[Merge][#111665] bzr rm should remove clean subtrees

[Andrew Bennetts]

Alexander Belchenko wrote:
[...]
> >          files = [f for f in new_files]
> 
> ^-- does list comprehension is faster than slicing operation?
> My simple test shows that is not:
> 
> E:\Bazaar\mydev\selftest.miss.dep>python -m timeit "a = range(1000); b = [i for i in a]"
> 1000 loops, best of 3: 381 usec per loop
> 
> E:\Bazaar\mydev\selftest.miss.dep>python -m timeit "a = range(1000); b = a[:]"
> 10000 loops, best of 3: 86.7 usec per loop

A better test is:

    python -m timeit -s "a = range(1000)" "b = [i for i in a]"
    python -m timeit -s "a = range(1000)" "b = a[:]"

> If my test is reliable then I suggest to change the line above to
> 
>           files = new_files[:]

More readable (and faster) is:

    files = list(new_files)

-Andrew.