diff --git a/test/units/testsuite-04.sh b/test/units/testsuite-04.sh
index 3c4c8afd53..6ed41f24ea 100755
--- a/test/units/testsuite-04.sh
+++ b/test/units/testsuite-04.sh
@@ -154,8 +154,12 @@ sleep 3
 [[ ! -f "/tmp/i-lose-my-logs" ]]
 systemctl stop forever-print-hola
 
+set +o pipefail
 # https://github.com/systemd/systemd/issues/15528
-journalctl --follow --file=/var/log/journal/*/* | head -n1 || [[ $? -eq 1 ]]
+journalctl --follow --file=/var/log/journal/*/* | head -n1 | grep .
+# https://github.com/systemd/systemd/issues/24565
+journalctl --follow --merge | head -n1 | grep .
+set -o pipefail
 
 add_logs_filtering_override() {
     local unit="${1:?}"
diff --git a/test/units/testsuite-07.mount-invalid-chars.sh b/test/units/testsuite-07.mount-invalid-chars.sh
new file mode 100755
index 0000000000..617ea697c8
--- /dev/null
+++ b/test/units/testsuite-07.mount-invalid-chars.sh
@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -eux
+set -o pipefail
+
+# Don't send invalid characters over dbus if a mount contains them
+
+at_exit() {
+    mountpoint -q /proc/1/mountinfo && umount /proc/1/mountinfo
+    [[ -e /tmp/fstab.bak ]] && mv -f /tmp/fstab /etc/fstab
+    rm -f /run/systemd/system/foo-*.mount
+    systemctl daemon-reload
+}
+
+trap at_exit EXIT
+
+# Check invalid characters directly in /proc/mountinfo
+#
+# This is a bit tricky (and hacky), since we have to temporarily replace
+# PID 1's /proc/mountinfo, but we have to keep the original mounts intact,
+# otherwise systemd would unmount them on reload
+TMP_MOUNTINFO="$(mktemp)"
+
+cp /proc/1/mountinfo "$TMP_MOUNTINFO"
+# Add a mount entry with a "Unicode non-character" in it
+echo -ne '69 1 252:2 / /foo/mountinfo rw,relatime shared:1 - cifs //foo\ufffebar rw,seclabel\n' >>"$TMP_MOUNTINFO"
+mount --bind "$TMP_MOUNTINFO" /proc/1/mountinfo
+systemctl daemon-reload
+# On affected versions this would throw an error:
+#   Failed to get properties: Bad message
+systemctl status foo-mountinfo.mount
+
+umount /proc/1/mountinfo
+systemctl daemon-reload
+rm -f "$TMP_MOUNTINFO"
+
+# Check invalid characters in a mount unit
+#
+# systemd already handles this and refuses to load the invalid string, e.g.:
+#   foo-fstab.mount:9: String is not UTF-8 clean, ignoring assignment: What=//localhost/foo���bar
+#
+# a) Unit generated from /etc/fstab
+[[ -e /etc/fstab ]] && cp -f /etc/fstab /tmp/fstab.bak
+
+echo -ne '//localhost/foo\ufffebar  /foo/fstab  cifs defaults 0 0\n' >/etc/fstab
+systemctl daemon-reload
+[[ "$(systemctl show -P UnitFileState foo-fstab.mount)" == bad ]]
+
+# b) Unit generated from /etc/fstab (but the invalid character is in options)
+echo -ne '//localhost/foobar  /foo/fstab/opt  cifs nosuid,a\ufffeb,noexec 0 0\n' >/etc/fstab
+systemctl daemon-reload
+[[ "$(systemctl show -P UnitFileState foo-fstab-opt.mount)" == bad ]]
+rm -f /etc/fstab
+
+[[ -e /tmp/fstab.bak ]] && mv -f /tmp/fstab /etc/fstab
+systemctl daemon-reload
+
+# c) Mount unit
+mkdir -p /run/systemd/system
+echo -ne '[Mount]\nWhat=//localhost/foo\ufffebar\nWhere=/foo/unit\nType=cifs\nOptions=noexec\n' >/run/systemd/system/foo-unit.mount
+systemctl daemon-reload
+[[ "$(systemctl show -P UnitFileState foo-unit.mount)" == bad ]]
+rm -f /run/systemd/system/foo-unit.mount
+
+# d) Mount unit (but the invalid character is in Options=)
+mkdir -p /run/systemd/system
+echo -ne '[Mount]\nWhat=//localhost/foobar\nWhere=/foo/unit/opt\nType=cifs\nOptions=noexec,a\ufffeb,nosuid\n' >/run/systemd/system/foo-unit-opt.mount
+systemctl daemon-reload
+[[ "$(systemctl show -P UnitFileState foo-unit-opt.mount)" == bad ]]
+rm -f /run/systemd/system/foo-unit-opt.mount
diff --git a/test/units/testsuite-13.nspawn-oci.sh b/test/units/testsuite-13.nspawn-oci.sh
index 6329d25f3b..8fa0bc4290 100755
--- a/test/units/testsuite-13.nspawn-oci.sh
+++ b/test/units/testsuite-13.nspawn-oci.sh
@@ -76,6 +76,7 @@ cat >"$OCI/config.json" <<EOF
             "type" : "tmpfs",
             "source" : "tmpfs"
         },
+        ${COVERAGE_BUILD_DIR:+"{ \"destination\" : \"$COVERAGE_BUILD_DIR\" },"}
         {
             "destination" : "/var",
             "type" : "none",
diff --git a/test/units/testsuite-13.nspawn.sh b/test/units/testsuite-13.nspawn.sh
index c01361999a..0cc96424e6 100755
--- a/test/units/testsuite-13.nspawn.sh
+++ b/test/units/testsuite-13.nspawn.sh
@@ -18,8 +18,13 @@
 #   - also a note - if /etc/systemd/nspawn/cont-name.nspawn exists, it takes
 #     precedence and /run/systemd/nspawn/cont-name.nspawn won't be read even
 #     if it exists
+#   - also a note 2 - --bind= overrides any Bind= from a config file
 #   - in some cases we don't create a test container using create_dummy_container(),
 #     so in that case an explicit call to coverage_create_nspawn_dropin() is needed
+#
+# However, even after jumping through all these hooks, there still might (and is)
+# some "incorrectly" missing coverage, especially in the window between spawning
+# the inner child process and bind-mounting the coverage $BUILD_DIR
 set -eux
 set -o pipefail
 
