weird behavior with "[un]setopt monitor"

[Atom Smasher <atom@xxxxxxxxxxx>]

as expected:
 % sleep 30 &
 [1] 47773
 % jobs
 [1]  + running    sleep 30
 % kill %sleep
 [1]  + terminated  sleep 30

somewhat as expected:
 % unsetopt monitor ; sleep 30 & ; setopt monitor
 % jobs
 [1]  + running    sleep 30
 % kill %sleep
 kill: kill %sleep failed: no such process

not at all expected:
 % unsetopt monitor ; sleep 30 & ; setopt monitor
 % jobs
 [1]  + running    sleep 30
 % unsetopt monitor ; kill %sleep
 % jobs
 %

in the first case, i start "sleep 30" in the background. it shows up in 
the jobs table, and can be killed as expected. no surprised there.

in the second case, i start "sleep 30" in the background after unsetting 
the monitor option. after the job is dropped into the background, i reset 
the monitor option. the job is listed in the jobs table, which i didn't 
expect. as expected, it isn't killed in the normal way.

the third example is where things really get weird. i start "sleep 30" in 
the background after unsetting the monitor option. after the job is 
dropped into the background, i reset the monitor option. the job is listed 
in the jobs table, which i didn't expect. so far, the same as the second 
example. but if after i unset the monitor option, i can kill the job with 
kill. not at all what i expected.

is this a bug or an undocumented feature? it seems like an alternate table 
to store jobs in, which is useful. can i take advantage of this feature? 
or is it a bug that will be "fixed"?

thanks...


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