1 files changed, 711 insertions, 0 deletions
diff --git a/test/units/testsuite-15.sh b/test/units/testsuite-15.sh
new file mode 100755
index 0000000..e790b37
--- /dev/null
+++ b/test/units/testsuite-15.sh
@@ -0,0 +1,711 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -eux
+set -o pipefail
+
+# shellcheck source=test/units/test-control.sh
+. "$(dirname "$0")"/test-control.sh
+
+clear_unit() {
+    local unit_name="${1:?}"
+    local base suffix
+
+    systemctl stop "$unit_name" 2>/dev/null || :
+    rm -f  /{etc,run,usr/lib}/systemd/system/"$unit_name"
+    rm -fr /{etc,run,usr/lib}/systemd/system/"$unit_name".d
+    rm -fr /{etc,run,usr/lib}/systemd/system/"$unit_name".{wants,requires}
+    if [[ $unit_name == *@* ]]; then
+        base="${unit_name%@*}"
+        suffix="${unit_name##*.}"
+        systemctl stop "$base@"*."$suffix" 2>/dev/null || :
+        rm -f  /{etc,run,usr/lib}/systemd/system/"$base@"*."$suffix"
+        rm -fr /{etc,run,usr/lib}/systemd/system/"$base@"*."$suffix".d
+        rm -fr /{etc,run,usr/lib}/systemd/system/"$base@"*."$suffix".{wants,requires}
+    fi
+}
+
+clear_units() {
+    for u in "$@"; do
+        clear_unit "$u"
+    done
+    systemctl daemon-reload
+}
+
+create_service() {
+    local service_name="${1:?}"
+    clear_units "${service_name}".service
+
+    cat >/etc/systemd/system/"$service_name".service <<EOF
+[Unit]
+Description=$service_name unit
+
+[Service]
+ExecStart=sleep 100000
+EOF
+    mkdir -p /{etc,run,usr/lib}/systemd/system/"$service_name".service.{d,wants,requires}
+}
+
+create_services() {
+    for u in "$@"; do
+        create_service "$u"
+    done
+}
+
+check_ok() {
+    x="$(systemctl show --value -p "${2:?}" "${1:?}")"
+    case "$x" in
+        *${3:?}*) return 0 ;;
+        *)        return 1 ;;
+    esac
+}
+
+check_ko() {
+    ! check_ok "$@"
+}
+
+testcase_basic_dropins() {
+    echo "Testing basic dropins..."
+
+    echo "*** test a wants b wants c"
+    create_services test15-a test15-b test15-c
+    ln -s ../test15-b.service /etc/systemd/system/test15-a.service.wants/
+    ln -s ../test15-c.service /etc/systemd/system/test15-b.service.wants/
+    check_ok test15-a Wants test15-b.service
+    check_ok test15-b Wants test15-c.service
+
+    echo "*** test a wants,requires b"
+    create_services test15-a test15-b test15-c
+    ln -s ../test15-b.service /etc/systemd/system/test15-a.service.wants/
+    ln -s ../test15-b.service /etc/systemd/system/test15-a.service.requires/
+    check_ok test15-a Wants test15-b.service
+    check_ok test15-a Requires test15-b.service
+
+    echo "*** test a wants nonexistent"
+    create_service test15-a
+    ln -s ../nonexistent.service /etc/systemd/system/test15-a.service.wants/
+    check_ok test15-a Wants nonexistent.service
+    systemctl start test15-a
+    systemctl stop  test15-a
+
+    echo "*** test a requires nonexistent"
+    ln -sf ../nonexistent.service /etc/systemd/system/test15-a.service.requires/
+    systemctl daemon-reload
+    check_ok test15-a Requires nonexistent.service
+
+    # 'b' is already loaded when 'c' pulls it in via a dropin.
+    echo "*** test a,c require b"
+    create_services test15-a test15-b test15-c
+    ln -sf ../test15-b.service /etc/systemd/system/test15-a.service.requires/
+    ln -sf ../test15-b.service /etc/systemd/system/test15-c.service.requires/
+    systemctl start test15-a
+    check_ok test15-c Requires test15-b.service
+    systemctl stop test15-a test15-b
+
+    # 'b'  is already loaded when 'c' pulls it in via an alias dropin.
