Addon dtbs leads to the dt_flags header field set to FDT_FLAG_ADDON
(0x1).

Add a specific test to check this value.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 tests/metadata_dtflags1.dtb.expect |  1 +
 tests/metadata_dtflags1.dts        | 11 +++++++++++
 tests/run_tests.sh                 |  6 ++++++
 3 files changed, 18 insertions(+)
 create mode 100644 tests/metadata_dtflags1.dtb.expect
 create mode 100644 tests/metadata_dtflags1.dts

diff --git a/tests/metadata_dtflags1.dtb.expect b/tests/metadata_dtflags1.dtb.expect
new file mode 100644
index 0000000..00f98f3
--- /dev/null
+++ b/tests/metadata_dtflags1.dtb.expect
@@ -0,0 +1 @@
+// dt_flags:		0x1
diff --git a/tests/metadata_dtflags1.dts b/tests/metadata_dtflags1.dts
new file mode 100644
index 0000000..d2b2295
--- /dev/null
+++ b/tests/metadata_dtflags1.dts
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
+/*
+ * Copyright (C) 2026 Bootlin
+ */
+
+/dts-v1/;
+/addon/;
+
+/ {
+	prop = <1>;
+};
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index 496fcb9..688d81d 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -1147,6 +1147,12 @@ metadata_tests() {
 	# Keep only lines containing 'dt_flags'
 	sed -i '/dt_flags/!d' metadata_dtflags0.dtb.out
 	base_run_test check_diff metadata_dtflags0.dtb.out "$SRCDIR/metadata_dtflags0.dtb.expect"
+
+	run_dtc_test -I dts -O dtb -o metadata_dtflags1.dtb "$SRCDIR/metadata_dtflags1.dts"
+	base_run_test wrap_fdtdump metadata_dtflags1.dtb metadata_dtflags1.dtb.out
+	# Keep only lines containing 'dt_flags'
+	sed -i '/dt_flags/!d' metadata_dtflags1.dtb.out
+	base_run_test check_diff metadata_dtflags1.dtb.out "$SRCDIR/metadata_dtflags1.dtb.expect"
 }
 
 pylibfdt_tests () {
-- 
2.52.0