fixed bug (toIndex = -1) when used in combination with grouping

[elineopsommer]

No description provided.

[skrajewski]

Hi @elineopsommer,

Could you provide an example with this bug? It will be very helpful to understand what is the problem.

I cannot merge your changes directly - your PR contains to many changes. You should keeping existing code standards without reformatting the whole script. Please apply your fix directly once again, even better when you gather all changes in single commit (in this case).

Thanks in advance,
Szymon

[elineopsommer]

Codepen created: #54