+    echo "*** test a wants alias"
+    create_services test15-a test15-b test15-c
+    ln -sf test15-c.service /etc/systemd/system/test15-c1.service
+    ln -sf ../test15-c.service  /etc/systemd/system/test15-a.service.wants/
+    ln -sf ../test15-c1.service /etc/systemd/system/test15-b.service.wants/
+    systemctl start test15-a
+    check_ok test15-a Wants test15-c.service
+    check_ok test15-b Wants test15-c.service
+    systemctl stop test15-a test15-c
+
+    echo "*** test service.d/ top level drop-in"
+    create_services test15-a test15-b
+    check_ko test15-a ExecCondition "/bin/echo a"
+    check_ko test15-b ExecCondition "/bin/echo b"
+    mkdir -p /run/systemd/system/service.d
+    cat >/run/systemd/system/service.d/override.conf <<EOF
+[Service]
+ExecCondition=/bin/echo %n
+EOF
+    systemctl daemon-reload
+    check_ok test15-a ExecCondition "/bin/echo test15-a"
+    check_ok test15-b ExecCondition "/bin/echo test15-b"
+    rm -rf /run/systemd/system/service.d
+
+    clear_units test15-{a,b,c,c1}.service
+}
+
+testcase_linked_units() {
+    echo "Testing linked units..."
+    echo "*** test linked unit (same basename)"
+
+    create_service test15-a
+    mv /etc/systemd/system/test15-a.service /
+    ln -s /test15-a.service /etc/systemd/system/
+    ln -s test15-a.service /etc/systemd/system/test15-b.service
+
+    check_ok test15-a Names test15-a.service
+    check_ok test15-a Names test15-b.service
+
+    echo "*** test linked unit (cross basename)"
+
+    mv /test15-a.service /test15-a@.scope
+    ln -fs /test15-a@.scope /etc/systemd/system/test15-a.service
+    systemctl daemon-reload
+
+    check_ok test15-a Names test15-a.service
+    check_ok test15-a Names test15-b.service
+    check_ko test15-a Names test15-a@     # test15-a@.scope is the symlink target.
+                                          # Make sure it is completely ignored.
+
+    rm /test15-a@.scope
+    clear_units test15-{a,b}.service
+}
+
+testcase_template_alias() {
+    echo "Testing instance alias..."
+    echo "*** forward"
+
+    create_service test15-a@
+    ln -s test15-a@inst.service /etc/systemd/system/test15-b@inst.service  # alias
+
+    check_ok test15-a@inst Names test15-a@inst.service
+    check_ok test15-a@inst Names test15-b@inst.service
+
+    check_ok test15-a@other Names test15-a@other.service
+    check_ko test15-a@other Names test15-b@other.service
+
+    echo "*** reverse"
+
+    systemctl daemon-reload
+
+    check_ok test15-b@inst Names test15-a@inst.service
+    check_ok test15-b@inst Names test15-b@inst.service
+
+    check_ko test15-b@other Names test15-a@other.service
+    check_ok test15-b@other Names test15-b@other.service
+
+    clear_units test15-{a,b}@.service
+}
+
+testcase_hierarchical_service_dropins() {
+    echo "Testing hierarchical service dropins..."
