With the recent thin trading in BRCD it's difficult to determine if this stealth rally means anything. Low volume means that either buyers or sellers of the moment can easily push the stock either way.
The stock could still be all over the board prior to earnings (or a Q2 warning). We'll see.
I doubt that Brocade is in the market buying stock. If you review the historical record, their buyback pattern is erratic and makes little sense. The only time I've seen smart buying was after the stock tanked in late 2011. Even then the average price showed that they failed to buy near the actual low.
Now if you were the folks at BRCD and you knew the earnings would be good and you had a buy back program would you not buy the shares now instead of after the news later? that is what I think is happening, in my opinion.