Nested brace expansion results in too many parameters

[whitelynx]

When expanding nested brace expansions, some elements get expanded too many times.

In fish:

> echo test-{foo,ba{r,z}}
test-foo test-bar test-foo test-baz

In bash:

$ echo test-{foo,ba{r,z}}
test-foo test-bar test-baz

[ridiculousfish]

Thank you for reporting this. Should be fixed with commit e9d216b