[pacman-dev] [PATCH] Bump minimum required bash version to 4.2

[Dave Reisner]

On Wed, Nov 04, 2015 at 02:32:09PM -0400, Aaron Campbell wrote:
> 4.1 does not have support for negative subscripts to indexed arrays (a feature
> that makepkg depends on).
> 
> From the bash CHANGES log list of changes between 4.1-release and 4.2-alpha:
> 
>     Negative subscripts to indexed arrays, previously errors, now are treated
>     as offsets from the maximum assigned index + 1.
> 
> Fixes "/usr/bin/makepkg: line 2774: idx: bad array subscript" seen w/ 4.1.
> 
> Signed-off-by: Aaron Campbell <aaron at monkey.org>

If it's only a single instance, it seems to me it'd be simpler to just
fix the usage rather than bump the bash requirement. Negative subscripts
are a convenience feature, not a necessity.

4.2 brings with it support for:

- %(fmt)T printf formatting (roughly strftime)
- backslashes escapes for unicode
- declare -g
- test -v
- lastpipe

Which are essentially all convenience methods for otherwise available
functionality. No strong reason to want this...

> ---
>  configure.ac | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/configure.ac b/configure.ac
> index 359d61b..a8d339c 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -183,18 +183,18 @@ AC_DEFUN([AX_PROG_PERL_VERSION],
>  AX_PROG_PERL_VERSION([5.10.1], [], [AC_MSG_ERROR([perl is too old])])
>  
>  AS_IF([test "x$BASH_SHELL" = "xfalse"],
> -	AC_MSG_WARN([*** bash >= 4.1.0 is required for pacman scripts]),
> +	AC_MSG_WARN([*** bash >= 4.2.0 is required for pacman scripts]),
>  	[bash_version_major=`$BASH_SHELL -c 'echo "${BASH_VERSINFO[[0]]}"'`
>  	bash_version_minor=`$BASH_SHELL -c 'echo "${BASH_VERSINFO[[1]]}"'`
>  	ok=yes
>  	if test "$bash_version_major" -lt 4; then
>  		ok=no
>  	fi
> -	if test "$bash_version_major" -eq 4 && test "$bash_version_minor" -lt 1; then
> +	if test "$bash_version_major" -eq 4 && test "$bash_version_minor" -lt 2; then
>  		ok=no
>  	fi
>  	if test "$ok" = "no"; then
> -		AC_MSG_ERROR([*** bash >= 4.1.0 is required for pacman scripts])
> +		AC_MSG_ERROR([*** bash >= 4.2.0 is required for pacman scripts])
>  	fi
>  	unset bash_version_major bash_version_minor ok])
>  
> -- 
> 2.5.0