bash 4, subshells and ERR

[Ian Fitchet]

Hi,

 ERR is notionally triggered when a simple command fails.  Subshells
are both compound commands and do not inherit ERR.  This is what I
expect (read: am used to):

3.2.0% trap 'echo SIGERR' ERR
3.2.0% ( false; )
3.2.0%

 However, now I see:

4.1.0% trap 'echo SIGERR' ERR
4.1.0% ( false; )
SIGERR
4.1.0%

 I'm not saying it's a bad thing only that it's different and not
documented.

 There's also a comment in the 4.1 CHANGES regarding ((:

j.  The [[ and (( commands are now subject to the setting of `set -e'
and the
    ERR trap.

 which made me wonder if something had changed regard compound
commands across the piece.

 (( i=0 )) now triggers the ERR trap.  That (( returned non-zero when
the expression evaluated to zero always struck me as a feature but as
a compound command it never triggered ERR.  Now it might become
inconvenient! :-)

Cheers,

Ian