Re: [PATCH v2 4/8] git-prompt: replace [[...]] with standard code

avih [off-list ref] writes:

FWIW, the common form in this file was "[" (46 instances),
then "[[" (13 instances), and finally "test" (3 instances).

Yes, that came from the fact that this file has historically been
considered bash-only and our Bourne shell coding guidelines do not
apply.  

So I'd still think changing "[[" forms into "[" is the better choice
for this file in a compatibility-focused change, as it leaves the
file in a mostly consistent usage of "[" throughout.

Absolutely.  We are in agreement (I said this is a good first step).
I do think making it more consistent after the dust settles (read:
not before the series graduates to 'master') would be a good idea,
though.