[Chart] Problem with upgrade to diagrams 1.0

[Brent Yorgey]

On Tue, Feb 11, 2014 at 12:22:25AM +1100, Tim Docker wrote:
> Hi Brent,
> 
> The chart library seem to have a problem with filled arcs after the
> upgrade of diagrams from 0.7 to 1.0:
> 
> https://github.com/timbod7/haskell-chart/issues/19
> 
> Before I dive in to investigate further, have you any pointers to
> semantic changes in diagrams that might affect such output?

Hi Tim,

I don't know of any semantic changes along these lines (there were
some related semantic changes going from 0.6 to 0.7, but
Chart-diagrams worked with diagrams 0.7 from the outset).

Instead, I suspect this may be related to

  https://github.com/diagrams/diagrams-svg/issues/43

Unfortunately it's a bit hard to confirm whether this is indeed the
culprit.  It depends on the specific diagram tree constructed by
Chart-diagrams---in particular whether a fill attribute is placed at
the root of a subtree containing both the circles and some
lines---perhaps the lines connecting the circles?  But even without
absolutely verifying it, everything seems to fit.

Unrelatedly, we did actually just add Typeable constraints as
mentioned in that ticket, so fixing this should not be too hard.

-Brent