From 6481b28fe526abbeb8a176cbc2791872192b0fab Mon Sep 17 00:00:00 2001
From: Tim Hunt <T.J.Hunt@open.ac.uk>
Date: Thu, 16 Jun 2011 09:23:43 +0100
Subject: [PATCH] MDL-27878 make progress bars fail explicity if you forget to
 call create().

---
 lib/weblib.php | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/weblib.php b/lib/weblib.php
index fb4b7ea18ad..290cf533d8b 100644
--- a/lib/weblib.php
+++ b/lib/weblib.php
@@ -3060,8 +3060,9 @@ EOT;
      * @return void Echo's output
      */
     private function _update($percent, $msg) {
-        if (empty($this->time_start)){
-            $this->time_start = microtime(true);
+        if (empty($this->time_start)) {
+            throw new coding_exception('You must call create() (or use the $autostart ' .
+                    'argument to the constructor) before you try updating the progress bar.');
         }
 
         if (CLI_SCRIPT) {