Re: [PATCH] scripts/setlocalversion: fix a bug when LOCALVERSION is empty

[Greg Kroah-Hartman]

On Mon, Jul 12, 2021 at 10:00:59AM -0400, Mikulas Patocka wrote:
> The patch 042da426f8ebde012be9429ff705232af7ad7469 
> ("scripts/setlocalversion: simplify the short version part") reduces the 
> indentation. Unfortunatelly, it also changes behavior in a subtle way - if 
> the user has empty "LOCALVERSION" variable, the plus sign is appended to 
> the kernel version. It wasn't appended before.
> 
> This patch reverts to the old behavior - we append the plus sign only if
> the LOCALVERSION variable is not set.
> 
> Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
> Fixes: 042da426f8eb ("scripts/setlocalversion: simplify the short version part")
> 
> ---
>  scripts/setlocalversion |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: linux-2.6/scripts/setlocalversion
> ===================================================================
> --- linux-2.6.orig/scripts/setlocalversion	2021-07-12 15:29:07.000000000 +0200
> +++ linux-2.6/scripts/setlocalversion	2021-07-12 15:50:29.000000000 +0200
> @@ -131,7 +131,7 @@ res="${res}${CONFIG_LOCALVERSION}${LOCAL
>  if test "$CONFIG_LOCALVERSION_AUTO" = "y"; then
>  	# full scm version string
>  	res="$res$(scm_version)"
> -elif [ -z "${LOCALVERSION}" ]; then
> +elif [ "${LOCALVERSION+set}" != "set" ]; then

That's really subtle, can you add a comment here that this handles an
empty file?

thanks,

greg k-h