[macruby-changes] [MacRuby/MacRuby] 998999: fix the MatchData#[] behavior if passed a negative...

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/MacRuby/MacRuby
  Commit: 998999953decfd1162cef517fa87498e99897c21
      https://github.com/MacRuby/MacRuby/commit/998999953decfd1162cef517fa87498e99897c21
  Author: Watson <watson1978 at gmail.com>
  Date:   2012-08-27 (Mon, 27 Aug 2012)

  Changed paths:
    M re.c

  Log Message:
  -----------
  fix the MatchData#[] behavior if passed a negative Fixnum object as index

In below case, MatchData#[] always returns a nil:

	index < 0 &&
		(matched count) + index >= 0

Sample code:

```
str = 'foo bar baz'
m = str.match(/\w+/)
p m[-1]  #=> expect "foo", but nil
```

This fix above behavior.