+    echo "*** test service.d/ top level drop-in"
+    create_services a-b-c
+    check_ko a-b-c ExecCondition "echo service.d"
+    check_ko a-b-c ExecCondition "echo a-.service.d"
+    check_ko a-b-c ExecCondition "echo a-b-.service.d"
+    check_ko a-b-c ExecCondition "echo a-b-c.service.d"
+
+    for dropin in service.d a-.service.d a-b-.service.d a-b-c.service.d; do
+        mkdir -p "/run/systemd/system/$dropin"
+        cat >"/run/systemd/system/$dropin/override.conf" <<EOF
+[Service]
+ExecCondition=echo $dropin
+EOF
+        systemctl daemon-reload
+        check_ok a-b-c ExecCondition "echo $dropin"
+
+        # Check that we can start a transient service in presence of the drop-ins
+        systemd-run -u a-b-c2.service -p Description='sleepy' sleep infinity
+
+        # The transient setting replaces the default
+        check_ok a-b-c2.service Description "sleepy"
+
+        # The override takes precedence for ExecCondition
+        # (except the last iteration when it only applies to the other service)
+        if [ "$dropin" != "a-b-c.service.d" ]; then
+            check_ok a-b-c2.service ExecCondition "echo $dropin"
+        fi
+
+        # Check that things are the same after a reload
+        systemctl daemon-reload
+        check_ok a-b-c2.service Description "sleepy"
+        if [ "$dropin" != "a-b-c.service.d" ]; then
+            check_ok a-b-c2.service ExecCondition "echo $dropin"
+        fi
+
+        systemctl stop a-b-c2.service
+    done
+    for dropin in service.d a-.service.d a-b-.service.d a-b-c.service.d; do
+        rm -rf "/run/systemd/system/$dropin"
+    done
+
+    clear_units a-b-c.service
+}
+
+testcase_hierarchical_slice_dropins() {
+    echo "Testing hierarchical slice dropins..."
+    echo "*** test slice.d/ top level drop-in"
+    # Slice units don't even need a fragment, so we test the defaults here
+    check_ok a-b-c.slice Description "Slice /a/b/c"
+    check_ok a-b-c.slice MemoryMax "infinity"
+
+    # Test drop-ins
+    for dropin in slice.d a-.slice.d a-b-.slice.d a-b-c.slice.d; do
+        mkdir -p "/run/systemd/system/$dropin"
+        cat >"/run/systemd/system/$dropin/override.conf" <<EOF
+[Slice]
+MemoryMax=1000000000
+EOF
+        systemctl daemon-reload
+        check_ok a-b-c.slice MemoryMax "1000000000"
+
+        busctl call \
+               org.freedesktop.systemd1 \
+               /org/freedesktop/systemd1 \
+               org.freedesktop.systemd1.Manager \
+               StartTransientUnit 'ssa(sv)a(sa(sv))' \
+               'a-b-c.slice' 'replace' \
+               2 \
+               'Description' s 'slice too' \
+               'MemoryMax' t 1000000002 \
+               0
+
+        # The override takes precedence for MemoryMax
+        check_ok a-b-c.slice MemoryMax "1000000000"
+        # The transient setting replaces the default
+        check_ok a-b-c.slice Description "slice too"
+
+        # Check that things are the same after a reload
+        systemctl daemon-reload
+        check_ok a-b-c.slice MemoryMax "1000000000"
+        check_ok a-b-c.slice Description "slice too"
+
+        busctl call \
+               org.freedesktop.systemd1 \
+               /org/freedesktop/systemd1 \
+               org.freedesktop.systemd1.Manager \
+               StopUnit 'ss' \
+               'a-b-c.slice' 'replace'
+
+        rm -f "/run/systemd/system/$dropin/override.conf"
+    done
+
+    # Test unit with a fragment
+    cat >/run/systemd/system/a-b-c.slice <<EOF
+[Slice]
+MemoryMax=1000000001
+EOF
+    systemctl daemon-reload
+    check_ok a-b-c.slice MemoryMax "1000000001"
+
+    clear_units a-b-c.slice
+}
+
+testcase_transient_service_dropins() {
+    echo "Testing dropins for a transient service..."
+    echo "*** test transient service drop-ins"
+
+    mkdir -p /etc/systemd/system/service.d
+    mkdir -p /etc/systemd/system/a-.service.d
+    mkdir -p /etc/systemd/system/a-b-.service.d
+    mkdir -p /etc/systemd/system/a-b-c.service.d
+
+    echo -e '[Service]\nStandardInputText=aaa' >/etc/systemd/system/service.d/drop1.conf
+    echo -e '[Service]\nStandardInputText=bbb' >/etc/systemd/system/a-.service.d/drop2.conf
+    echo -e '[Service]\nStandardInputText=ccc' >/etc/systemd/system/a-b-.service.d/drop3.conf
+    echo -e '[Service]\nStandardInputText=ddd' >/etc/systemd/system/a-b-c.service.d/drop4.conf
+
+    # There's no fragment yet, so this fails
+    systemctl cat a-b-c.service && exit 1
+
+    # xxx → eHh4Cg==
+    systemd-run -u a-b-c.service -p StandardInputData=eHh4Cg== sleep infinity
+
+    data=$(systemctl show -P StandardInputData a-b-c.service)
+    # xxx\naaa\n\bbb\nccc\nddd\n → eHh4…
+    test "$data" = "eHh4CmFhYQpiYmIKY2NjCmRkZAo="
+
+    # Do a reload and check again
+    systemctl daemon-reload
+    data=$(systemctl show -P StandardInputData a-b-c.service)
+    test "$data" = "eHh4CmFhYQpiYmIKY2NjCmRkZAo="
+
+    clear_units a-b-c.service
+    rm /etc/systemd/system/service.d/drop1.conf \
+       /etc/systemd/system/a-.service.d/drop2.conf \
+       /etc/systemd/system/a-b-.service.d/drop3.conf
+}
+
+testcase_transient_slice_dropins() {
+    echo "Testing dropins for a transient slice..."
