Do we even have any unit tests for font caching? The problem with Travis here is that the font cache isn't used there at all, I don't think.

The font cache is always used to draw text, and the test suite draws text. On Travis, the font cache is rebuilt from scratch each time. What wedon't have is a test of saving to disk and loading it again. But that should be easy enough to write by calling the various functions in font_manager.py directly from a unit test.

One problem with testing this class is that it searches the filesystem when you call__init__. But I guess we can work around that.

I think it's probably good enough to just save and reload the existing singleton (font_manager.py:fontManager) to a temp file. Thatshouldn't do a lot of file I/O (other than the tempfile). The generation of the cache itself from the font files on the system is already tested (or at least covered) by the existing unit test suite.

@jkseppan: Do you consider this ready to merge? Looks good to me.

I think it should be ready to merge to master, but it's probably too large of a change to add to 1.5.x in the release-candidate phase.

Yes -- definitely not for 1.5.

Master is fair game for 2.1 code.