From e1ace26f1114b859b84d2806c86a67f3f6eab79a Mon Sep 17 00:00:00 2001
From: Tim Hunt <T.J.Hunt@open.ac.uk>
Date: Wed, 4 Mar 2015 18:47:59 +0000
Subject: [PATCH] MDL-49389 blocklib: avoid notices when moving blocks to the
 bottom

---
 lib/blocklib.php | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/blocklib.php b/lib/blocklib.php
index 5d1fb248c74..a44c18567ea 100644
--- a/lib/blocklib.php
+++ b/lib/blocklib.php
@@ -1599,8 +1599,10 @@ class block_manager {
         if ($bestgap < $newweight) {
             $newweight = floor($newweight);
             for ($weight = $bestgap + 1; $weight <= $newweight; $weight++) {
-                foreach ($usedweights[$weight] as $biid) {
-                    $this->reposition_block($biid, $newregion, $weight - 1);
+                if (array_key_exists($weight, $usedweights)) {
+                    foreach ($usedweights[$weight] as $biid) {
+                        $this->reposition_block($biid, $newregion, $weight - 1);
+                    }
                 }
             }
             $this->reposition_block($block->instance->id, $newregion, $newweight);