mozilla/shumway — comment on commit dea2d3475cdf53fa2d2b52b9f44a2fe02b3a94c8
File: src/avm2/avm2.js line 55
By tobeytailor:

We should make sure that the high 4 bits of the 5th byte are cleaned, since JavaScript wraps set bits around when left-shifting across 32bit boundary.