tests: Assert that byte-order is swapped on LE but not BE CPUs

Closes: #1392
Signed-off-by: Simon McVittie <smcv@collabora.com>

Closes: #1393
Approved by: cgwalters

tests/basic-test.sh

@@ -759,8 +759,20 @@ $OSTREE show --print-metadata-key=FOO test2 > test2-meta
 assert_file_has_content test2-meta "BAR"
 $OSTREE show --print-metadata-key=KITTENS test2 > test2-meta
 assert_file_has_content test2-meta "CUTE"
+
 $OSTREE show --print-metadata-key=SOMENUM test2 > test2-meta
-assert_file_has_content test2-meta "uint64 3026418949592973312"
+case "$("${test_builddir}/get-byte-order")" in
+    (4321)
+        assert_file_has_content test2-meta "uint64 42"
+        ;;
+    (1234)
+        assert_file_has_content test2-meta "uint64 3026418949592973312"
+        ;;
+    (*)
+        fatal "neither little-endian nor big-endian?"
+        ;;
+esac
+
 $OSTREE show -B --print-metadata-key=SOMENUM test2 > test2-meta
 assert_file_has_content test2-meta "uint64 42"
 $OSTREE show --print-detached-metadata-key=SIGNATURE test2 > test2-meta

tests/get-byte-order.c

@@ -0,0 +1,12 @@
+/* Helper for OSTree tests: return host byte order */
+
+#include "config.h"
+
+#include <glib.h>
+
+int
+main (void)
+{
+  g_print ("%d\n", G_BYTE_ORDER);
+  return 0;
+}