+    echo "*** test transient slice drop-ins"
+
+    # FIXME: implement reloading of individual units.
+    #
+    # The settings here are loaded twice. For most settings it doesn't matter,
+    # but Documentation is not deduplicated, so we current get repeated entried
+    # which is a bug.
+
+    mkdir -p /etc/systemd/system/slice.d
+    mkdir -p /etc/systemd/system/a-.slice.d
+    mkdir -p /etc/systemd/system/a-b-.slice.d
+    mkdir -p /etc/systemd/system/a-b-c.slice.d
+
+    echo -e '[Unit]\nDocumentation=man:drop1' >/etc/systemd/system/slice.d/drop1.conf
+    echo -e '[Unit]\nDocumentation=man:drop2' >/etc/systemd/system/a-.slice.d/drop2.conf
+    echo -e '[Unit]\nDocumentation=man:drop3' >/etc/systemd/system/a-b-.slice.d/drop3.conf
+    echo -e '[Unit]\nDocumentation=man:drop4' >/etc/systemd/system/a-b-c.slice.d/drop4.conf
+
+    # Invoke daemon-reload to make sure that the call below doesn't fail
+    systemctl daemon-reload
+
+    # No fragment is required, so this works
+    systemctl cat a-b-c.slice
+
+    busctl call \
+           org.freedesktop.systemd1 \
+           /org/freedesktop/systemd1 \
+           org.freedesktop.systemd1.Manager \
+           StartTransientUnit 'ssa(sv)a(sa(sv))' \
+           'a-b-c.slice' 'replace' \
+           1 \
+           'Documentation' as 1 'man:drop5' \
+           0
+
+    data=$(systemctl show -P Documentation a-b-c.slice)
+    test "$data" = "man:drop1 man:drop2 man:drop3 man:drop4 man:drop5 man:drop1 man:drop2 man:drop3 man:drop4"
+
+    # Do a reload and check again
+    systemctl daemon-reload
+    data=$(systemctl show -P Documentation a-b-c.slice)
+    test "$data" = "man:drop5 man:drop1 man:drop2 man:drop3 man:drop4"
+
+    clear_units a-b-c.slice
+    rm /etc/systemd/system/slice.d/drop1.conf \
+       /etc/systemd/system/a-.slice.d/drop2.conf \
+       /etc/systemd/system/a-b-.slice.d/drop3.conf
+}
+
+testcase_template_dropins() {
+    echo "Testing template dropins..."
