scipy/scipy — pull request #3767 by ewmoore (2014-07-02 02:42:32+00:00)
Title: ENH/BUG: support negative m in elliptic integrals

Prior, ellipkinc, and ellipeinc silently returned garbage for
negative m. Both functions are still inaccurate due at extremely
large phi.

I can upload some measurements on the accuracy for negative m tomorrow, but it seems to be fine.

Maybe this fixes gh-1431, if we're saying that's about negative m, or not if that's for complex support.