1 files changed, 27 insertions, 0 deletions
diff --git a/lib/common/lists.c b/lib/common/lists.c
new file mode 100644
index 0000000..9cd88d7
--- /dev/null
+++ b/lib/common/lists.c
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2004-2022 the Pacemaker project contributors
+ *
+ * The version control history for this file may have further details.
+ *
+ * This source code is licensed under the GNU Lesser General Public License
+ * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
+ */
+
+#include <crm_internal.h>
+#include <crm/common/lists_internal.h>
+
+GList*
+pcmk__subtract_lists(GList *from, const GList *items, GCompareFunc cmp)
+{
+    GList *result = g_list_copy(from);
+
+    for (const GList *item = items; item != NULL; item = item->next) {
+        GList *match = g_list_find_custom(result, item->data, cmp);
+
+        if (match != NULL) {
+            result = g_list_remove(result, match->data);
+        }
+    }
+
+    return result;
+}