Memory leak with rasterized pcolormesh and savefig

Hi all,

I've come across a memory leak when saving multiple figures in a row.
The figure contains a single pcolormesh artist, which I need to
rasterize in my application. However, turning on rasterization causes
a memory leak.The attached script reproduces the problem; swap out the
commented section at the bottom to eliminate memory growth for each
new figure.

I'm not sure what the cause is, though to toss one idea out, might it
have to do with a references that aren't cleaned up from the
rasterizing part of the mixed-mode renderer?

Tested on Mac OS X and, thanks to Patrick Marsh, on Windows.

Thanks,
Eric

pcolormesh-raster-leak.py (1.02 KB)