@@ -101,7 +106,6 @@ testcase_sanity() {
     systemd-nspawn --directory="$root" --ephemeral bash -xec 'touch /ephemeral'
     test ! -e "$root/ephemeral"
     (! systemd-nspawn --directory="$root" \
-                      --bind="${COVERAGE_BUILD_DIR:-$tmpdir}" \
                       --read-only \
                       bash -xec 'touch /nope')
     test ! -e "$root/nope"
@@ -122,7 +126,6 @@ testcase_sanity() {
     test ! -e "$root/usr/read-only"
     # volatile=state: rootfs is read-only, /var/ is tmpfs
     systemd-nspawn --directory="$root" \
-                   --bind="${COVERAGE_BUILD_DIR:-$tmpdir}" \
                    --volatile=state \
                    bash -xec 'test -e /usr/has-usr; mountpoint /var; touch /read-only && exit 1; touch /var/nope'
     test ! -e "$root/read-only"
@@ -206,13 +209,16 @@ EOF
     touch "$tmpdir/foo"
     # --bind=
     systemd-nspawn --directory="$root" \
+                   ${COVERAGE_BUILD_DIR:+--bind="$COVERAGE_BUILD_DIR"} \
                    --bind="$tmpdir:/foo" \
-                   bash -xec 'test -e /foo/foo; touch /foo/bar'
+                   --bind="$tmpdir:/also-foo:noidmap,norbind" \
+                   bash -xec 'test -e /foo/foo; touch /foo/bar; test -e /also-foo/bar'
     test -e "$tmpdir/bar"
     # --bind-ro=
     systemd-nspawn --directory="$root" \
                    --bind-ro="$tmpdir:/foo" \
-                   bash -xec 'test -e /foo/foo; touch /foo/baz && exit 1; true'
+                   --bind-ro="$tmpdir:/bar:noidmap,norbind" \
+                   bash -xec 'test -e /foo/foo; touch /foo/baz && exit 1; touch /bar && exit 1; true'
     # --inaccessible=
     systemd-nspawn --directory="$root" \
                    --inaccessible=/var \
@@ -247,6 +253,22 @@ EOF
     (! systemd-nspawn --network-veth --directory="$root" --port=icmp:80:8080 true)
     (! systemd-nspawn --network-veth --directory="$root" --port=tcp::8080 true)
     (! systemd-nspawn --network-veth --directory="$root" --port=8080: true)
+    # Exercise adding/removing ports from an interface
+    systemd-nspawn --directory="$root" \
+                   --network-veth \
+                   --port=6667 \
+                   --port=80:8080 \
+                   --port=udp:53 \
+                   --port=tcp:22:2222 \
+                   bash -xec 'ip addr add dev host0 10.0.0.10/24; ip a; ip addr del dev host0 10.0.0.10/24'
+
+    # --load-credential=, --set-credential=
+    echo "foo bar" >/tmp/cred.path
+    systemd-nspawn --directory="$root" \
+                   --load-credential=cred.path:/tmp/cred.path \
+                   --set-credential="cred.set:hello world" \
+                   bash -xec '[[ "$(</run/host/credentials/cred.path)" == "foo bar" ]]; [[ "$(</run/host/credentials/cred.set)" == "hello world" ]]'
+    rm -f /tmp/cred.path
 
