MDL-21432 backup - improve start date offset

diff --git a/backup/util/plan/restore_structure_step.class.php b/backup/util/plan/restore_structure_step.class.php
index 8a1db6c..1eb1d80 100644 (file)
--- a/backup/util/plan/restore_structure_step.class.php
+++ b/backup/util/plan/restore_structure_step.class.php
@@ -277,6 +277,11 @@ abstract class restore_structure_step extends restore_step {
      */
     protected function apply_date_offset($value) {
 
+        // 0 doesn't offset
+        if ($value == 0) {
+            return $value;
+        }
+
         static $cache = array();
         // Lookup cache
         if (isset($cache[$this->get_restoreid()])) {