Several bug fixes

* Batch Manager no longer have a php error
 * Intro Graph display the actual week when it's monday
 * fix the "groups" reserved word
 * History is now summarize on the stats pag access
 * New piwigo no longer have PHP error due to stats.php

admin/batch_manager_global.php

@@ -453,6 +453,11 @@ if ($conf['enable_synchronization'])
   $prefilters[] = array('ID' => 'no_sync_md5sum', 'NAME' => l10n('With no checksum'));
 }
 
+function UC_name_compare($a, $b)
+{
+  return strcmp(strtolower($a['NAME']), strtolower($b['NAME']));
+}
+
 $prefilters = trigger_change('get_batch_manager_prefilters', $prefilters);
 usort($prefilters, 'UC_name_compare');
 

admin/intro.php

@@ -205,13 +205,13 @@ $temp_data = array();
 //Get data from $nb_weeks last weeks
 while ($mondays < $nb_weeks) 
 {
-  $date->sub(new DateInterval('P1D'));
-
   if ($date->format('D') == 'Mon') 
   {
     $week_number[] = $date->format('W');
     $mondays += 1;
   }
+
+  $date->sub(new DateInterval('P1D'));
 }
 
 $week_number = array_reverse($week_number);
@@ -284,10 +284,13 @@ for ($i=1; $i < count($temp_data); $i++)
 
 $split = 0;
 //Split (split represented by -1)
-while (max($diff_x) > 120) 
+if (count($diff_x) > 0) 
 {
-  $diff_x[array_search(max($diff_x), $diff_x)] = -1;
-  $split++;
+  while (max($diff_x) > 120) 
+  {
+    $diff_x[array_search(max($diff_x), $diff_x)] = -1;
+    $split++;
+  }
 }
 
 //Fill empty chart data for the template

admin/stats.php

@@ -216,7 +216,7 @@ check_status(ACCESS_ADMINISTRATOR);
 // | Refresh summary from details                                          |
 // +-----------------------------------------------------------------------+
 
-//history_summarize();
+history_summarize();
 
 // +-----------------------------------------------------------------------+
 // | Display statistics header                                             |                                                                                            
@@ -242,6 +242,11 @@ $template->assign(
 
 function set_missing_values($unit, $data, $keep_size=true, $firstDate = null, $lastDate = null)
 {
+  if (count($data) <= 1) 
+  {
+    return $data;
+  }
+
   $limit = count($data);
   $result = array();
   if ($firstDate == null)