core: make nm_utils_cmp_connection_by_autoconnect_priority() more robust

Check for NULL and unexpected missing NMSettingConnection.
Be more forgiving and accept whatever is there when comparing
@a with @b.

1 files changed, 43 insertions, 13 deletions

diff --git a/src/nm-core-utils.c b/src/nm-core-utils.c
index 29c26ba817..143fdfe8b9 100644
--- a/src/nm-core-utils.c
+++ b/src/nm-core-utils.c
@@ -1975,27 +1975,57 @@ nm_utils_read_resolv_conf_dns_options (const char *rc_contents)
 	return options;
 }
 
+/*****************************************************************************/
+
+/**
+ * nm_utils_cmp_connection_by_autoconnect_priority:
+ * @a:
+ * @b:
+ *
+ * compare connections @a and @b for their autoconnect property
+ * (with sorting the connection that has autoconnect enabled before
+ * the other)
+ * If they both have autoconnect enabled, sort them depending on their
+ * autoconnect-priority (with the higher priority first).
+ *
+ * If their autoconnect/autoconnect-priority is the same, 0 is returned.
+ * That is, they compare equal.
+ *
+ * Returns: -1, 0, or 1
+ */
 int
 nm_utils_cmp_connection_by_autoconnect_priority (NMConnection *a, NMConnection *b)
 {
-	NMSettingConnection *a_s_con, *b_s_con;
-	gboolean a_ac, b_ac;
-	gint a_ap, b_ap;
+	NMSettingConnection *a_s_con;
+	NMSettingConnection *b_s_con;
+	int a_ap, b_ap;
+	gboolean can_autoconnect;
+
+	if (a == b)
+		return 0;
+	if (!a)
+		return 1;
+	if (!b)
+		return -1;
 
 	a_s_con = nm_connection_get_setting_connection (a);
 	b_s_con = nm_connection_get_setting_connection (b);
 
-	a_ac = !!nm_setting_connection_get_autoconnect (a_s_con);
-	b_ac = !!nm_setting_connection_get_autoconnect (b_s_con);
-	if (a_ac != b_ac)
-		return ((int) b_ac) - ((int) a_ac);
-	if (!a_ac)
-		return 0;
+	if (!a_s_con)
+		return !b_s_con ? 0 : 1;
+	if (!b_s_con)
+		return -1;
+
+	can_autoconnect = !!nm_setting_connection_get_autoconnect (a_s_con);
+	if (can_autoconnect != (!!nm_setting_connection_get_autoconnect (b_s_con)))
+		return can_autoconnect ? -1 : 1;
 
-	a_ap = nm_setting_connection_get_autoconnect_priority (a_s_con);
-	b_ap = nm_setting_connection_get_autoconnect_priority (b_s_con);
-	if (a_ap != b_ap)
-		return (a_ap > b_ap) ? -1 : 1;
+	if (can_autoconnect) {
+		a_ap = nm_setting_connection_get_autoconnect_priority (a_s_con);
+		b_ap = nm_setting_connection_get_autoconnect_priority (b_s_con);
+		if (a_ap != b_ap)
+			return (a_ap > b_ap) ? -1 : 1;
+	}
 
 	return 0;
 }