Hello,

In version 5.9 the [[ ]] operator is behaving unexpectedly for the
following case:

$ watch ls &
$ [ $(jobs -l | wc -l) -gt 0 ] && echo jobs found || echo no jobs
jobs found
$ [[ $(jobs -l | wc -l) -gt 0 ]] && echo jobs found || echo no jobs
no jobs

Expected

The result should be the same, in this case, with both [ ] and [[ ]].
Actual

[[ $(jobs -l | wc -l) -gt 0 ]] exit status is > 0 when there are jobs
running.
Version information

   - Zsh zsh 5.9 (x86_64-pc-linux-gnu)

Previous version, 5.8.1 was working as expected.
Distros

Tested in the following distros

   - Arch Linux (bare metal, docker)
   - Debian Sid (docker)

-- 
Paulo Diovani Gonçalves,
blog.diovani.com / @paulodiovani <http://twitter.com/paulodiovani>