I actually don't mind the original redouble. The "standard" meaning where I play is that redoubling the opponent's takeout double shows 10/11+ points. Partner's double is suggesting a penalty, but I would certainly take it out and bid 2♠ here, with a good 6 card suit and a partial fit for partner. Partner shouldn't read that sequence as showing anything in particular in hearts, in my opinion (redouble does not show takeout shape for anyone I have played with, though I suppose someone might play it as 4-4 majors or some such).