BUG#1244 Use a UNION to improve index use.

diff --git a/includes/Block.php b/includes/Block.php
index 3b4916c..3f0ed48 100644 (file)
--- a/includes/Block.php
+++ b/includes/Block.php
@@ -76,7 +76,14 @@ class Block
                        $sql = "SELECT * FROM $ipblocks WHERE ipb_user={$user} $options";
                } elseif ($user=="") {
                        $sql = "SELECT * FROM $ipblocks WHERE ipb_address='" . $db->strencode( $address ) . "' $options";
+               } elseif ( $options=='' ) {
+                       # If there are no optiones (e.g. FOR UPDATE), use a UNION
+                       # so that the query can make efficient use of indices
+                       $sql = "SELECT * FROM $ipblocks WHERE ipb_address='" . $db->strencode( $address ) .
+                               "' UNION SELECT * FROM $ipblocks WHERE ipb_user={$user}";
                } else {
+                       # If there are options, a UNION can not be used, use one
+                       # SELECT instead. Will do a full table scan.
                        $sql = "SELECT * FROM $ipblocks WHERE (ipb_address='" . $db->strencode( $address ) . 
                                "' OR ipb_user={$user}) $options";
                }