+
+    create_services foo bar@ yup@
+
+    # Declare some deps to check if the body was loaded
+    cat >>/etc/systemd/system/bar@.service <<EOF
+[Unit]
+After=bar-template-after.device
+EOF
+
+    cat >>/etc/systemd/system/yup@.service <<EOF
+[Unit]
+After=yup-template-after.device
+EOF
+
+    ln -s /etc/systemd/system/bar@.service /etc/systemd/system/foo.service.wants/bar@1.service
+    check_ok foo Wants bar@1.service
+
+    echo "*** test bar-alias@.service→bar@.service, but instance symlinks point to yup@.service ***"
+    ln -s bar@.service  /etc/systemd/system/bar-alias@.service
+    ln -s bar@1.service /etc/systemd/system/bar-alias@1.service
+    ln -s yup@.service  /etc/systemd/system/bar-alias@2.service
+    ln -s yup@3.service /etc/systemd/system/bar-alias@3.service
+
+    # create some dropin deps
+    mkdir -p /etc/systemd/system/bar@{,0,1,2,3}.service.requires/
+    mkdir -p /etc/systemd/system/yup@{,0,1,2,3}.service.requires/
+    mkdir -p /etc/systemd/system/bar-alias@{,0,1,2,3}.service.requires/
+
+    ln -s ../bar-template-requires.device /etc/systemd/system/bar@.service.requires/
+    ln -s ../bar-0-requires.device /etc/systemd/system/bar@0.service.requires/
+    ln -s ../bar-1-requires.device /etc/systemd/system/bar@1.service.requires/
+    ln -s ../bar-2-requires.device /etc/systemd/system/bar@2.service.requires/
+    ln -s ../bar-3-requires.device /etc/systemd/system/bar@3.service.requires/
+
+    ln -s ../yup-template-requires.device /etc/systemd/system/yup@.service.requires/
+    ln -s ../yup-0-requires.device /etc/systemd/system/yup@0.service.requires/
+    ln -s ../yup-1-requires.device /etc/systemd/system/yup@1.service.requires/
+    ln -s ../yup-2-requires.device /etc/systemd/system/yup@2.service.requires/
+    ln -s ../yup-3-requires.device /etc/systemd/system/yup@3.service.requires/
+
+    ln -s ../bar-alias-template-requires.device /etc/systemd/system/bar-alias@.service.requires/
+    ln -s ../bar-alias-0-requires.device /etc/systemd/system/bar-alias@0.service.requires/
+    ln -s ../bar-alias-1-requires.device /etc/systemd/system/bar-alias@1.service.requires/
+    ln -s ../bar-alias-2-requires.device /etc/systemd/system/bar-alias@2.service.requires/
+    ln -s ../bar-alias-3-requires.device /etc/systemd/system/bar-alias@3.service.requires/
+
+    systemctl daemon-reload
+
+    echo '*** bar@0 is aliased by bar-alias@0 ***'
+    systemctl show -p Names,Requires bar@0
+    systemctl show -p Names,Requires bar-alias@0
+    check_ok bar@0 Names bar@0
+    check_ok bar@0 Names bar-alias@0
+
+    check_ok bar@0 After bar-template-after.device
+
+    check_ok bar@0 Requires bar-0-requires.device
+    check_ok bar@0 Requires bar-alias-0-requires.device
+    check_ok bar@0 Requires bar-template-requires.device
+    check_ok bar@0 Requires bar-alias-template-requires.device
+    check_ko bar@0 Requires yup-template-requires.device
+
+    check_ok bar-alias@0 After bar-template-after.device
+
+    check_ok bar-alias@0 Requires bar-0-requires.device
+    check_ok bar-alias@0 Requires bar-alias-0-requires.device
+    check_ok bar-alias@0 Requires bar-template-requires.device
+    check_ok bar-alias@0 Requires bar-alias-template-requires.device
+    check_ko bar-alias@0 Requires yup-template-requires.device
+    check_ko bar-alias@0 Requires yup-0-requires.device
+
+    echo '*** bar@1 is aliased by bar-alias@1 ***'
+    systemctl show -p Names,Requires bar@1
+    systemctl show -p Names,Requires bar-alias@1
+    check_ok bar@1 Names bar@1
+    check_ok bar@1 Names bar-alias@1
+
+    check_ok bar@1 After bar-template-after.device
+
+    check_ok bar@1 Requires bar-1-requires.device
+    check_ok bar@1 Requires bar-alias-1-requires.device
+    check_ok bar@1 Requires bar-template-requires.device
+    # See https://github.com/systemd/systemd/pull/13119#discussion_r308145418
+    check_ok bar@1 Requires bar-alias-template-requires.device
+    check_ko bar@1 Requires yup-template-requires.device
+    check_ko bar@1 Requires yup-1-requires.device
