Index: path.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/path/path.module,v
retrieving revision 1.105.2.2
diff -u -p -r1.105.2.2 path.module
--- path.module	11 Feb 2008 05:11:58 -0000	1.105.2.2
+++ path.module	30 Oct 2008 13:20:03 -0000
@@ -143,24 +143,24 @@ function path_set_alias($path = NULL, $a
     $alias_count = db_result(db_query("SELECT COUNT(dst) FROM {url_alias} WHERE dst = '%s'", $alias));
 
     // We have an insert:
-    if ($path_count == 0 && $alias_count == 0) {
+    if (!$path_count && !$alias_count) {
       db_query("INSERT INTO {url_alias} (src, dst) VALUES ('%s', '%s')", $path, $alias);
       drupal_clear_path_cache();
     }
-    else if ($path_count >= 1 && $alias_count == 0) {
+    else if ($path_count && !$alias_count) {
       if ($pid) {
         db_query("UPDATE {url_alias} SET dst = '%s', src = '%s' WHERE pid = %d", $alias, $path, $pid);
       }
       else {
-        db_query("INSERT INTO {url_alias} (src, dst) VALUES ('%s', '%s')", $path, $alias);
+        db_query("UPDATE {url_alias} SET src = '%s', dst = '%s' WHERE src = '%s' OR dst = '%s'", $path, $alias, $path, $alias);
       }
       drupal_clear_path_cache();
     }
-    else if ($path_count == 0 && $alias_count == 1) {
+    else if (!$path_count && $alias_count) {
       db_query("UPDATE {url_alias} SET src = '%s' WHERE dst = '%s'", $path, $alias);
       drupal_clear_path_cache();
     }
-    else if ($path_count == 1 && $alias_count == 1) {
+    else if ($path_count && $alias_count) {
       // This will delete the path that alias was originally pointing to:
       path_set_alias(NULL, $alias);
       path_set_alias($path);