Re: [gentoo-portage-dev] [PATCH] ebuild: set up bash compat levels

[Ulrich Mueller]

>>>>> On Tue, 10 Nov 2015, Mike Frysinger wrote:

> +	# Set the compat level in case things change with newer ones.  We must not
> +	# export this into the env otherwise we might break  other shell scripts we
> +	# execute (e.g. ones in /usr/bin).
> +	BASH_COMPAT="${maj}.${min}"
> +
> +	# The variable above is new to bash-4.3.  For older versions, we have to use
> +	# a compat knob.  Further, the compat knob only exists with older versions
> +	# (e.g. bash-4.3 has compat42 but not compat43).  This means we only need to
> +	# turn the knob with older EAPIs, and only when running newer bash versions:
> +	# there is no bash-3.3 (it went 3.2 to 4.0), and when requiring bash-4.2, the
> +	# var works with bash-4.3+, and you don't need to set compat to 4.2 when you
> +	# are already running 4.2.
> +	if __eapi_bash_3_2 && [[ ${BASH_VERSINFO[0]} -gt 3 ]] ; then
> +		shopt -s compat32
> +	fi

Wouldn't this profit from an additional test for <bash-4.3? If I
understood the upstream discussion correctly, they were thinking about
dropping the compat* options in some future version?

That is, the conditional should look like:

	if __eapi_bash_3_2 \
			&& [[ ${BASH_VERSINFO[0]} -eq 4 \
			&& ${BASH_VERSINFO[1]} -lt 3 ]] ; then
		shopt -s compat32
	fi

Ulrich