Award criteria for ALL cohort - WHERE clause broken

The code to award a badge when the criteria requires being a member of multiple cohorts is broken.

It appears that the WHERE clause that's generated when seeing if a person is a member of ALL required cohorts doesn't work.

In criteria/award_criteria_cohort line 247ish reads:

$where = ' AND cm.cohortid = :cohortid'.$i;

When I believe it should read:

$where .= ' AND cm.cohortid = :cohortid'.$i;

So a person could gain the badge if they were only a member of the last cohort, not all cohorts, because the AND clause only includes the last cohortid.

I was looking at MDL-63120 and ran across this line, which I'm pretty sure is just a simple oversight bug, but I'm definitely not a) a php programmer or b) overly familiar with the cohort award code.