[svn r16523] display a message if datas from tracking are not calculable due to wrong old datas (FS#2741)

main/inc/lib/main_api.lib.php

@@ -2264,6 +2264,12 @@ function api_parse_tex($textext)
 function api_time_to_hms($seconds)
 {
   
+  //if seconds = -1, it means we have wrong datas in the db
+  if($seconds==-1)
+  {
+  	  return get_lang('Unknown').Display :: return_icon('info2.gif',get_lang('WrongDatasForTimeSpentOnThePlatform'));
+  }
+  
   //How many hours ?
   $hours = floor($seconds / 3600);
 

main/inc/lib/tracking.lib.php

@@ -46,12 +46,14 @@ class Tracking {
 		$tbl_track_login = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_LOGIN);
 
 		$sql = 'SELECT login_date, logout_date FROM ' . $tbl_track_login . ' 
-						WHERE login_user_id = ' . intval($user_id).' AND logout_date IS NOT NULL';
+						WHERE login_user_id = ' . intval($user_id);;
 
 		$rs = api_sql_query($sql,__FILE__,__LINE__);
 
 		$nb_seconds = 0;
 		
+		$wrong_logout_dates = false;
+
 		while ($a_connections = Database::fetch_array($rs)) {
 
 			$s_login_date = $a_connections["login_date"];
@@ -60,12 +62,26 @@ class Tracking {
 			$i_timestamp_login_date = strtotime($s_login_date);
 			$i_timestamp_logout_date = strtotime($s_logout_date);
 			
+			if($i_timestamp_logout_date>0)
+			{
 				$nb_seconds += ($i_timestamp_logout_date - $i_timestamp_login_date);
+			}
+			else
+			{ // there are wrong datas in db, then we can't give a wrong time
+				$wrong_logout_dates = true;
+			}
 
 		}
 		
+		if($nb_seconds>0 || !$wrong_logout_dates)
+		{
 			return $nb_seconds;
 		}
+		else
+		{
+			return -1; //-1 means we have wrong datas in the db
+		}
+	}
 
 	/**
 	 * Calculates the time spent on the course