From: Stefan Sperling <stsp@stsp.name>
Subject: Re: regress common.sh: POSIX arithmetic for trim_obj_id()
To: Christian Weisgerber <naddy@mips.inka.de>
Cc: gameoftrees@openbsd.org
Date: Wed, 16 Sep 2020 22:01:22 +0200

On Wed, Sep 16, 2020 at 07:37:01PM +0200, Christian Weisgerber wrote:
> Replace ksh syntax with POSIX arithmetic expressions.
> 
> This one had me puzzled.  How did the while condition ever work?
> Apparently, variables are expanded without '$' for arithmetic(!)
> comparisons inside [[ ... ]] and in our (k)sh this behavior accidentally
> leaks out to [ ... ].
> 
> Mark the variables as "local" while here.  Actually, "local" isn't
> part of the POSIX shell language, but it's used pervasively in these
> scripts and seems widely supported in practice.
> 
> ok?

Yes, ok.

I think this is a case where I bashed my head against a wall until
I somehow got it working, without giving any consideration to POSIX.

> diff 0429cd76586cecb81d322546ab686ce527eb8f83 /home/naddy/got
> blob - e95df3908f366957e8608730cd2dc49e62155ac0
> file + regress/cmdline/common.sh
> --- regress/cmdline/common.sh
> +++ regress/cmdline/common.sh
> @@ -96,13 +96,13 @@ git_show_tree()
>  
>  trim_obj_id()
>  {
> -	let trimcount=$1
> -	id=$2
> +	local trimcount=$1
> +	local id=$2
>  
> -	pat=""
> -	while [ trimcount -gt 0 ]; do
> +	local pat=""
> +	while [ "$trimcount" -gt 0 ]; do
>  		pat="[0-9a-f]$pat"
> -		let trimcount--
> +		trimcount=$((trimcount - 1))
>  	done
>  
>  	echo ${id%$pat}
> -- 
> Christian "naddy" Weisgerber                          naddy@mips.inka.de
> 
>