Re: [PATCH] filter-branch: use sh -c instead of eval

[Johannes Sixt <johannes.sixt@telecom.at>]

Matthias Lederhofer wrote:

> If filters use variables with the same name as variables
> used in the script the script breaks.  Executing the filters
> in a separate process prevents accidential modification of
> the variables in the main process.
> @@ -349,21 +349,21 @@ while read commit; do
>  
>  eval "$(set_ident AUTHOR <../commit)"
>  eval "$(set_ident COMMITTER <../commit)"
> -     eval "$filter_env" < /dev/null
> +     sh -c "$filter_env" < /dev/null

NACK.

The eval is on purpose here. $filter_env must be able export GIT_AUTHOR* and
GIT_COMMITTER* variables here.

Generally, it might be useful that one filter sets or exports variables that
are then available for subsequent filters or the next commit. Therefore, I
think it's actually a feature to have eval instead of sh -c even if there
is a chance that the filter overwrites internal variables. 

-- Hannes