"if cval" in rc_params()

Hi, I am trying to add a pdf compression level parameter to

    > the rc file, with possible values 0 (no compression) or 1
    > to 9 (as in gzip). If I make the default nonzero but set
    > the value to 0 in my rc file, the default takes over. It
    > seems to me that the two "if cval" tests in rc_params
    > should be changed to "if cval is not None"; but would this
    > have unintended consequences?

I took a quick look, and 'if cval is not None' looks right to me too.