ci(TEST-62-SKIPCPIO): add simple skipcpio test

Signed-off-by: David Disseldorp <ddiss@suse.de>

test/TEST-62-SKIPCPIO/Makefile

@@ -0,0 +1 @@
+-include ../Makefile.testdir

test/TEST-62-SKIPCPIO/test.sh

@@ -0,0 +1,75 @@
+#!/bin/bash
+# This file is part of dracut.
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# shellcheck disable=SC2034
+TEST_DESCRIPTION="test skipcpio"
+
+test_check() {
+    which cpio dd truncate find sort diff &> /dev/null
+}
+
+skipcpio_simple() {
+    mkdir -p "$CPIO_TESTDIR/skipcpio_simple/first_archive"
+    pushd "$CPIO_TESTDIR/skipcpio_simple/first_archive"
+
+    for ((i = 0; i < 3; i++)); do
+        echo "first archive file $i" >> ./"$i"
+    done
+    find . -print0 | sort -z \
+        | cpio -o --null -H newc --file "$CPIO_TESTDIR/skipcpio_simple.cpio"
+    popd
+
+    mkdir -p "$CPIO_TESTDIR/skipcpio_simple/second_archive"
+    pushd "$CPIO_TESTDIR/skipcpio_simple/second_archive"
+
+    for ((i = 10; i < 13; i++)); do
+        echo "second archive file $i" >> ./"$i"
+    done
+
+    find . -print0 | sort -z \
+        | cpio -o --null -H newc >> "$CPIO_TESTDIR/skipcpio_simple.cpio"
+    popd
+
+    cpio -i --list < "$CPIO_TESTDIR/skipcpio_simple.cpio" \
+        > "$CPIO_TESTDIR/skipcpio_simple.list"
+    cat << EOF | diff - "$CPIO_TESTDIR/skipcpio_simple.list"
+.
+0
+1
+2
+EOF
+
+    "$basedir"/src/skipcpio/skipcpio "$CPIO_TESTDIR/skipcpio_simple.cpio" \
+        | cpio -i --list > "$CPIO_TESTDIR/skipcpio_simple.list"
+    cat << EOF | diff - "$CPIO_TESTDIR/skipcpio_simple.list"
+.
+10
+11
+12
+EOF
+}
+
+test_run() {
+    set -x
+    set -e
+
+    skipcpio_simple
+
+    return 0
+}
+
+test_setup() {
+    CPIO_TESTDIR=$(mktemp --directory -p "$TESTDIR" cpio-test.XXXXXXXXXX) \
+        || return 1
+    export CPIO_TESTDIR
+    return 0
+}
+
+test_cleanup() {
+    [ -d "$CPIO_TESTDIR" ] && rm -rf "$CPIO_TESTDIR"
+    return 0
+}
+
+# shellcheck disable=SC1090
+. "$testdir"/test-functions