[pacman-dev] [PATCH 6/6] makepkg: safely change directories

[Dave Reisner]

On Fri, Mar 09, 2012 at 05:59:09PM +1000, Allan McRae wrote:
> In preparation for the removal of the global error trap we need a
> way to ensure changing directories succeeds.  Add a "cd_safe"
> wrapper that performs the necessary check.
> 
> Signed-off-by: Allan McRae <allan at archlinux.org>
> ---
>  scripts/makepkg.sh.in |   40 ++++++++++++++++++++++++----------------
>  1 file changed, 24 insertions(+), 16 deletions(-)
> 
> diff --git a/scripts/makepkg.sh.in b/scripts/makepkg.sh.in
> index 534f6f8..f21c638 100644
> --- a/scripts/makepkg.sh.in
> +++ b/scripts/makepkg.sh.in
> @@ -874,6 +874,14 @@ error_function() {
>  	exit 2 # $E_BUILD_FAILED
>  }
>  
> +cd_safe() {
> +	if ! cd "$1"; then

Do we want to write stdout to /dev/null here? It _should_ be quiet since
we unset CDPATH early on...

> +		error "$(gettext "Failed to change to directory %s")" "$1"
> +		plain "$(gettext "Aborting...")"
> +		exit 1
> +	fi
> +}
> +
>  run_function() {
>  	if [[ -z $1 ]]; then
>  		return 1
> @@ -891,7 +899,7 @@ run_function() {
>  	fi
>  
>  	msg "$(gettext "Starting %s()...")" "$pkgfunc"
> -	cd "$srcdir"
> +	cd_safe "$srcdir"
>  
>  	# ensure all necessary build variables are exported
>  	export CFLAGS CXXFLAGS LDFLAGS MAKEFLAGS CHOST
> @@ -969,7 +977,7 @@ run_package() {
>  }
>  
>  tidy_install() {
> -	cd "$pkgdir"
> +	cd_safe "$pkgdir"
>  	msg "$(gettext "Tidying install...")"
>  
>  	if [[ $(check_option docs) = "n" && -n ${DOC_DIRS[*]} ]]; then
> @@ -1219,7 +1227,7 @@ write_pkginfo() {
>  }
>  
>  check_package() {
> -	cd "$pkgdir"
> +	cd_safe "$pkgdir"
>  
>  	# check existence of backup files
>  	local file
> @@ -1248,7 +1256,7 @@ create_package() {
>  
>  	check_package
>  
> -	cd "$pkgdir"
> +	cd_safe "$pkgdir"
>  	msg "$(gettext "Creating package...")"
>  
>  	local nameofpkg
> @@ -1407,7 +1415,7 @@ create_srcpackage() {
>  
>  	# tar it up
>  	msg2 "$(gettext "Compressing source package...")"
> -	cd "${srclinks}"
> +	cd_safe "${srclinks}"
>  	if ! bsdtar -c${TAR_OPT}Lf "$pkg_file" ${pkgbase}; then
>  		error "$(gettext "Failed to create source package file.")"
>  		exit 1 # TODO: error code
> @@ -1423,7 +1431,7 @@ create_srcpackage() {
>  		warning "$(gettext "Failed to create symlink to source package file.")"
>  	fi
>  
> -	cd "${startdir}"
> +	cd_safe "${startdir}"
>  	rm -rf "${srclinks}"
>  }
>  
> @@ -1757,7 +1765,7 @@ devel_check() {
>  			fi
>  			msg "$(gettext "Determining latest %s revision...")" 'hg'
>  			if [[ -d ./src/$_hgrepo ]] ; then
> -				cd ./src/$_hgrepo
> +				cd_safe ./src/$_hgrepo
>  				local ret=0
>  				hg pull || ret=$?
>  				if (( ! ret )); then
> @@ -1768,10 +1776,10 @@ devel_check() {
>  			else
>  				[[ ! -d ./src/ ]] && mkdir ./src/
>  				hg clone $_hgroot/$_hgrepo ./src/$_hgrepo
> -				cd ./src/$_hgrepo
> +				cd_safe ./src/$_hgrepo
>  			fi
>  			newpkgver=$(hg tip --template "{rev}")
> -			cd ../../
> +			cd_safe ../../
>  		fi
>  
>  		if [[ -n $newpkgver ]]; then
> @@ -1847,7 +1855,7 @@ canonicalize_path() {
>  
>  	if [[ -d $path ]]; then
>  		(
> -			cd "$path"
> +			cd_safe "$path"
>  			pwd -P
>  		)
>  	else
> @@ -2171,7 +2179,7 @@ fi
>  if (( GENINTEG )); then
>  	mkdir -p "$srcdir"
>  	chmod a-s "$srcdir"
> -	cd "$srcdir"
> +	cd_safe "$srcdir"
>  	download_sources
>  	generate_checksums
>  	exit 0 # $E_OK
> @@ -2321,14 +2329,14 @@ if (( SOURCEONLY )); then
>  	# Get back to our src directory so we can begin with sources.
>  	mkdir -p "$srcdir"
>  	chmod a-s "$srcdir"
> -	cd "$srcdir"
> +	cd_safe "$srcdir"
>  	if ( (( ! SKIPCHECKSUMS )) || \
>  			( (( ! SKIPPGPCHECK )) && source_has_signatures ) ) || \
>  			(( SOURCEONLY == 2 )); then
>  		download_sources
>  	fi
>  	check_source_integrity
> -	cd "$startdir"
> +	cd_safe "$startdir"
>  
>  	# if we are root or if fakeroot is not enabled, then we don't use it
>  	if [[ $(check_buildenv fakeroot) != "y" ]] || (( EUID == 0 )); then
> @@ -2384,7 +2392,7 @@ umask 0022
>  # get back to our src directory so we can begin with sources
>  mkdir -p "$srcdir"
>  chmod a-s "$srcdir"
> -cd "$srcdir"
> +cd_safe "$srcdir"
>  
>  if (( NOEXTRACT )); then
>  	warning "$(gettext "Skipping source retrieval        -- using existing %s tree")" "src/"
> @@ -2420,7 +2428,7 @@ else
>  	fi
>  	mkdir -p "$pkgdir"
>  	chmod a-s "$pkgdir"
> -	cd "$startdir"
> +	cd_safe "$startdir"
>  
>  	# if we are root or if fakeroot is not enabled, then we don't use it
>  	if [[ $(check_buildenv fakeroot) != "y" ]] || (( EUID == 0 )); then
> @@ -2450,7 +2458,7 @@ else
>  			devel_update
>  			(( BUILDFUNC )) && run_build
>  			(( CHECKFUNC )) && run_check
> -			cd "$startdir"
> +			cd_safe "$startdir"
>  		fi
>  
>  		enter_fakeroot
> -- 
> 1.7.9.3
> 
>