"+0" and "-0" at Commit statistics

At the bitbucket website, when I choose the Commits pages and press on an specific commit ID, I can see a summary of the added and removed lines.
When there are not added lines it shows "+0" and when thre are not removed lines it shows "-0", which is clearly incorrect because zero is unsigned.
It seems like a typical case of programming lazyness
It should be at least "0", but I think it would be even more useful to show nothing.