[pacman-dev] [PATCH v2 1/2] makepkg: reorganize the restoration of settings by precedence

[Eli Schwartz]

The extra variables on the commandline were inconsistently applied. They
should override anything else, instead, most were overridden by
environment variables with the exception of BUILDDIR (and this was not
sanity-checked to see if it had write permissions).

e.g. given the commandline:
`PKGDEST="$(pwd)"` BUILDDIR="$(pwd)" makepkg PKGDEST=/doesnt/exist BUILDDIR=/doesnt/exist`

We would incorrectly use the current working directory for PKGDEST.
Meanwhile, we checked the wrong directory for BUILDDIR, and later
errored when we tried to create $srcdir inside the non-writable
directory "/doesnt/exist".

In order to fix this, use the preferred bash builtin for saving variable
definitions, similar to how we restore traps etc. rather than tediously
redefining each one by hand, and restore this immediately after
makepkg.conf is sourced. Finally, the `make`-style commandline overrides
are applied.

Also canonicalize_path is applied only on the final paths we try to use.
While it is unlikely the value in makepkg.conf will be a relative path,
since we now properly respect commandline overrides, they should be
canonicalized as well.

Signed-off-by: Eli Schwartz <eschwartz at archlinux.org>
---
 scripts/makepkg.sh.in | 50 ++++++++++++++++----------------------------------
 1 file changed, 16 insertions(+), 34 deletions(-)

diff --git a/scripts/makepkg.sh.in b/scripts/makepkg.sh.in
index 462ee4bb..20cc22ad 100644
--- a/scripts/makepkg.sh.in
+++ b/scripts/makepkg.sh.in
@@ -1307,17 +1307,8 @@ done
 trap 'trap_exit INT "$(gettext "Aborted by user! Exiting...")"' INT
 trap 'trap_exit USR1 "$(gettext "An unknown error has occurred. Exiting...")"' ERR
 
-# preserve environment variables and canonicalize path
-[[ -n ${PKGDEST} ]] && _PKGDEST=$(canonicalize_path ${PKGDEST})
-[[ -n ${SRCDEST} ]] && _SRCDEST=$(canonicalize_path ${SRCDEST})
-[[ -n ${SRCPKGDEST} ]] && _SRCPKGDEST=$(canonicalize_path ${SRCPKGDEST})
-[[ -n ${LOGDEST} ]] && _LOGDEST=$(canonicalize_path ${LOGDEST})
-[[ -n ${BUILDDIR} ]] && _BUILDDIR=$(canonicalize_path ${BUILDDIR})
-[[ -n ${PKGEXT} ]] && _PKGEXT=${PKGEXT}
-[[ -n ${SRCEXT} ]] && _SRCEXT=${SRCEXT}
-[[ -n ${GPGKEY} ]] && _GPGKEY=${GPGKEY}
-[[ -n ${PACKAGER} ]] && _PACKAGER=${PACKAGER}
-[[ -n ${CARCH} ]] && _CARCH=${CARCH}
+# preserve environment variables to override makepkg.conf
+restore_envvars=$(declare -p PKGDEST SRCDEST SRCPKGDEST LOGDEST BUILDDIR PKGEXT SRCEXT GPGKEY PACKAGER CARCH 2>/dev/null || true)
 
 # default config is makepkg.conf
 MAKEPKG_CONF=${MAKEPKG_CONF:-$confdir/makepkg.conf}
@@ -1342,6 +1333,20 @@ if [[ "$MAKEPKG_CONF" = "$confdir/makepkg.conf" ]]; then
 	fi
 fi
 
+eval "$restore_envvars"
+
+# override settings from extra variables on commandline, if any
+if (( ${#extra_environment[*]} )); then
+	export "${extra_environment[@]}"
+fi
+
+# canonicalize paths and provide defaults if anything is still undefined
+for var in PKGDEST SRCDEST SRCPKGDEST LOGDEST BUILDDIR; do
+	printf -v "$var" "$(canonicalize_path "${!var:-$startdir}")"
+done
+unset var
+PACKAGER=${PACKAGER:-"Unknown Packager"}
+
 # set pacman command if not already defined
 PACMAN=${PACMAN:-pacman}
 # save full path to command as PATH may change when sourcing /etc/profile
@@ -1355,9 +1360,6 @@ else
 fi
 
 
-# override settings with an environment variable for batch processing
-BUILDDIR=${_BUILDDIR:-$BUILDDIR}
-BUILDDIR=${BUILDDIR:-$startdir} #default to $startdir if undefined
 if [[ ! -d $BUILDDIR ]]; then
 	if ! mkdir -p "$BUILDDIR"; then
 		error "$(gettext "You do not have write permission to create packages in %s.")" "$BUILDDIR"
@@ -1372,29 +1374,18 @@ if [[ ! -w $BUILDDIR ]]; then
 	exit 1
 fi
 
-# override settings from extra variables on commandline, if any
-if (( ${#extra_environment[*]} )); then
-	export "${extra_environment[@]}"
-fi
-
-PKGDEST=${_PKGDEST:-$PKGDEST}
-PKGDEST=${PKGDEST:-$startdir} #default to $startdir if undefined
 if (( ! (NOBUILD || GENINTEG) )) && [[ ! -w $PKGDEST ]]; then
 	error "$(gettext "You do not have write permission to store packages in %s.")" "$PKGDEST"
 	plain "$(gettext "Aborting...")"
 	exit 1
 fi
 
-SRCDEST=${_SRCDEST:-$SRCDEST}
-SRCDEST=${SRCDEST:-$startdir} #default to $startdir if undefined
 if [[ ! -w $SRCDEST ]] ; then
 	error "$(gettext "You do not have write permission to store downloads in %s.")" "$SRCDEST"
 	plain "$(gettext "Aborting...")"
 	exit 1
 fi
 
-SRCPKGDEST=${_SRCPKGDEST:-$SRCPKGDEST}
-SRCPKGDEST=${SRCPKGDEST:-$startdir} #default to $startdir if undefined
 if (( SOURCEONLY )); then
 	if [[ ! -w $SRCPKGDEST ]]; then
 		error "$(gettext "You do not have write permission to store source tarballs in %s.")" "$SRCPKGDEST"
@@ -1407,21 +1398,12 @@ if (( SOURCEONLY )); then
 	IGNOREARCH=1
 fi
 
-LOGDEST=${_LOGDEST:-$LOGDEST}
-LOGDEST=${LOGDEST:-$startdir} #default to $startdir if undefined
 if (( LOGGING )) && [[ ! -w $LOGDEST ]]; then
 	error "$(gettext "You do not have write permission to store logs in %s.")" "$LOGDEST"
 	plain "$(gettext "Aborting...")"
 	exit 1
 fi
 
-PKGEXT=${_PKGEXT:-$PKGEXT}
-SRCEXT=${_SRCEXT:-$SRCEXT}
-GPGKEY=${_GPGKEY:-$GPGKEY}
-PACKAGER=${_PACKAGER:-$PACKAGER}
-PACKAGER=${PACKAGER:-"Unknown Packager"} #default if undefined
-CARCH=${_CARCH:-$CARCH}
-
 if (( ! INFAKEROOT )); then
 	if (( EUID == 0 )); then
 		error "$(gettext "Running %s as root is not allowed as it can cause permanent,\n\
-- 
2.15.0