Re: [gentoo-dev] [PATCH v2 4/5] vcs-snapshot.eclass: Detect and report invalid directory structure

[Michał Górny]

On Thu, 2019-07-25 at 09:37 +0200, Michał Górny wrote:
> Detect when the archive does not contain a single top-level directory,
> and abort in that case.  Otherwise, --strip-components would result
> in unpredictable mess.
>
> Signed-off-by: Michał Górny <mgorny@g.o>
> ---
>  eclass/vcs-snapshot.eclass | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/eclass/vcs-snapshot.eclass b/eclass/vcs-snapshot.eclass
> index 312e9a4611e1..33abd9a7c190 100644
> --- a/eclass/vcs-snapshot.eclass
> +++ b/eclass/vcs-snapshot.eclass
> @@ -1,87 +1,100 @@
>  # Copyright 1999-2019 Gentoo Authors
>  # Distributed under the terms of the GNU General Public License v2
>
>  # @ECLASS: vcs-snapshot.eclass
>  # @MAINTAINER:
>  # mgorny@g.o
>  # @SUPPORTED_EAPIS: 0 1 2 3 4 5 6 7
>  # @BLURB: support eclass for unpacking VCS snapshot tarballs
>  # @DESCRIPTION:
>  # THIS ECLASS IS NOT NECESSARY FOR MODERN GITHUB AND GITLAB SNAPSHOTS.
>  # THEIR DIRECTORY STRUCTURE IS ENTIRELY PREDICTABLE, SO UPDATE YOUR
>  # EBUILD TO USE /ARCHIVE/ URI AND SET S IF NECESSARY.
>  #
>  # This eclass provides a convenience src_unpack() which does unpack all
>  # the tarballs in SRC_URI to locations matching their (local) names,
>  # discarding the original parent directory.
>  #
>  # The typical use case are VCS tag snapshots coming from BitBucket
>  # (but not GitHub or GitLab).  They have hash appended to the directory
>  # name which makes extracting them a painful experience.  But if you are
>  # using a SRC_URI arrow to rename them (which quite likely you have to
>  # do anyway), vcs-snapshot will just extract them into matching
>  # directories.
>  #
>  # Please note that this eclass handles only tarballs (.tar, .tar.gz,
>  # .tar.bz2 & .tar.xz).  For any other file format (or suffix) it will
>  # fall back to regular unpack.  Support for additional formats may be
>  # added in the future if necessary.
>  #
>  # @EXAMPLE:
>  #
>  # @CODE
>  # EAPI=7
>  # inherit vcs-snapshot
>  #
>  # SRC_URI="
>  #    https://bitbucket.org/foo/bar/get/${PV}.tar.bz2 -> ${P}.tar.bz2
>  #    https://bitbucket.org/foo/bar-otherstuff/get/${PV}.tar.bz2
>  #        -> ${P}-otherstuff.tar.bz2"
>  # @CODE
>  #
>  # and however the tarballs were originally packed, all files will appear
>  # in ${WORKDIR}/${P} and ${WORKDIR}/${P}-otherstuff respectively.
>
>  case ${EAPI:-0} in
>  	0|1|2|3|4|5|6|7) ;;
>  	*) die "vcs-snapshot.eclass API in EAPI ${EAPI} not yet established."
>  esac
>
>  EXPORT_FUNCTIONS src_unpack
>
>  # @FUNCTION: vcs-snapshot_src_unpack
>  # @DESCRIPTION:
>  # Extract all the archives from ${A}. The .tar, .tar.gz, .tar.bz2
>  # and .tar.xz archives will be unpacked to directories matching their
>  # local names. Other archive types will be passed down to regular
>  # unpack.
>  vcs-snapshot_src_unpack() {
>  	debug-print-function ${FUNCNAME} "${@}"
>
>  	local f
>
>  	for f in ${A}
>  	do
>  		case "${f}" in
>  			*.tar|*.tar.gz|*.tar.bz2|*.tar.xz)
>  				local destdir=${WORKDIR}/${f%.tar*}
>
>  				debug-print "${FUNCNAME}: unpacking ${f} to ${destdir}"
>
> -				# XXX: check whether the directory structure inside is
> -				# fine? i.e. if the tarball has actually a parent dir.
> +				local l topdirs=()
> +				while read l; do

Oh, and please imagine you see '-r' here.

> +					topdirs+=( "${l}" )
> +				done < <(tar -t -f "${DISTDIR}/${f}" | cut -d/ -f1 | sort -u)
> +				if [[ ${#topdirs[@]} -gt 1 ]]; then
> +					eerror "The archive ${f} contains multiple or no top directory."
> +					eerror "It is impossible for vcs-snapshot to unpack this correctly."
> +					eerror "Top directories found:"
> +					local d
> +					for d in "${topdirs[@]}"; do
> +						eerror "    ${d}"
> +					done
> +					die "${FUNCNAME}: Invalid directory structure in archive ${f}"
> +				fi
> +
>  				mkdir "${destdir}" || die
>  				# -o (--no-same-owner) to avoid restoring original owner
>  				einfo "Unpacking ${f}"
>  				tar -C "${destdir}" -x -o --strip-components 1 \
>  					-f "${DISTDIR}/${f}" || die
>  				;;
>  			*)
>  				debug-print "${FUNCNAME}: falling back to unpack for ${f}"
>
>  				# fall back to the default method
>  				unpack "${f}"
>  				;;
>  		esac
>  	done
>  }

-- 
Best regards,
Michał Górny