     # Assorted tests
     systemd-nspawn --directory="$root" --suppress-sync=yes bash -xec 'echo hello'
diff --git a/test/units/testsuite-73.sh b/test/units/testsuite-73.sh
index 39992a844b..523acd8d06 100755
--- a/test/units/testsuite-73.sh
+++ b/test/units/testsuite-73.sh
@@ -51,7 +51,7 @@ restore_locale() {
     fi
 }
 
-test_locale() {
+testcase_locale() {
     local i output
 
     if [[ -f /etc/locale.conf ]]; then
@@ -222,7 +222,7 @@ wait_vconsole_setup() {
     return 1
 }
 
-test_vc_keymap() {
+testcase_vc_keymap() {
     local i output vc
 
     if [[ -z "$(localectl list-keymaps)" ]]; then
@@ -292,7 +292,7 @@ test_vc_keymap() {
     assert_in "VC Keymap: .unset." "$(localectl)"
 }
 
-test_x11_keymap() {
+testcase_x11_keymap() {
     local output
 
     if [[ -z "$(localectl list-x11-keymap-layouts)" ]]; then
@@ -431,7 +431,7 @@ XKBMODEL=pc105+inet"
     assert_not_in "X11 Options:" "$output"
 }
 
-test_convert() {
+testcase_convert() {
     if [[ -z "$(localectl list-keymaps)" ]]; then
         echo "No vconsole keymap installed, skipping test."
         return
@@ -552,7 +552,7 @@ test_convert() {
     assert_not_in "X11 Options:"   "$output"
 }
 
-test_validate() {
+testcase_validate() {
     if [[ -z "$(localectl list-keymaps)" ]]; then
         echo "No vconsole keymap installed, skipping test."
         return
@@ -648,6 +648,38 @@ EOF
     assert_in "XKBLAYOUT=us" "$output"
 }
 
+locale_gen_cleanup() {
+    # Some running apps might keep the mount point busy, hence the lazy unmount
+    mountpoint -q /usr/lib/locale && umount --lazy /usr/lib/locale
+    [[ -e /tmp/locale.gen.bak ]] && mv -f /tmp/locale.gen.bak /etc/locale.gen
+
+    return 0
+}
+
+# Issue: https://github.com/systemd/systemd/pull/27179
+testcase_locale_gen_leading_space() {
+    if ! command -v locale-gen >/dev/null; then
+        echo "No locale-gen support, skipping test."
+        return 0
+    fi
+
+    [[ -e /etc/locale.gen ]] && cp -f /etc/locale.gen /tmp/locale.gen.bak
+    trap locale_gen_cleanup RETURN
+    # Overmount the existing locale-gen database with an empty directory
+    # to force it to regenerate locales
+    mount -t tmpfs tmpfs /usr/lib/locale
+
+    {
+        echo -e "en_US.UTF-8 UTF-8"
+        echo -e " en_US.UTF-8 UTF-8"
+        echo -e "\ten_US.UTF-8 UTF-8"
+        echo -e " \t en_US.UTF-8 UTF-8 \t"
+    } >/etc/locale.gen
+
+    localectl set-locale de_DE.UTF-8
+    localectl set-locale en_US.UTF-8
+}
+
 : >/failed
 
 # Make sure the content of kbd-model-map is the one that the tests expect
@@ -656,11 +688,18 @@ EOF
 export SYSTEMD_KBD_MODEL_MAP=/usr/lib/systemd/tests/testdata/test-keymap-util/kbd-model-map
 
 enable_debug
-test_locale
-test_vc_keymap
-test_x11_keymap
-test_convert
-test_validate
+
+# Create a list of all functions prefixed with testcase_
+mapfile -t TESTCASES < <(declare -F | awk '$3 ~ /^testcase_/ {print $3;}')
+
+if [[ "${#TESTCASES[@]}" -eq 0 ]]; then
+    echo >&2 "No test cases found, this is most likely an error"
+    exit 1
+fi
+
+for testcase in "${TESTCASES[@]}"; do
+    "$testcase"
+done
 
 touch /testok
 rm /failed