New hopper behavior is inconsistent between single and double chests

In the 1.9.1 prereleases, hoppers gained the ability to pull items from blocked chests. However, this behavior is functioning very inconsistently between single and double chests.

To reproduce:

1) Make a single chest and fill it with stuff.
2) Put a block above it to "block" it from opening.
3) Put a hopper below it--it will correctly pull items out.
4) Make a separate double chest and fill it with stuff. Repeat #2 and #3 with this chest--the hopper will fail to pull items out this time.
5) Repeat steps #1 through #3 with a single chest. While the hopper is pulling items, place another chest next to the first to convert it into a double chest--the hopper will continue to pull items out, even though it doesn't with a chest that was originally doubled.

I'm guessing hoppers are now supposed to be able to pull items out of blocked double-chests all the time, but the bug is that they don't if the chest was double to begin with and blocked off.