cesanta/v7 — pull request #20 by mmikulicic (2014-12-04 17:34:58+00:00)
Title: Fix test for negative `substr*`start

Doc sasys "If either argument is less than 0 or is NaN, it is treated as if
it were 0."
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/substring

Trusted MDN, didn't check spec itself.

Tested with:

- node -e "console.log('test'.substr(-200))"