[pacman-dev] [PATCH v2 2/2] makepkg: refactor checking for write permissions into a utility function

[Allan McRae]

On 31/10/17 04:03, Eli Schwartz wrote:
> Additionally provide a separate error for the confusing if unlikely
> event that the user tries to use an existing file as a package output
> directory.
> 
> This also means we now consistently try to create any nonexistent *DEST
> directories as needed before aborting with E_FS_PERMISSIONS. Previously
> only $BUILDDIR received that kindness.
> 
> Fixes FS#43537
> 
> Signed-off-by: Eli Schwartz <eschwartz at archlinux.org>
> ---
> 
> mkdir -p has a really bad error when a file exists that conflicts with
> the path to be created. But I'm still not sure whether to include that
> code in ensure_writable_dir
> 
>  scripts/libmakepkg/util/util.sh.in | 19 +++++++++++++++++++
>  scripts/makepkg.sh.in              | 19 ++++++-------------
>  2 files changed, 25 insertions(+), 13 deletions(-)
> 
> diff --git a/scripts/libmakepkg/util/util.sh.in b/scripts/libmakepkg/util/util.sh.in
> index d676249d..8a6149ed 100644
> --- a/scripts/libmakepkg/util/util.sh.in
> +++ b/scripts/libmakepkg/util/util.sh.in
> @@ -83,3 +83,22 @@ cd_safe() {
>  		exit 1
>  	fi
>  }
> +
> +# Try to create directory if one does not yet exist. Fails if the directory
> +# exists but has no write permissions, or if there is an existing file with
> +# the same name.
> +ensure_writable_dir() {
> +	local parent=$1 dirname=$1
> +
> +	until [[ -e $parent ]]; do
> +		parent="${parent%/*}"
> +	done
> +	if [[ -f $parent ]]; then
> +		error "$(gettext "Cannot create %s due to conflicting file.")" "$parent"
> +		return 1
> +	fi
> +	if ( [[ ! -d $dirname ]] && ! mkdir -p "$dirname" ) || [[ ! -w $dirname ]]; then
> +		return 1
> +	fi
> +	return 0
> +}
> diff --git a/scripts/makepkg.sh.in b/scripts/makepkg.sh.in
> index 20cc22ad..35665f16 100644
> --- a/scripts/makepkg.sh.in
> +++ b/scripts/makepkg.sh.in
> @@ -1360,34 +1360,27 @@ else
>  fi
>  
>  
> -if [[ ! -d $BUILDDIR ]]; then
> -	if ! mkdir -p "$BUILDDIR"; then
> -		error "$(gettext "You do not have write permission to create packages in %s.")" "$BUILDDIR"
> -		plain "$(gettext "Aborting...")"
> -		exit 1
> -	fi
> -	chmod a-s "$BUILDDIR"

As discussed on IRC, this chmod is important.   If the build dir gets
created with a sticky bit, that propagates through the package.

A