there a function Fixup[]?

Questions
1

In the source code for the CDF demonstration on Fractal Curves, Roman Maeder uses a statement tt=Fixup[t]. Mathematica accepts this statement but I cannot find any documentation on the ?Function? The source is as follows:

SetAttributes[Curve, Flat]
Curve /: r_c _Curve := r # & /@ c
simplify[c_Curve] := 
 c //. {Curve[Turn[r1_], Turn[r2_]] :> Curve[Turn[r1 + r2]], 
   Curve[Turn[[Angle]_ /; [Angle] == 0.0]] :> Curve[]}
Iterate[c_Curve, template_Curve] := c /. Move[l_] :> l template
Iterate[c_Curve, template : {__Curve}] := 
 c /. Move[l_, n_: 1] :> l template[[n]]
Move /: l_Move[l1, args___] := Move[l l1, args]
Turn /: l_Turn[a_] := Turn[a]
Fractal[c_Curve, t_, n_Integer ?NonNegative] := 
 With[{tt = Fixup[t]}, Nest[Iterate[#, tt] &, c, n]]
Manipulate[examples; 
 Graphics[Fractal[ex[[1]], ex[[2]], n], 
  ImageSize -> {450, 400}], {{n, 3, "iterations"}, 0, 5, 1, 
  Appearance -> "Labeled"}, {{ex, examples[[1]], "replacement curves",
    ControlType -> SetterBar}, 
  Thread[examples -> {Graphics[Fractal[#[[1]], #[[2]], 1], 
        ImageSize -> {70, 70}] & /@ examples}], 
  ControlType -> SetterBar}, SaveDefinitions -> True]

and I get an error in the Fractal function call that I am trying to understand.

The CDF runs fine.

2

If you download the “Author Code” from the link in the upper right hand side of

http://demonstrations.wolfram.com/FractalCurves/

or use this link (which is the link from that page)

http://demonstrations.wolfram.com/downloadauthornb.cgi?name=FractalCurves

Then Open all cells in the notebook’s section called “Initialization Code” and you will see the definition of all the functions used in the demonstration–including the Fixup function that he defines there.

3

If you download the “Author Code” from the link in the upper right hand side of

http://demonstrations.wolfram.com/FractalCurves/

or use this link (which is the link from that page)

http://demonstrations.wolfram.com/downloadauthornb.cgi?name=FractalCurves

Then Open all cells in the notebook’s section called “Initialization Code” and you will see the definition of all the functions used in the demonstration–including the Fixup function that he defines there.