I was looking through the parser and noticed that default arguments for macro/call parameters aren't attached to the parameter they were defined with. This can lead to unexpected behaviour:

>>> import jinja2
>>> jinja2.Template("{% macro a(b, c=1, d) %}b={{b}},c={{c}},d={{d}}{% endmacro %} {{ a() }}").render()
u' b=,c=,d=1'

Here you can see that the default was applied to parameter d instead of c. There are two fixes for this:

• Tie the defaults to the parameter they were defined from
• Throw a synxtax error like python does: SyntaxError: non-default argument follows default argument