[PATCH 4/4] unit: Skip hwdb test when hwdb isn't available

Alpine includes a compatible libudev without implementing hwdb, so skip
the test on that platform.
---
 unit/test-hwdb.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/unit/test-hwdb.c b/unit/test-hwdb.c
index 1c4928f3f993..f45f3973d2b9 100644
--- a/unit/test-hwdb.c
+++ b/unit/test-hwdb.c
@@ -14,6 +14,8 @@
 
 #include <ell/ell.h>
 
+static struct l_hwdb *hwdb = NULL;
+
 struct hwdb_stats {
 	int aliases;
 	int entries;
@@ -56,11 +58,9 @@ static void check_entry(const char *modalias, struct l_hwdb_entry *entries,
 
 static void test_hwdb(const void *data)
 {
-	struct l_hwdb *hwdb;
 	struct hwdb_stats stats = { 0 };
 	bool result;
 
-	hwdb = l_hwdb_new_default();
 	assert(hwdb);
 
 	result = l_hwdb_foreach(hwdb, check_entry, &stats);
@@ -84,11 +84,18 @@ static void test_hwdb(const void *data)
 	l_hwdb_unref(hwdb);
 }
 
+static bool test_hwdb_precheck (const void *data)
+{
+	hwdb = l_hwdb_new_default();
+	return hwdb != NULL;
+}
+
 int main(int argc, char *argv[])
 {
 	l_test_init(&argc, &argv);
 
-	l_test_add("hwdb", test_hwdb, NULL);
+	l_test_add_func_precheck("hwdb",
+				test_hwdb, test_hwdb_precheck, 0);
 
 	return l_test_run();
 }
-- 
2.53.0