fixed serious breakage during upgrades caused by double redirects

admin/config.php

@@ -3,6 +3,8 @@
 
     require_once('../config.php');
 
+    $installing = optional_param('installing', 0, PARAM_BOOL);
+
     $focus = '';
 
     if ($site = get_site()) {   // If false then this is a new installation
@@ -63,8 +65,16 @@
                     }
                 }
             }
-            redirect('index.php', get_string('changessaved'), 1);
-            exit;
+            if ($installing) {
+                print_header();
+                notify(get_string('changessaved'), 'notifysuccess');
+                print_continue('index.php');
+                exit;
+            } else {
+                // the following redirect was randomly breaking upgrades because it did double redirects,
+                // we must not use it during install/upgrade
+                redirect('index.php', get_string('changessaved'), 1);
+            }
 
         } else {
             foreach ($err as $key => $value) {
@@ -143,6 +153,7 @@
 
     }
     echo '<center>';
+    echo '<input type="hidden" name="installing" value="'.$installing.'" />';
     echo '<input type="hidden" name="sesskey" value="'.$sesskey.'" />';
     echo '<input type="submit" value="'.get_string('savechanges').'" />';
     echo '</center>';

admin/index.php

@@ -222,7 +222,7 @@
 /// If any new configurations were found then send to the config page to check
 
     if (!empty($configchange)) {
-        redirect("config.php");
+        redirect("config.php?installing=1");
     }
 
 /// Find and check all main modules and load them up or upgrade them if necessary
@@ -323,6 +323,9 @@
         print_simple_box(get_string('globalsquoteswarning', 'admin'), 'center', '60%');
     }
 
+    if (is_dataroot_insecure()) {
+        print_simple_box(get_string('datarootsecuritywarning', 'admin', $CFG->dataroot), 'center', '60%');
+    }
 
 /// If no recently cron run
     $lastcron = get_field_sql('SELECT max(lastcron) FROM ' . $CFG->prefix . 'modules');