Re: [gentoo-portage-dev] [PATCH 3/4] ecompress: Detect and report colliding (un)compressed files

[Zac Medico]

On 09/28/2018 12:55 AM, Michał Górny wrote:
> Whenever the install directory contains files that would collide upon
> (re)compressing, report them explicitly and fail.  This indicates
> a serious problem in ebuild and since we don't know which of the files
> is correct, we should not attempt to choose between them.
>
> To reduce performance impact, the check is only done whenever compressed
> files are found.  This is sufficient since for issue to occur there must
> be at least one compressed variant.
>
> Bug: https://bugs.gentoo.org/667072
> Signed-off-by: Michał Górny <mgorny@g.o>
> ---
>  bin/ecompress | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/bin/ecompress b/bin/ecompress
> index 36bdb585b..bc1f5e08a 100755
> --- a/bin/ecompress
> +++ b/bin/ecompress
> @@ -49,6 +49,30 @@ while [[ $# -gt 0 ]] ; do
>  				find_args+=( -size "+${PORTAGE_DOCOMPRESS_SIZE_LIMIT}c" )
>
>  			while IFS= read -d '' -r path; do
> +				# detect the horrible posibility of the ebuild installing
> +				# colliding compressed and/or uncompressed variants
> +				# and fail hard (bug #667072)
> +				#
> +				# note: to save time, we need to do this only if there's
> +				# at least one compressed file
> +				case ${path} in
> +					*.Z|*.gz|*.bz2|*.lzma|*.xz)
> +						vpath=${path%.*}
> +						for comp in '' .Z .gz .bz2 .lzma .xz; do
> +							if [[ ${vpath}${comp} != ${path} && \
> +									-e ${vpath}${comp} ]]; then
> +								eerror "Colliding files found for ecompress:"
> +								eerror
> +								eerror "  ${path#${D%/}}"
> +								eerror "  ${vpath#${D%/}}${comp}"
> +								eerror
> +								eerror "Please remove the incorrect of those files."
> +								die "Aborting due to colliding compressed files."
> +							fi
> +						done
> +						;;
> +				esac
> +
>  				>> "${path}.ecompress" || die
>  			done < <(find "${find_args[@]}" -print0 || die)
>  		fi
>

This breaks compatibility, so let's use eqawarn and simply leave the
compressed files in place for now, then make it die in the next EAPI.
-- 
Thanks,
Zac