+
+    check_ok bar-alias@1 After bar-template-after.device
+
+    check_ok bar-alias@1 Requires bar-1-requires.device
+    check_ok bar-alias@1 Requires bar-alias-1-requires.device
+    check_ok bar-alias@1 Requires bar-template-requires.device
+    check_ok bar-alias@1 Requires bar-alias-template-requires.device
+    check_ko bar-alias@1 Requires yup-template-requires.device
+    check_ko bar-alias@1 Requires yup-1-requires.device
+
+    echo '*** bar-alias@2 aliases yup@2, bar@2 is independent ***'
+    systemctl show -p Names,Requires bar@2
+    systemctl show -p Names,Requires bar-alias@2
+    check_ok bar@2 Names bar@2
+    check_ko bar@2 Names bar-alias@2
+
+    check_ok bar@2 After bar-template-after.device
+
+    check_ok bar@2 Requires bar-2-requires.device
+    check_ko bar@2 Requires bar-alias-2-requires.device
+    check_ok bar@2 Requires bar-template-requires.device
+    check_ko bar@2 Requires bar-alias-template-requires.device
+    check_ko bar@2 Requires yup-template-requires.device
+    check_ko bar@2 Requires yup-2-requires.device
+
+    check_ko bar-alias@2 After bar-template-after.device
+
+    check_ko bar-alias@2 Requires bar-2-requires.device
+    check_ok bar-alias@2 Requires bar-alias-2-requires.device
+    check_ko bar-alias@2 Requires bar-template-requires.device
+    check_ok bar-alias@2 Requires bar-alias-template-requires.device
+    check_ok bar-alias@2 Requires yup-template-requires.device
+    check_ok bar-alias@2 Requires yup-2-requires.device
+
+    echo '*** bar-alias@3 aliases yup@3, bar@3 is independent ***'
+    systemctl show -p Names,Requires bar@3
+    systemctl show -p Names,Requires bar-alias@3
+    check_ok bar@3 Names bar@3
+    check_ko bar@3 Names bar-alias@3
+
+    check_ok bar@3 After bar-template-after.device
+
+    check_ok bar@3 Requires bar-3-requires.device
+    check_ko bar@3 Requires bar-alias-3-requires.device
+    check_ok bar@3 Requires bar-template-requires.device
+    check_ko bar@3 Requires bar-alias-template-requires.device
+    check_ko bar@3 Requires yup-template-requires.device
+    check_ko bar@3 Requires yup-3-requires.device
+
+    check_ko bar-alias@3 After bar-template-after.device
+
+    check_ko bar-alias@3 Requires bar-3-requires.device
+    check_ok bar-alias@3 Requires bar-alias-3-requires.device
+    check_ko bar-alias@3 Requires bar-template-requires.device
+    check_ok bar-alias@3 Requires bar-alias-template-requires.device
+    check_ok bar-alias@3 Requires yup-template-requires.device
+    check_ok bar-alias@3 Requires yup-3-requires.device
+
+    clear_units foo.service {bar,yup,bar-alias}@{,1,2,3}.service
+}
+
+testcase_alias_dropins() {
+    echo "Testing alias dropins..."
+
+    echo "*** test a wants b1 alias of b"
+    create_services test15-a test15-b
+    ln -sf test15-b.service /etc/systemd/system/test15-b1.service
+    ln -sf ../test15-b1.service /etc/systemd/system/test15-a.service.wants/
+    check_ok test15-a Wants test15-b.service
+    systemctl start test15-a
+    systemctl --quiet is-active test15-b
+    systemctl stop test15-a test15-b
+    rm /etc/systemd/system/test15-b1.service
+    clear_units test15-{a,b}.service
+
+    # Check that dependencies don't vary.
+    echo "*** test 2"
+    create_services test15-a test15-x test15-y
+    mkdir -p /etc/systemd/system/test15-a1.service.wants/
+    ln -sf test15-a.service /etc/systemd/system/test15-a1.service
+    ln -sf ../test15-x.service /etc/systemd/system/test15-a.service.wants/
+    ln -sf ../test15-y.service /etc/systemd/system/test15-a1.service.wants/
+    check_ok test15-a1 Wants test15-x.service # see [1]
+    check_ok test15-a1 Wants test15-y.service
+    systemctl start test15-a
+    check_ok test15-a1 Wants test15-x.service # see [2]
+    check_ok test15-a1 Wants test15-y.service
+    systemctl stop test15-a test15-x test15-y
+    rm /etc/systemd/system/test15-a1.service
+
+    clear_units test15-{a,x,y}.service
+}
+
+testcase_masked_dropins() {
+    echo "Testing masked dropins..."
