axis.ticks() returns Arguments object after axis.ticks(count)

[rummelsworth]

d3.svg.axis().ticks().constructor // function Array() { [native code] }
d3.svg.axis().ticks().toString() // "10"

d3.svg.axis().ticks(10).ticks().constructor // function Object() { [native code] }
d3.svg.axis().ticks(10).ticks().toString() // "[object Arguments]"

This bit me when I was feeding an explicit tick spec of an axis to the underlying scale of the axis to get tick values from the scale to manipulate and then feed back to the axis. scale.ticks did not like the Arguments object, giving me [].

The problem is this line in axis.ticks:

tickArguments_ = arguments;

That line should probably look or at least behave like this:

tickArguments_ = Array.prototype.slice.call(arguments);

In any case, an invocation's arguments object shouldn't be exposed to its callers.

[mbostock]

Sounds reasonable.

[mbostock]

Fix merged in #2591.