[pacman-dev] [PATCH v3 2/2] makepkg: refactor checking for write permissions into a utility function

[Eli Schwartz]

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>
---

v3: rebase against escondida's error codes patch

Also re-add the erroneously removed `chmod a-s`. Just do this
unconditionally now.

 scripts/libmakepkg/util/util.sh.in | 19 +++++++++++++++++++
 scripts/makepkg.sh.in              | 20 +++++++-------------
 2 files changed, 26 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 1191e4ec..c9c80bca 100644
--- a/scripts/makepkg.sh.in
+++ b/scripts/makepkg.sh.in
@@ -1359,34 +1359,28 @@ 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 $E_FS_PERMISSIONS
-	fi
-	chmod a-s "$BUILDDIR"
-fi
-if [[ ! -w $BUILDDIR ]]; then
+# check that all settings directories are user-writable
+if ! ensure_writable_dir "$BUILDDIR"; then
 	error "$(gettext "You do not have write permission to create packages in %s.")" "$BUILDDIR"
 	plain "$(gettext "Aborting...")"
 	exit $E_FS_PERMISSIONS
 fi
+chmod a-s "$BUILDDIR"
 
-if (( ! (NOBUILD || GENINTEG) )) && [[ ! -w $PKGDEST ]]; then
+if (( ! (NOBUILD || GENINTEG) )) && ! ensure_writable_dir "$PKGDEST"; then
 	error "$(gettext "You do not have write permission to store packages in %s.")" "$PKGDEST"
 	plain "$(gettext "Aborting...")"
 	exit $E_FS_PERMISSIONS
 fi
 
-if [[ ! -w $SRCDEST ]] ; then
+if ! ensure_writable_dir "$SRCDEST" ; then
 	error "$(gettext "You do not have write permission to store downloads in %s.")" "$SRCDEST"
 	plain "$(gettext "Aborting...")"
 	exit $E_FS_PERMISSIONS
 fi
 
 if (( SOURCEONLY )); then
-	if [[ ! -w $SRCPKGDEST ]]; then
+	if ! ensure_writable_dir "$SRCPKGDEST"; then
 		error "$(gettext "You do not have write permission to store source tarballs in %s.")" "$SRCPKGDEST"
 		plain "$(gettext "Aborting...")"
 		exit $E_FS_PERMISSIONS
@@ -1397,7 +1391,7 @@ if (( SOURCEONLY )); then
 	IGNOREARCH=1
 fi
 
-if (( LOGGING )) && [[ ! -w $LOGDEST ]]; then
+if (( LOGGING )) && ! ensure_writable_dir "$LOGDEST"; then
 	error "$(gettext "You do not have write permission to store logs in %s.")" "$LOGDEST"
 	plain "$(gettext "Aborting...")"
 	exit $E_FS_PERMISSIONS
-- 
2.15.1