scenario: variable rename + add new variable use

[mndrix]

Imagine code that starts like this:

foo
bar
baz

One branch renames bar to barr:

foo
barr
baz

Another branch invokes bar again.

foo
bar
baz
bar

The correct merge result is:

foo
barr
baz
barr

I suspect that most VCS tools will "successfully" merge but produce a compiler error or incorrect output. Darcs is perhaps the exception since it has first class replace patches.