+
+    create_services test15-a test15-b
+
+    # 'b' is masked for both deps
+    echo "*** test a wants,requires b is masked"
+    ln -sf /dev/null /etc/systemd/system/test15-a.service.wants/test15-b.service
+    ln -sf /dev/null /etc/systemd/system/test15-a.service.requires/test15-b.service
+    check_ko test15-a Wants test15-b.service
+    check_ko test15-a Requires test15-b.service
+
+    # 'a' wants 'b' and 'b' is masked at a lower level
+    echo "*** test a wants b, mask override"
+    ln -sf ../test15-b.service /etc/systemd/system/test15-a.service.wants/test15-b.service
+    ln -sf /dev/null /usr/lib/systemd/system/test15-a.service.wants/test15-b.service
+    check_ok test15-a Wants test15-b.service
+
+    # 'a' wants 'b' and 'b' is masked at a higher level
+    echo "*** test a wants b, mask"
+    ln -sf /dev/null /etc/systemd/system/test15-a.service.wants/test15-b.service
+    ln -sf ../test15-b.service /usr/lib/systemd/system/test15-a.service.wants/test15-b.service
+    check_ko test15-a Wants test15-b.service
+
+    # 'a' is masked but has an override config file
+    echo "*** test a is masked but has an override"
+    create_services test15-a test15-b
+    ln -sf /dev/null /etc/systemd/system/test15-a.service
+    cat >/usr/lib/systemd/system/test15-a.service.d/override.conf <<EOF
+[Unit]
+After=test15-b.service
+EOF
+    check_ok test15-a UnitFileState masked
+
+    # 'b1' is an alias for 'b': masking 'b' dep should not influence 'b1' dep
+    echo "*** test a wants b, b1, and one is masked"
+    create_services test15-a test15-b
+    ln -sf test15-b.service /etc/systemd/system/test15-b1.service
+    ln -sf /dev/null /etc/systemd/system/test15-a.service.wants/test15-b.service
+    ln -sf ../test15-b1.service /usr/lib/systemd/system/test15-a.service.wants/test15-b1.service
+    systemctl cat test15-a
+    systemctl show -p Wants,Requires test15-a
+    systemctl cat test15-b1
+    systemctl show -p Wants,Requires test15-b1
+    check_ok test15-a Wants test15-b.service
+    check_ko test15-a Wants test15-b1.service # the alias does not show up in the list of units
+    rm /etc/systemd/system/test15-b1.service
+
+    # 'b1' is an alias for 'b': masking 'b1' should not influence 'b' dep
+    echo "*** test a wants b, alias dep is masked"
+    create_services test15-a test15-b
+    ln -sf test15-b.service /etc/systemd/system/test15-b1.service
+    ln -sf /dev/null /etc/systemd/system/test15-a.service.wants/test15-b1.service
+    ln -sf ../test15-b.service /usr/lib/systemd/system/test15-a.service.wants/test15-b.service
+    check_ok test15-a Wants test15-b.service
+    check_ko test15-a Wants test15-b1.service # the alias does not show up in the list of units
+    rm /etc/systemd/system/test15-b1.service
+
+    # 'a' has Wants=b.service but also has a masking
+    # dropin 'b': 'b' should still be pulled in.
+    echo "*** test a wants b both ways"
+    create_services test15-a test15-b
+    ln -sf /dev/null /etc/systemd/system/test15-a.service.wants/test15-b.service
+    cat >/usr/lib/systemd/system/test15-a.service.d/wants-b.conf <<EOF
+[Unit]
+Wants=test15-b.service
+EOF
+    check_ok test15-a Wants test15-b.service
+
+    # mask a dropin that points to an nonexistent unit.
+    echo "*** test a wants nonexistent is masked"
+    create_services test15-a
+    ln -sf /dev/null /etc/systemd/system/test15-a.service.requires/nonexistent.service
+    ln -sf ../nonexistent.service /usr/lib/systemd/system/test15-a.service.requires/
+    check_ko test15-a Requires nonexistent.service
+
+    # 'b' is already loaded when 'c' pulls it in via a dropin but 'b' is
+    # masked at a higher level.
