[csswg-drafts] Pull Request: [cssom] Check index for rule insertion first

upsuper has just submitted a new pull request for 
https://github.com/w3c/csswg-drafts:

== [cssom] Check index for rule insertion first ==
Fixes #753.

See https://github.com/w3c/csswg-drafts/pull/754

Received on Thursday, 24 November 2016 00:44:18 UTC