[Buildroot] [PATCH 1/1] package/fakedate: Skip other fakedates in PATH

[Yann E. MORIN <yann.morin.1998@free.fr>]

Mark, All,

On 2020-04-20 18:56 +0000, Mark Huang spake thusly:
> If multiple buildroot SDKs are in PATH before /usr/bin (usually accidentally,
> but there may be some valid use cases for this), the first two copies of
> fakedate will go into a loop calling each other without ever finding
> /usr/bin/date. Grep for SOURCE_DATE_EPOCH in the candidate date binary, for
> additional verification that it's not another copy of fakedate.
> 
> Signed-off-by: Mark Huang <mark.huang@cerebras.net>
> ---
>  package/fakedate/fakedate | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/package/fakedate/fakedate b/package/fakedate/fakedate
> index a64d9b9..7b04568 100755
> --- a/package/fakedate/fakedate
> +++ b/package/fakedate/fakedate
> @@ -23,7 +23,7 @@ DATE_BIN=false
>  # Instead, find path of true `date' binary.
>  for P in `echo $PATH | tr ':' ' '`; do
>      if [ -x "$P/date" ]; then
> -        if ! [ "$P/date" -ef "$0" ]; then
> +        if ! [ "$P/date" -ef "$0" ] && ! grep -q SOURCE_DATE_EPOCH "$P/date" ; then

Thanks for this patch. I don't think this to be reliable enough, though.

Instead, what you want is iterate over PATH until you find ${0}, and
then take the next 'date' that matches, something like (to be tested!):

    # Find the 'date' executable that comes *after* us in PATH, to avoid
    # inifinite recursion:
    found_self=false
    for P in `echo $PATH | tr ':' ' '`; do
        if [ -x "$P/date"]; then
            ${found_self} && { DATE_BIN="$P/date"; break; }
            [ "$P/date" -ef "$0" ] && found_self=true
        fi
    done

Can you lok into tht, and respin, please? In the meantime, I've marked
the patch as chagnes requested in patchwork.

Regards,
Yann E. MORIN.

>              DATE_BIN="$P/date"
>              break;
>          fi
> --
> 1.8.3.1
> 
> 
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