bash cannot switch background/foreground for aplay

[Chao Song]

Hi, Bash Developers,

    I found that bash cannot switch background/foreground for aplay.

To reproduce:

    1. run aplay: aplay -Dhw:0,0 -f dat -i -c2 -vvv ./somewave.wav

    2. press CTRL + Z to switch to background

    3. press fg to switch to foreground.  [Failed at this step, seems 
aplay not in foreground, because output for aplay is not resumed.]

   Not sure if this is a bug of aplay or bash, could you please to take 
a look at bash first?

Thanks,

Chao