[BUG] incorrect exit status from subshell on bash with --enable-minimal-config

[Martijn Dekker]

On bash with --enable-minimal-config, as of version 4.3 (as far as I can
tell), there appears to be a bug with the exit status on returning from
subshells. Apparently the exit status of the subshell is not given to
the main shell.

On bash-4.4 with --enable-minimal-config:
$ (false);echo $?
0
$ (false);echo $?
0
$ (false);echo $?
0

On bash-4.4 with --enable-minimal-config --enable-alias:
$ (false);echo $?
1
$ (false);echo $?
0
$ (false);echo $?
0

Note the difference in behaviour: if --enable-alias is used it acts
correctly but only once.

On bash-4.3 the behaviour is identical. bash-4.2 doesn't compile on my
system so I was unable to test it. On bash-4.1 and bash-4.0 the bug is
not present. Testing was done on Mac OS X 10.11.6.

Thanks,

- Martijn