+    echo "*** test a wants b is masked"
+    create_services test15-a test15-b test15-c
+    ln -sf ../test15-b.service /etc/systemd/system/test15-a.service.requires/
+    ln -sf ../test15-b.service /run/systemd/system/test15-c.service.requires/
+    ln -sf /dev/null /etc/systemd/system/test15-c.service.requires/test15-b.service
+    systemctl start test15-a
+    check_ko test15-c Requires test15-b.service
+    systemctl stop test15-a test15-b
+
+    # 'b' is already loaded when 'c' pulls it in via a dropin but 'b' is
+    # masked at a lower level.
+    echo "*** test a requires b is masked"
+    create_services test15-a test15-b test15-c
+    ln -sf ../test15-b.service /etc/systemd/system/test15-a.service.requires/
+    ln -sf ../test15-b.service /etc/systemd/system/test15-c.service.requires/
+    ln -sf /dev/null /run/systemd/system/test15-c.service.requires/test15-b.service
+    systemctl start test15-a
+    check_ok test15-c Requires test15-b.service
+    systemctl stop test15-a test15-b
+
+    # 'a' requires 2 aliases of 'b' and one of them is a mask.
+    echo "*** test a requires alias of b, other alias masked"
+    create_services test15-a test15-b
+    ln -sf test15-b.service /etc/systemd/system/test15-b1.service
+    ln -sf test15-b.service /etc/systemd/system/test15-b2.service
+    ln -sf /dev/null /etc/systemd/system/test15-a.service.requires/test15-b1.service
+    ln -sf ../test15-b1.service /run/systemd/system/test15-a.service.requires/
+    ln -sf ../test15-b2.service /usr/lib/systemd/system/test15-a.service.requires/
+    check_ok test15-a Requires test15-b
+
+    # Same as above but now 'b' is masked.
+    echo "*** test a requires alias of b, b dep masked"
+    create_services test15-a test15-b
+    ln -sf test15-b.service /etc/systemd/system/test15-b1.service
+    ln -sf test15-b.service /etc/systemd/system/test15-b2.service
+    ln -sf ../test15-b1.service /run/systemd/system/test15-a.service.requires/
+    ln -sf ../test15-b2.service /usr/lib/systemd/system/test15-a.service.requires/
+    ln -sf /dev/null /etc/systemd/system/test15-a.service.requires/test15-b.service
+    check_ok test15-a Requires test15-b
+
+    clear_units test15-{a,b}.service
+}
+
+testcase_invalid_dropins() {
+    echo "Testing invalid dropins..."
+    # Assertion failed on earlier versions, command exits unsuccessfully on later versions
+    systemctl cat nonexistent@.service || true
+    create_services a
+    systemctl daemon-reload
+    # Assertion failed on earlier versions, command exits unsuccessfully on later versions
+    systemctl cat a@.service || true
+    systemctl stop a
+    clear_units a.service
+    return 0
+}
+
+testcase_symlink_dropin_directory() {
+    # For issue #21920.
+    echo "Testing symlink drop-in directory..."
+    create_services test15-a
+    rmdir /{etc,run,usr/lib}/systemd/system/test15-a.service.d
+    mkdir -p /tmp/testsuite-15-test15-a-dropin-directory
+    ln -s /tmp/testsuite-15-test15-a-dropin-directory /etc/systemd/system/test15-a.service.d
+    cat >/tmp/testsuite-15-test15-a-dropin-directory/override.conf <<EOF
+[Unit]
+Description=hogehoge
+EOF
+    ln -s /tmp/testsuite-15-test15-a-dropin-directory-nonexistent /run/systemd/system/test15-a.service.d
+    touch /tmp/testsuite-15-test15-a-dropin-directory-regular
+    ln -s /tmp/testsuite-15-test15-a-dropin-directory-regular /usr/lib/systemd/system/test15-a.service.d
+    check_ok test15-a Description hogehoge
+
+    clear_units test15-a.service
+}
+
+run_testcases
+
+touch /testok