thoughtbot/gitsh — pull request #162 by georgebrock (2014-05-02 19:16:55+00:00)
Title: Mimic sh(1) when handling unset variables.

If an unset variable is used as an argument, it is dropped from the argument list.

For example:

& commit -m $foo
error: switch `m' requires a value
...
& :set foo "This is a commit"
& commit -m $foo
(a commit is created)

This is one possible solution to #136, but @calleerlandsson or @mike-burns might have a better idea.