Forgot in previous commit.

src/diff.h

@@ -64,4 +64,11 @@ gint rspamd_diff(const void *a, gint aoff, gint n, const void *b, gint boff, gin
  */
 guint32 compare_diff_distance (f_str_t *s1, f_str_t *s2);
 
+/*
+ * Calculate distance between two strings (in percentage) using diff algorithm. Strings are normalized before:
+ * all spaces are removed and all characters are lowercased.
+ * @return 100 in case of identical strings and 0 in case of totally different strings.
+*/
+guint32 compare_diff_distance_normalized (f_str_t *s1, f_str_t *s2);
+
 #endif /* DIFF_H_ */

src/expressions.c

@@ -1051,7 +1051,7 @@ rspamd_parts_distance (struct worker_task * task, GList * args, void *unused)
 		}
 		if (!p1->is_empty && !p2->is_empty) {
 			if (p1->diff_str != NULL && p2->diff_str != NULL) {
-				diff = compare_diff_distance (p1->diff_str, p2->diff_str);
+				diff = compare_diff_distance_normalized (p1->diff_str, p2->diff_str);
 			}
 			else {
 				diff = fuzzy_compare_parts (p1, p2);