Description of problem:
I've got a tcsh that's consuming 100% cpu while doing nothing obvious.  Up to this point, I had been starting 20+ jobs in the background, and as each one stopped for keyboard input, I'd type 'fg' and give them some.

Version-Release number of selected component (if applicable):
tcsh-6.17-11.fc14.i686

How reproducible:
Not tried.

Steps to Reproduce:
1. Start 20 background tasks with a foreach loop
  foreach n (`cat .alist`)
    ssh -n $n xlogo > $n &
  end
2. Get notices about jobs stopping because they need keyboard input, in this case, "host not found in known_hosts file, are you sure?"
3. Type 'fg' for each, type 'yes'
  
Actual results:
It worked for most of the jobs, but at the end, I got this:

...
ssh -n 137.82.128.93 xlogo
The authenticity of host '137.82.128.93 (<no hostip for proxy command>)' can't be established.
RSA key fingerprint is 00:12:22:8c:f6:8b:01:b8:43:89:a1:ea:07:50:9c:b7.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '137.82.128.93' (RSA) to the list of known hosts.
^CKilled by signal 2.
kirk:/tmp> fg
ssh -n 137.82.128.82 xlogo
The authenticity of host '137.82.128.82 (<no hostip for proxy command>)' can't be established.
RSA key fingerprint is 22:20:ac:e1:f1:9a:2b:a2:d1:ea:02:b2:d0:ad:2f:57.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '137.82.128.82' (RSA) to the list of known hosts.
^CKilled by signal 2.
kirk:/tmp> fg
ssh -n 137.82.128.107 xlogo
fg: No such job.
kirk:/tmp> fg

^C^C^Z^\



Expected results:
It should 'just work'...


Additional info:
It looks like the code that keeps track of the background jobs got
confused about how many jobs were in the list (due to asynchronous
updates as jobs ended), and it went past the end of the list.  It may
need more error checking to prevent a race condition, I guess.