Roger,
  I tested the patch and it does seem to function as you describe so feel free to apply the patch.  The tabify function makes me scratch my head a little, according to help.txt:
"Tabify Region       -- Turns *leading* stretches of spaces into tabs
	(Note: We recommend using 4 space blocks to indent Python code.)"

Yet this code doesn't seem to get tabifyed.
a=[1,2,3,4,5]
for i in range(0, len(a)):
 print("%d" % a[i])

I would expect that the print statement be tabbed in but on my Mac it does not seem to do that it just puts back in the single space in front of the print.  This might be a separate issue but I was wondering if perhaps I misunderstand the purpose of this function?